Microtubules are cytoskeletal structures that maintain cell shape and facilitate intracellular transport. They are composed of tubulin subunits and are polarized, with microtubule-associated proteins regulating their assembly and stability. Motor proteins like kinesin and dynein move along microtubules to transport vesicles and organelles within cells. Microtubules are nucleated from the centrosome and organize into the mitotic spindle during cell division to separate chromosomes between daughter cells.
The cytoskeleton is a network of protein filaments that extends throughout the cytoplasm. It provides structure and organization to the cell, determining shape and positioning organelles. The three main types of filaments are actin filaments, intermediate filaments, and microtubules. Actin filaments are the thinnest filaments and form structures like filopodia, lamellipodia, and stress fibers. Microtubules are hollow cylinders composed of tubulin dimers and originate from the centrosome. They are involved in processes like cell division, organelle transport, and motility. Cilia and flagella project from the cell surface and use microtubule motors for movement.
Details of cytoskeleton element-microtubule. The Microtubule associated protein-type and function, Treadmilling and dynamic instability, Structure of cilia and flagella
Cell signaling involves the use of signaling molecules to transmit information between cells. These molecules can be classified as extracellular signals, like peptides, lipids, gases, and small hydrophilic molecules, or intracellular second messengers like cAMP and calcium. Extracellular signals bind to cell surface receptors and trigger intracellular pathways that regulate cell function and development. Signaling can occur through endocrine, paracrine, or autocrine pathways depending on the distance over which the signal acts. Important examples of signaling molecules discussed include peptide hormones, steroid hormones, prostaglandins, and nitric oxide. Intracellular signaling molecules like G proteins and protein kinases transmit and amplify extracellular signals within cells through the use of feedback loops and molecular switches. Breakdowns
The document discusses the cytoskeleton of eukaryotic cells. It provides information on the history, structure, and functions of the three main cytoskeletal components: microtubules, microfilaments, and intermediate filaments. Microtubules are hollow rods that help with intracellular transport and cell division. Microfilaments are made of actin and involved in cell motility and muscle contraction. Intermediate filaments provide mechanical strength and resist stresses on the cell.
The document summarizes programmed cell death or apoptosis. It describes apoptosis as a naturally occurring, genetically programmed process where a cell undergoes an organized breakdown. During apoptosis, cells shrink, break into membrane-bound fragments called apoptotic bodies, and are removed by phagocytes without causing inflammation. The document outlines the major pathways of apoptosis, including the intrinsic mitochondrial pathway and extrinsic death receptor pathway, and discusses the roles of caspase proteases and Bcl-2 family proteins in apoptosis signaling and regulation.
The document discusses protein folding, which is the process by which a polypeptide chain folds into its characteristic and functional three-dimensional structure. It describes the four levels of protein structure: primary, secondary, tertiary, and quaternary. Key drivers of folding are the hydrophobic effect and formation of hydrogen bonds. Chaperone proteins assist in protein folding in vivo. Factors such as mutations, errors in synthesis, environmental stresses, and aging can cause proteins to misfold and aggregate, which is associated with various diseases. Cells use molecular chaperones and protein degradation systems to prevent aggregation, but these become less effective with age.
This document discusses cell adhesion molecules (CAMs), which are glycoproteins located on cell surfaces that help cells stick to each other and their surroundings. CAMs are classified into five major families: cadherins, Ig superfamily CAMs, selectins, integrins, and mucins. Cadherins are calcium-dependent and form connections between cells called desmosomes. Selectins help with inflammation and lymphocyte homing. Integrins facilitate cell-cell and cell-extracellular matrix adhesion and are composed of alpha and beta subunits. Malfunctions in CAMs can lead to conditions like breast cancer and leukocyte adhesion deficiency syndrome.
The extracellular matrix (ECM) provides physical scaffolding and biochemical signals outside cells that are essential for tissue development and homeostasis. The ECM is composed of glycoproteins like collagen and proteoglycans that form a network, as well as glycoproteins like fibronectin that attach cells to the network. Collagen provides tensile strength and there are various types of collagen with different structures and functions. The ECM allows communication between cells through connections like tight junctions, desmosomes, and gap junctions. It also binds growth factors and interacts with cell receptors to regulate gene expression. Disruptions to the ECM can cause diseases like scurvy or emphysema.
The cytoskeleton is a network of protein filaments that extends throughout the cytoplasm. It provides structure and organization to the cell, determining shape and positioning organelles. The three main types of filaments are actin filaments, intermediate filaments, and microtubules. Actin filaments are the thinnest filaments and form structures like filopodia, lamellipodia, and stress fibers. Microtubules are hollow cylinders composed of tubulin dimers and originate from the centrosome. They are involved in processes like cell division, organelle transport, and motility. Cilia and flagella project from the cell surface and use microtubule motors for movement.
Details of cytoskeleton element-microtubule. The Microtubule associated protein-type and function, Treadmilling and dynamic instability, Structure of cilia and flagella
Cell signaling involves the use of signaling molecules to transmit information between cells. These molecules can be classified as extracellular signals, like peptides, lipids, gases, and small hydrophilic molecules, or intracellular second messengers like cAMP and calcium. Extracellular signals bind to cell surface receptors and trigger intracellular pathways that regulate cell function and development. Signaling can occur through endocrine, paracrine, or autocrine pathways depending on the distance over which the signal acts. Important examples of signaling molecules discussed include peptide hormones, steroid hormones, prostaglandins, and nitric oxide. Intracellular signaling molecules like G proteins and protein kinases transmit and amplify extracellular signals within cells through the use of feedback loops and molecular switches. Breakdowns
The document discusses the cytoskeleton of eukaryotic cells. It provides information on the history, structure, and functions of the three main cytoskeletal components: microtubules, microfilaments, and intermediate filaments. Microtubules are hollow rods that help with intracellular transport and cell division. Microfilaments are made of actin and involved in cell motility and muscle contraction. Intermediate filaments provide mechanical strength and resist stresses on the cell.
The document summarizes programmed cell death or apoptosis. It describes apoptosis as a naturally occurring, genetically programmed process where a cell undergoes an organized breakdown. During apoptosis, cells shrink, break into membrane-bound fragments called apoptotic bodies, and are removed by phagocytes without causing inflammation. The document outlines the major pathways of apoptosis, including the intrinsic mitochondrial pathway and extrinsic death receptor pathway, and discusses the roles of caspase proteases and Bcl-2 family proteins in apoptosis signaling and regulation.
The document discusses protein folding, which is the process by which a polypeptide chain folds into its characteristic and functional three-dimensional structure. It describes the four levels of protein structure: primary, secondary, tertiary, and quaternary. Key drivers of folding are the hydrophobic effect and formation of hydrogen bonds. Chaperone proteins assist in protein folding in vivo. Factors such as mutations, errors in synthesis, environmental stresses, and aging can cause proteins to misfold and aggregate, which is associated with various diseases. Cells use molecular chaperones and protein degradation systems to prevent aggregation, but these become less effective with age.
This document discusses cell adhesion molecules (CAMs), which are glycoproteins located on cell surfaces that help cells stick to each other and their surroundings. CAMs are classified into five major families: cadherins, Ig superfamily CAMs, selectins, integrins, and mucins. Cadherins are calcium-dependent and form connections between cells called desmosomes. Selectins help with inflammation and lymphocyte homing. Integrins facilitate cell-cell and cell-extracellular matrix adhesion and are composed of alpha and beta subunits. Malfunctions in CAMs can lead to conditions like breast cancer and leukocyte adhesion deficiency syndrome.
The extracellular matrix (ECM) provides physical scaffolding and biochemical signals outside cells that are essential for tissue development and homeostasis. The ECM is composed of glycoproteins like collagen and proteoglycans that form a network, as well as glycoproteins like fibronectin that attach cells to the network. Collagen provides tensile strength and there are various types of collagen with different structures and functions. The ECM allows communication between cells through connections like tight junctions, desmosomes, and gap junctions. It also binds growth factors and interacts with cell receptors to regulate gene expression. Disruptions to the ECM can cause diseases like scurvy or emphysema.
A membrane protein is a protein molecule that is attached to, or associated with the membrane of a cell or an organelle.
More than half of all proteins interact with membranes.
1) Actin microfilaments are composed of globular actin subunits that polymerize to form filaments approximately 8 nm in diameter.
2) Actin polymerization is regulated by actin-binding proteins that nucleate, depolymerize, sever, cross-link, or cap actin filaments.
3) In nonmuscle and muscle cells, actin microfilaments interact with myosin to generate forces responsible for cell motility, shape changes, and muscle contraction.
The document summarizes the structure and function of microtubules in eukaryotic cells. It discusses how microtubules are composed of protein subunits that assemble into hollow tubes. Microtubules emanate from microtubule organizing centers and serve important roles as structural supports, in intracellular transport through motor proteins like kinesin and dynein, and in cell division through formation of the mitotic spindle. Microtubules are also the main components of cilia and flagella and enable their bending movements through the motor protein dynein.
Kinesins and dyneins are motor proteins that move along microtubules. Kinesins move cargo from the center of the cell to its periphery by moving toward the plus end of microtubules. Dyneins move cargo from the periphery to the center by moving toward the minus end of microtubules. Both use ATP hydrolysis to power their movement in 8 nm steps along microtubules in opposite directions. Dyneins are also responsible for the bending movement of cilia and flagella by generating force between adjacent microtubule doublets.
Motor molecules also carry vesicles or organelles to various destinations along “monorails’ provided by the cytoskeleton.
Interactions of motor proteins and the cytoskeleton circulates materials within a cell via streaming.
Recently, evidence is accumulating that the cytoskeleton may transmit mechanical signals that re-arrange the nucleoli and other structures.
The document summarizes the structure and functions of the Golgi apparatus. It notes that the Golgi apparatus was discovered in 1898 by Camillo Golgi and is present in all eukaryotic cells. It has a central stack of flattened, interconnecting sacs called cisternae. The Golgi apparatus modifies proteins and lipids from the ER, carrying out functions like secretion, synthesis, sulfation, phosphorylation, and apoptosis. It packages molecules into vesicles which are transported within the cell.
This document discusses the purification of proteins. It begins with an introduction to proteins and their structures. It then discusses various techniques used to purify proteins, including salting out, dialysis, gel filtration chromatography, ion-exchange chromatography, gel electrophoresis, isoelectric focusing, and HPLC. The key techniques discussed in detail are salting out, dialysis, gel filtration chromatography, ion-exchange chromatography, gel electrophoresis, and affinity chromatography. The document emphasizes that different techniques are used to purify proteins based on their properties such as solubility, molecular size, ionic charge, and binding specificity.
Presentation on Electrical Properties of Cell MembraneRubinaRoy1
Cell membrane has the characteristic property to receive stimulus and convey the message through electrical signals, itself getting depolarized and repolarized.
1. The cytoskeleton is a network of fibers that organizes cell structures and activities.
2. It is composed of three main types of fibers: microtubules, microfilaments, and intermediate filaments.
3. Microtubules are hollow tubes that help maintain cell shape and enable intracellular transport. Microfilaments are thin fibers involved in cell motility and structure. Intermediate filaments provide mechanical strength and anchor organelles.
Abzymes, also known as catalytic antibodies, are monoclonal antibodies that exhibit enzymatic activity. They are able to bind to transition states of enzyme-catalyzed reactions with high specificity and affinity, stabilizing the transition state and increasing reaction rates. Abzymes can be artificially produced by immunizing animals with transition state analogs of reactions. They have potential applications in drug development, cancer treatment, and developing therapies for viral infections like HIV. Researchers have engineered an abzyme that can degrade an essential region of the HIV envelope protein, rendering the virus unable to infect cells.
1) Apoptosis is a process of programmed cell death that is important for normal development and physiology, as it helps remove excess, damaged, or dangerous cells.
2) It occurs through intrinsic and extrinsic pathways that involve caspase proteases and results in characteristic cell changes like blebbing and nuclear fragmentation.
3) Between 50-70 billion cells die per day in humans due to apoptosis, which is critical for processes like immune system maturation and tissue remodeling.
The document discusses the key components of the cytoskeleton - microtubules, microfilaments, and intermediate filaments - and how they work together to maintain cell shape, allow movement of organelles and vesicles, transport materials within the cell, and enable cell movement through polymerization and interaction with motor proteins like myosin and kinesin. The cytoskeleton is a dynamic network that forms various structures through accessory proteins and allows rapid changes in cell morphology.
The extracellular matrix (ECM) is a collection of molecules secreted by cells that provides structural and biochemical support to surrounding cells. It is composed of water, proteins, and polysaccharides. The ECM contains collagens, fibronectin, laminins, and proteoglycans. Collagen is the most abundant protein in the ECM and forms fibrils that provide structure. The ECM regulates cell behavior, provides tissue structure and strength, and mediates cell signaling and homeostasis. Genetic defects in ECM proteins can cause diseases like osteogenesis imperfecta or fibrosis.
The document summarizes key aspects of the cytoskeleton, focusing on actin filaments. It describes how actin filaments: 1) maintain cell shape and generate force for cell movements through polymerization and depolymerization; 2) integrate cells through attachments to cell adhesions; and 3) produce movements within cells and at the cell membrane through interactions with myosin motor proteins. Accessory proteins regulate actin dynamics by capping, bundling, severing, and crosslinking filaments.
The nuclear envelope consists of two parallel membranes separated by 10-50 nm. It serves as a barrier between the nucleus and cytoplasm. Nuclear pores are circular complexes of proteins that form openings in the nuclear envelope, allowing transport of molecules between the nucleus and cytoplasm. The nuclear envelope forms through the recruitment of membrane vesicles to chromatin, fusion of these vesicles, and assembly of nuclear pore complexes. Key proteins like POM121 and NDC1 are essential for nuclear pore complex assembly after the formation of the double nuclear membrane.
The document discusses the extracellular matrix (ECM), which provides structural and biochemical support to surrounding cells. It is composed of proteins, enzymes and glycoproteins such as collagen, fibronectin and laminin. The ECM regulates cell communication, stores growth factors, and influences cell behavior through mechanical properties. Defects in ECM proteins can cause connective tissue disorders like Marfan syndrome, osteogenesis imperfecta and Ehlers-Danlos syndrome. The ECM is important for tissue development, wound healing and has applications in medicine.
Cell adhesion molecules help cells stick to each other and their surroundings through proteins. There are several types of cell adhesion molecules including immunoglobulin super family CAMs, integrins, selectins, and cadherins. Cadherins like E-cadherin form adherens junctions between cells and link to actin through catenins. Changes in cell adhesion can lead to diseases such as cancer where reduced adhesion allows cancer cells to invade other tissues. Cell adhesion molecules are important for tissue development and function.
This document discusses microtubules and their role in cell movement. It describes how vincristine and vinblastine inhibit microtubule polymerization and cell division in rapidly dividing cells. It also discusses dynamic instability in microtubule growth and shrinkage cycles. The document outlines how microtubules extend from the centrosome in animal cells and form the mitotic spindle. It describes the structure of the centrosome and centrioles, and how gamma-tubulin nucleates microtubule assembly. Finally, it briefly summarizes microtubule organization in cells and their role in processes like cargo transport, cilia/flagella movement, and chromosome movement during mitosis.
Microtubules are filamentous structures in cells that serve as tracks for transporting organelles and vesicles. They are composed of tubulin subunits that can assemble and disassemble dynamically. This allows microtubules to remodel rapidly during cell division and change structure. Motor proteins move along microtubules to transport cargo within cells. Microtubules interact with other cellular components through microtubule associated proteins (MAPs) that can stabilize microtubule structure.
A membrane protein is a protein molecule that is attached to, or associated with the membrane of a cell or an organelle.
More than half of all proteins interact with membranes.
1) Actin microfilaments are composed of globular actin subunits that polymerize to form filaments approximately 8 nm in diameter.
2) Actin polymerization is regulated by actin-binding proteins that nucleate, depolymerize, sever, cross-link, or cap actin filaments.
3) In nonmuscle and muscle cells, actin microfilaments interact with myosin to generate forces responsible for cell motility, shape changes, and muscle contraction.
The document summarizes the structure and function of microtubules in eukaryotic cells. It discusses how microtubules are composed of protein subunits that assemble into hollow tubes. Microtubules emanate from microtubule organizing centers and serve important roles as structural supports, in intracellular transport through motor proteins like kinesin and dynein, and in cell division through formation of the mitotic spindle. Microtubules are also the main components of cilia and flagella and enable their bending movements through the motor protein dynein.
Kinesins and dyneins are motor proteins that move along microtubules. Kinesins move cargo from the center of the cell to its periphery by moving toward the plus end of microtubules. Dyneins move cargo from the periphery to the center by moving toward the minus end of microtubules. Both use ATP hydrolysis to power their movement in 8 nm steps along microtubules in opposite directions. Dyneins are also responsible for the bending movement of cilia and flagella by generating force between adjacent microtubule doublets.
Motor molecules also carry vesicles or organelles to various destinations along “monorails’ provided by the cytoskeleton.
Interactions of motor proteins and the cytoskeleton circulates materials within a cell via streaming.
Recently, evidence is accumulating that the cytoskeleton may transmit mechanical signals that re-arrange the nucleoli and other structures.
The document summarizes the structure and functions of the Golgi apparatus. It notes that the Golgi apparatus was discovered in 1898 by Camillo Golgi and is present in all eukaryotic cells. It has a central stack of flattened, interconnecting sacs called cisternae. The Golgi apparatus modifies proteins and lipids from the ER, carrying out functions like secretion, synthesis, sulfation, phosphorylation, and apoptosis. It packages molecules into vesicles which are transported within the cell.
This document discusses the purification of proteins. It begins with an introduction to proteins and their structures. It then discusses various techniques used to purify proteins, including salting out, dialysis, gel filtration chromatography, ion-exchange chromatography, gel electrophoresis, isoelectric focusing, and HPLC. The key techniques discussed in detail are salting out, dialysis, gel filtration chromatography, ion-exchange chromatography, gel electrophoresis, and affinity chromatography. The document emphasizes that different techniques are used to purify proteins based on their properties such as solubility, molecular size, ionic charge, and binding specificity.
Presentation on Electrical Properties of Cell MembraneRubinaRoy1
Cell membrane has the characteristic property to receive stimulus and convey the message through electrical signals, itself getting depolarized and repolarized.
1. The cytoskeleton is a network of fibers that organizes cell structures and activities.
2. It is composed of three main types of fibers: microtubules, microfilaments, and intermediate filaments.
3. Microtubules are hollow tubes that help maintain cell shape and enable intracellular transport. Microfilaments are thin fibers involved in cell motility and structure. Intermediate filaments provide mechanical strength and anchor organelles.
Abzymes, also known as catalytic antibodies, are monoclonal antibodies that exhibit enzymatic activity. They are able to bind to transition states of enzyme-catalyzed reactions with high specificity and affinity, stabilizing the transition state and increasing reaction rates. Abzymes can be artificially produced by immunizing animals with transition state analogs of reactions. They have potential applications in drug development, cancer treatment, and developing therapies for viral infections like HIV. Researchers have engineered an abzyme that can degrade an essential region of the HIV envelope protein, rendering the virus unable to infect cells.
1) Apoptosis is a process of programmed cell death that is important for normal development and physiology, as it helps remove excess, damaged, or dangerous cells.
2) It occurs through intrinsic and extrinsic pathways that involve caspase proteases and results in characteristic cell changes like blebbing and nuclear fragmentation.
3) Between 50-70 billion cells die per day in humans due to apoptosis, which is critical for processes like immune system maturation and tissue remodeling.
The document discusses the key components of the cytoskeleton - microtubules, microfilaments, and intermediate filaments - and how they work together to maintain cell shape, allow movement of organelles and vesicles, transport materials within the cell, and enable cell movement through polymerization and interaction with motor proteins like myosin and kinesin. The cytoskeleton is a dynamic network that forms various structures through accessory proteins and allows rapid changes in cell morphology.
The extracellular matrix (ECM) is a collection of molecules secreted by cells that provides structural and biochemical support to surrounding cells. It is composed of water, proteins, and polysaccharides. The ECM contains collagens, fibronectin, laminins, and proteoglycans. Collagen is the most abundant protein in the ECM and forms fibrils that provide structure. The ECM regulates cell behavior, provides tissue structure and strength, and mediates cell signaling and homeostasis. Genetic defects in ECM proteins can cause diseases like osteogenesis imperfecta or fibrosis.
The document summarizes key aspects of the cytoskeleton, focusing on actin filaments. It describes how actin filaments: 1) maintain cell shape and generate force for cell movements through polymerization and depolymerization; 2) integrate cells through attachments to cell adhesions; and 3) produce movements within cells and at the cell membrane through interactions with myosin motor proteins. Accessory proteins regulate actin dynamics by capping, bundling, severing, and crosslinking filaments.
The nuclear envelope consists of two parallel membranes separated by 10-50 nm. It serves as a barrier between the nucleus and cytoplasm. Nuclear pores are circular complexes of proteins that form openings in the nuclear envelope, allowing transport of molecules between the nucleus and cytoplasm. The nuclear envelope forms through the recruitment of membrane vesicles to chromatin, fusion of these vesicles, and assembly of nuclear pore complexes. Key proteins like POM121 and NDC1 are essential for nuclear pore complex assembly after the formation of the double nuclear membrane.
The document discusses the extracellular matrix (ECM), which provides structural and biochemical support to surrounding cells. It is composed of proteins, enzymes and glycoproteins such as collagen, fibronectin and laminin. The ECM regulates cell communication, stores growth factors, and influences cell behavior through mechanical properties. Defects in ECM proteins can cause connective tissue disorders like Marfan syndrome, osteogenesis imperfecta and Ehlers-Danlos syndrome. The ECM is important for tissue development, wound healing and has applications in medicine.
Cell adhesion molecules help cells stick to each other and their surroundings through proteins. There are several types of cell adhesion molecules including immunoglobulin super family CAMs, integrins, selectins, and cadherins. Cadherins like E-cadherin form adherens junctions between cells and link to actin through catenins. Changes in cell adhesion can lead to diseases such as cancer where reduced adhesion allows cancer cells to invade other tissues. Cell adhesion molecules are important for tissue development and function.
This document discusses microtubules and their role in cell movement. It describes how vincristine and vinblastine inhibit microtubule polymerization and cell division in rapidly dividing cells. It also discusses dynamic instability in microtubule growth and shrinkage cycles. The document outlines how microtubules extend from the centrosome in animal cells and form the mitotic spindle. It describes the structure of the centrosome and centrioles, and how gamma-tubulin nucleates microtubule assembly. Finally, it briefly summarizes microtubule organization in cells and their role in processes like cargo transport, cilia/flagella movement, and chromosome movement during mitosis.
Microtubules are filamentous structures in cells that serve as tracks for transporting organelles and vesicles. They are composed of tubulin subunits that can assemble and disassemble dynamically. This allows microtubules to remodel rapidly during cell division and change structure. Motor proteins move along microtubules to transport cargo within cells. Microtubules interact with other cellular components through microtubule associated proteins (MAPs) that can stabilize microtubule structure.
This document provides an outline for Chapter 4 of the biology textbook "Cell Structure and Function" by Sylvia S. Mader and Michael Windelspecht. The outline covers topics including the cellular level of organization, prokaryotic and eukaryotic cells, organelles such as the nucleus, endomembrane system, cytoskeleton, and energy-related organelles. Diagrams are included to illustrate cell structures like plant and animal cells as well as different types of microscopes used to study cells.
This document summarizes a research team working on mathematical modeling and drug development for cancer treatment. The team is developing computational models of cancer processes and treatments to identify new chemotherapy compounds and improve treatment outcomes. Their work focuses on modeling microtubules and developing drugs that selectively target microtubule isoforms expressed in cancer cells. They use techniques like quantum mechanics, molecular dynamics simulations, and hybrid quantum/molecular mechanics methods to model drug-microtubule interactions and design new drugs. The overall goal is to leverage computational modeling to develop patient-specific cancer treatments.
Microtubules are thick protein tubes composed of subunits called tubulin. They function to transport vesicles and organelles within cells, assist in cell division and motility, and help maintain intracellular structure. Microtubules are essential components of eukaryotic cells that participate in nucleic and cell division, organization of intracellular structure, and transport, as well as cell motility.
The cytoskeleton is made up of 3 main components that provide structure and allow movement in eukaryotic cells. Microfilaments are the thinnest and composed of actin, intermediate filaments provide mechanical strength, and microtubules are hollow tubes important for cell division and intracellular transport. Together these components maintain cell shape and allow organelles and the cell itself to move.
The cytoskeleton is a network of fibers that extends throughout the cytoplasm and provides structural support to the cell. It is composed of three main types of fibers - microtubules, microfilaments, and intermediate filaments. The cytoskeleton also functions in cell motility through motor proteins that interact with the fibers to transport vesicles and organelles within the cell. It plays an important role in cell division and shape change.
The cytoskeleton is the internal framework of the cell composed of protein filaments and microtubules. It maintains cell shape, protects the cell, enables cellular motion and mechanical support, and aids in cell motility. Microtubules consist of hollow tubes made of tubulin molecules, while microfilaments consist of two intertwined strands of actin.
Centrioles are cylindrical structures found in animal cells composed of nine triplets of microtubules arranged in a 9+3 pattern. They are located in the centrosome and replicate during cell division to form two centrosomes that help organize the mitotic spindle. In plant cells, centrosomes are present but centrioles are absent. Centrioles also function as basal bodies to form cilia and flagella and help determine cell polarity.
The document discusses the cytoskeleton, which is a network of protein filaments found in eukaryotic cells that helps maintain cell shape and enable cell movement. It is composed of microtubules, actin filaments, and intermediate filaments. Microtubules are hollow tubes made of tubulin proteins. Actin filaments are thin filaments made of actin proteins. Intermediate filaments are made of various fibrous proteins. Together, these filaments form a scaffolding that supports and shapes the cell. The cytoskeleton also enables cellular processes like intracellular transport, cell division, and cell movement.
Microtubules are cytoskeletal structures composed of tubulin subunits that form polarized protofilaments. They function to maintain cell shape and facilitate intracellular transport. Microtubules are dynamic and can grow or shrink rapidly via tubulin addition or removal. They are involved in mitosis and cell division through formation of the mitotic spindle. Motor proteins such as kinesin and dynein move along microtubules to transport vesicles and organelles within cells. The centrosome nucleates microtubule growth and organization.
The document discusses the cytoskeleton, which is composed of microfilaments, intermediate filaments, and microtubules. Microfilaments are composed of actin and are involved in cell motility and structure. Intermediate filaments provide mechanical strength and support cellular structures. Microtubules are composed of tubulin and are involved in maintaining cell shape and intracellular transport. The cytoskeleton is a dynamic network that maintains cell structure and enables various cell functions and movements.
The document discusses the cytoskeleton, which is made up of microtubules, intermediate filaments, and microfilaments. Microtubules provide structure to cilia and flagella. Intermediate filaments help maintain the cell's shape. Microfilaments are made of actin and are involved in muscle cell contraction, extending pseudopodia, and cytoplasmic streaming in plant cells. Myosin interacts with actin to generate movement and contraction within cells.
Cells are the basic structural and functional units of all living organisms. There are two main types of cells - prokaryotic cells, which lack a nucleus, and eukaryotic cells, which have a nucleus surrounded by a nuclear envelope. The plasma membrane surrounds the cell and acts as a selectively permeable barrier that regulates what enters and exits the cell. Transport across the membrane can occur through passive diffusion, facilitated diffusion, or active transport processes that require energy. Vesicle transport is also used to move materials within and between cells.
The document summarizes the structure and function of organelles found within eukaryotic cells. It describes the cytoplasm and cytosol as well as various membrane-bound organelles including mitochondria, ribosomes, the endoplasmic reticulum, cilia and flagella, the nucleus, the Golgi apparatus, lysosomes, and the cytoskeleton. It also mentions cell walls, vacuoles, chloroplasts, and their respective functions in cellular structure and processes.
The plasma membrane maintains the internal environment of cells by regulating what enters and exits. It is composed primarily of a phospholipid bilayer with embedded protein molecules and cholesterol. The membrane is selectively permeable and uses both passive and active transport mechanisms to control molecular movement in and out of cells.
1) Microtubules switch between growing and shrinking phases due to a process called dynamic instability. This allows microtubules to rearrange during cell division and development. 2) Microtubule growth is driven by the binding of GTP-bound tubulin dimers, while shrinking is driven by the release of strained GDP-bound dimers following GTP hydrolysis. 3) The microtubule plus end acts like a molecular machine, using the energy from GTP hydrolysis to power conformational changes between a flattened structure during growth and a frayed structure during shrinkage.
The document discusses the cytoskeleton of eukaryotic cells. It provides background on the history and components of the cytoskeleton. The cytoskeleton consists of three main types of fibers - microtubules, microfilaments, and intermediate filaments. Microtubules are hollow rods that help with cell structure and mobility. Microfilaments are made of actin and resist tension. Intermediate filaments are specialized for bearing tension and maintaining cell shape.
The cytoskeleton is composed of three main elements - microfilaments, microtubules, and intermediate filaments. Microfilaments are composed of actin and are involved in cell motility. Microtubules are composed of tubulin and form rigid hollow cylinders that help maintain cell shape and transport organelles within cells. Motor proteins like kinesin and dynein interact with cytoskeletal elements to transport materials. The cytoskeleton provides structure, helps position organelles, transports materials, and generates the forces necessary for cell movement.
1) Microtubules grow by the addition of tubulin dimers to the plus end, with polymerization favored at this end. The plus end carries a GTP cap that stabilizes the microtubule.
2) Microtubules undergo treadmilling as the GTP cap moves down the length of the microtubule until reaching the minus end, where GTP is hydrolyzed.
3) Dynamic instability occurs when a microtubule switches between growth and shrinkage, providing a source of tubulin for other microtubules. Growing microtubules are favored when GTP-tubulin concentrations are high.
1) The cell cycle consists of interphase and M phase. Interphase includes G1, S, and G2 phases where the cell grows and DNA replicates in S phase.
2) M phase comprises mitosis and cytokinesis where the cell divides into two daughter cells. Mitosis takes place in four phases - prophase, metaphase, anaphase, and telophase where chromosomes are aligned and separated.
3) Cytokinesis then partitions the cytoplasm, organelles and cell membrane, finalizing the production of two identical daughter cells from the original parent cell.
1) The cell cycle consists of interphase and M phase. Interphase includes G1, S, and G2 phases where the cell grows and DNA replicates. M phase is when the cell divides, including mitosis and cytokinesis.
2) Mitosis is divided into prophase, metaphase, anaphase, and telophase where the chromosomes condense and align, separate, and decondense respectively.
3) The cell cycle is tightly regulated by cyclins and cyclin-dependent kinases which promote phase transitions when cyclin levels rise and fall.
The cytoskeleton is a network of fibers that organizes cell structures and activities. It is composed of three main types of fibers: microtubules, microfilaments, and intermediate filaments. Microtubules are the thickest fibers and help maintain cell shape. They also interact with motor proteins to transport vesicles within cells. Intermediate filaments provide mechanical strength and resist shear stress.
The document summarizes the three main types of cytoskeletal structures - microtubules, microfilaments, and intermediate filaments. It describes their protein composition, assembly, organization into networks within cells, and key functions like providing structure, enabling cell movement and division. Microtubules are rigid hollow tubes that help determine cell shape and transport organelles, while microfilaments composed of actin filaments enable muscle contraction and cell movement. Intermediate filaments provide mechanical strength and support nuclear positioning.
1. Kinesins and dyneins are microtubule motor proteins that transport cargo within cells. Kinesins move toward microtubule plus ends while dyneins move toward minus ends.
2. Kinesins have a globular motor domain and use ATP hydrolysis to undergo conformational changes that power their movement. They transport diverse cargo including vesicles and organelles.
3. Dyneins are large, complex motors that also use ATP hydrolysis to power transport toward microtubule minus ends, including retrograde vesicle transport. Both kinesins and dyneins play important roles in mitosis and intracellular transport.
Mitosis is a process of cell division taking place in prokaryotes and eukaryotes. It is also known as a equational division as the number of chromosomes are identical in parent and daughter cell. There are four phases of mitosis- Prophase, Metaphase, anaphase and telophase which is followed by cytokinesis process.
Microtubules are cytoskeletal structures found in eukaryotic cells that are composed of tubulin protein subunits arranged in protofilaments. They have an outer diameter of 25nm and a wall thickness of 4nm. When viewed in cross section, microtubules reveal 13 protofilaments arranged in a circular pattern. Microtubules help maintain cell shape and are involved in important cellular processes like intracellular transport, cell division, and motility. Motor proteins like kinesins and dyneins interact with microtubules to transport vesicles and organelles through the cytoplasm using ATP hydrolysis as an energy source.
1. The document discusses the structure and function of eukaryotic cells and their organelles. It describes the plasma membrane, mitochondria, nucleus, endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes, and cytoskeleton.
2. Key organelles include the mitochondria, which produces ATP through oxidative phosphorylation, and the nucleus, which contains DNA and directs protein synthesis.
3. The cytoskeleton is composed of microfilaments, microtubules, and intermediate filaments which help maintain cell shape and enable cell movement.
Cell movement is accomplished through the cytoskeleton, which is composed of three main types of fibers: actin filaments, microtubules, and intermediate filaments. Actin filaments interact with motor proteins like myosin to generate movement and play roles in cell adhesion, crawling, and contraction. Microtubules and their motor proteins kinesin and dynein facilitate intracellular transport and movement of cilia and flagella. Intermediate filaments provide structural support to cells but are not involved in motility. The three fiber types work together with associated proteins to control cell shape, division, transport, and movement.
The document discusses the cytoskeleton and microtubules. It defines the cytoskeleton as a network of filaments and tubules that extends throughout the cytoplasm and maintains cell shape. There are three main types of cytoskeletal filaments: microtubules, intermediate filaments, and microfilaments. Microtubules were first observed in nerve fibers in 1953. They are hollow cylindrical structures composed of tubulin protein subunits arranged in longitudinal rows. Microtubules have critical functions in cell division, intracellular transport, and formation of cilia and flagella through the action of motor proteins like kinesins and cytoplasmic dyneins.
SAI KINESIN DYENIN_611211b646114fc7ea3a61dcee56c1b4.pdfAbbireddySairam1
Title: Exploring the Microcosm: An In-depth Journey into Microbiology
Introduction:
Microbiology is a branch of biology that investigates the invisible world of microorganisms, including bacteria, viruses, fungi, and protozoa. These microscopic entities play a pivotal role in various aspects of life, from maintaining ecological balance to influencing human health and industry. This essay will delve into the diverse realms of microbiology, exploring its history, significance, key discoveries, and contemporary applications.
I. Historical Perspectives:
Microbiology has a rich history, with its roots dating back to ancient times when humans were unaware of the existence of microorganisms. The advent of the microscope in the 17th century marked a revolutionary turning point, allowing scientists like Anton van Leeuwenhoek to observe bacteria and protozoa for the first time. The germ theory of disease, proposed by Louis Pasteur and Robert Koch in the 19th century, laid the foundation for understanding the role of microorganisms in causing infections.
II. Classification of Microorganisms:
Microorganisms encompass a wide array of life forms, each with distinct characteristics and functions. Bacteria, the simplest and most abundant microorganisms, exhibit diverse shapes and metabolic pathways. Viruses, on the other hand, are intriguing entities that blur the line between living and non-living, requiring a host cell for reproduction. Fungi, including yeasts and molds, play essential roles in decomposition and various industrial processes. Protozoa, single-celled eukaryotes, contribute to ecological balance and can cause diseases in humans.
III. Significance in Ecology:
Microorganisms play a crucial role in maintaining ecological balance. Bacteria and fungi are essential for decomposing organic matter, recycling nutrients, and enriching soil fertility. Additionally, microorganisms are involved in symbiotic relationships with plants, aiding in nutrient uptake and disease resistance. In aquatic ecosystems, microbial communities are fundamental in nutrient cycling and the breakdown of pollutants.
IV. Impact on Human Health:
While some microorganisms contribute positively to human health, others pose threats as pathogens. Bacterial infections such as tuberculosis and urinary tract infections, viral diseases like influenza and COVID-19, and fungal infections are common health concerns. Microbiology has played a pivotal role in the development of antibiotics and vaccines, significantly reducing the impact of infectious diseases. However, the emergence of antibiotic-resistant strains poses ongoing challenges.
V. Industrial Applications:
Microbiology has found widespread applications in various industries. In food production, fermentation processes involving bacteria and yeast are employed to produce yogurt, cheese, beer, and bread. Microorganisms are also used in the pharmaceutical industry for the production of antibiotics, vaccines, and other therapeu
The document discusses the cytoskeleton, which provides structure and enables movement within cells. It has three main components - microfilaments, intermediate filaments, and microtubules. Microfilaments are made of actin and provide cell shape and contractility. Intermediate filaments are keratins in epithelial cells and provide structure. Microtubules originate from centrosomes and are involved in cell division and movement of organelles. The cytoskeleton also enables cell junctions and communication between cells.
(July 2016) Family-specific Kinesin Structures Reveal Neck-Linker Length Base...Logan Peter
1) The study determined crystal structures of the neck-linker and start of the coiled-coil stalk (helix α7) for kinesins from several families, including kinesin-1, -2, -5, and -7.
2) For most of the structures, the observed start of helix α7 initiating the coiled-coil stalk occurred earlier in the amino acid sequence than had been predicted.
3) This suggests that current computational methods have difficulty accurately predicting the start of coiled-coil domains. The observed neck-linker lengths differ from previous assumptions about where the neck-linker ends and coiled-coil begins.
The document discusses the roles of molecular chaperones in facilitating protein import from the cytosol into mitochondria and chloroplasts, which are double-membraned organelles. Mitochondria and chloroplasts require most of their proteins to be synthesized in the cytosol and translocated across membranes. Molecular chaperones play critical roles in ensuring these imported proteins fold properly and are directed to their correct destinations utilizing transport complexes and channels. Tight coordination is needed for the biogenesis and maintenance of mitochondria and chloroplasts given the numerous compartments and energetic barriers involved in protein transcription, translation and import.
The plasma membrane is approximately 7.5 nm thick and consists of a lipid bilayer containing proteins. The lipid bilayer forms two leaflets and houses integral and peripheral membrane proteins. It maintains cell structure, acts as a semipermeable barrier, and participates in signal transduction. The membrane regulates interactions between the cell and its environment through transporters and channels that facilitate the passage of molecules into and out of the cell.
The document discusses the cytoskeleton and its role in cell structure and movement. It contains several figures showing microscopy images of cells and their cytoskeletal components. Figure 16-10 shows microscopy images of a migratory fish cell called a keratocyte, which moves rapidly due to its large lamellipodium filled with actin filaments. The actin is responsible for the cell's movement, while microtubules and intermediate filaments are restricted to the area near the nucleus. Other figures show fluorescence microscopy images of fibroblasts, illustrating actin bundles in lamellipodia and stress fibers in the cell body.
Histochemical methods identify chemicals in cells and tissues through staining reactions. Proteins can be separated based on properties like charge, size, and binding affinity through techniques like gel electrophoresis, centrifugation, and chromatography. Mass spectrometry identifies proteins by measuring peptide masses after digestion. Assays then detect and quantify isolated proteins through methods such as staining, autoradiography, antibodies, and crystallography.
1. Translation is the process by which the genetic code in mRNA is used to synthesize polypeptide chains through the catalysis of ribosomes.
2. Ribosomes contain rRNA and proteins and have three binding sites (A, P, E sites) that facilitate the joining of amino acids specified by the mRNA sequence.
3. tRNAs act as adaptors by pairing their anticodons with mRNA codons and carrying the correct amino acid to the ribosome. Wobble base pairing allows some tRNAs to bind multiple codons.
1. RNA plays many roles in cells including functioning as biological catalysts and carrying genetic information.
2. RNA is synthesized using DNA as a template through the process of transcription. In transcription, RNA polymerase binds to DNA and synthesizes RNA in a 5' to 3' direction complementary to the DNA template.
3. Transcription is regulated through the use of promoters, which are DNA sequences that signal the start of transcription, as well as other transcriptional control elements.
1. Mutations can occur through errors in DNA replication, repair, or recombination which can cause substitutions, insertions or deletions of DNA bases. Environmental mutagens like radiation and chemicals can also directly interact with DNA and cause mutations.
2. Some mutations involve changes to a single DNA base pair, while others are larger scale mutations affecting longer DNA segments. Point mutations may substitute one base for another, while insertions or deletions can disrupt the DNA reading frame.
3. Cells have mechanisms like direct repair and photoreactivation to correct some mutations, but errors in these pathways can also lead to mutations if not repaired properly.
Cell junctions are structures that allow neighboring cells to associate with each other. The three main types of cell junctions are tight junctions, adhesive junctions, and gap junctions. Adhesive junctions like desmosomes and adherens junctions link cells together and to the extracellular matrix. These junctions contain intracellular attachment proteins and transmembrane linker proteins that anchor the cells. Gap junctions allow direct communication between cells by forming channels that let small molecules pass between cells. Cell junctions play important roles in cell polarization, barrier function, and coordinated cell behavior.
Biochemical and molecular methods allow identification and analysis of macromolecules like proteins and nucleic acids. These include hybridization, separation techniques like chromatography and electrophoresis, and using restriction enzymes. Polymerase chain reaction (PCR) cloning is commonly used to amplify specific DNA regions for analysis. Northern blotting, ribonuclease protection, and reverse transcription PCR (RT-PCR) enable analysis of mRNA expression levels and localization in cells and tissues.
The document discusses various microscopy techniques used to study cells and their parts at the microscopic level. It describes light microscopes like compound, dissecting, and fluorescence microscopes. It also discusses electron microscopes like scanning and transmission electron microscopes. It explains techniques like cell fractionation, cell and tissue culture, laser capture microdissection, and microscopy that allow isolation and study of individual cells and organelles.
This document outlines the course content for a cell biology course. It covers 10 main topics: introduction to cells, chemical foundations, methods of studying cells, genetic mechanisms, cell signaling, cell membranes and architecture, energetics, cellular traffic, cell birth/lineage/death, and the molecular basis of cancer. The course will involve seminar presentations by students on each topic, along with exams to assess comprehension. Overall, the course provides an introduction to the key concepts and components of cell biology from a biochemical and genetic perspective.
The document summarizes key aspects of the cytoskeleton, focusing on actin filaments. It describes how actin filaments: 1) maintain cell shape and generate force for cell movements through polymerization and depolymerization; 2) integrate cells through attachments to cell adhesions; and 3) produce movements within cells and at the cell membrane through interactions with myosin motor proteins. Accessory proteins regulate actin dynamics by capping, bundling, severing, and crosslinking filaments.
Receptor molecules have three domains: an extracellular ligand-binding domain, a transmembrane domain, and a cytoplasmic domain. G-protein coupled receptors have seven transmembrane alpha helices and activate intracellular signaling pathways by coupling to heterotrimeric G proteins. When a ligand binds to the receptor, it causes a G protein's alpha subunit to exchange GDP for GTP and dissociate from the beta-gamma subunits to activate downstream effector molecules like adenylyl cyclase or phospholipase C. These effectors generate second messengers such as cAMP or IP3/DAG to amplify the signal and regulate cellular processes.
The document summarizes key components of the extracellular matrix (ECM). It describes three main classes of ECM molecules: structural proteins like collagen and elastin that provide structure, proteoglycans that embed the structural proteins, and adhesive glycoproteins like fibronectin and laminin that attach cells to the matrix. It provides details on the composition, structure and function of proteoglycans, collagen, elastic fibers, reticular fibers and adhesive glycoproteins. It also discusses how defects in ECM synthesis can lead to diseases and conditions like muscular dystrophy.
This document discusses cell signaling systems. It describes how signal reception and transduction are key events in cell communication. The main components of a signaling system are ligands, which bind to receptors and provide signals to cells, and receptors, which are proteins that receive ligands and activate intracellular signaling pathways. When ligands bind to receptors, they trigger cascades of intracellular signaling proteins that alter target proteins and change cell behavior. Different cell types possess different receptors and signaling pathways, allowing cells to have specialized responses to signals.
This document summarizes several major families of cell adhesion molecules (CAMs) and adhesion receptors. It discusses cadherins, which form homophilic bonds between adjacent cells and link to the cytoskeleton. Neural cell adhesion molecules are also described, which mediate cell-cell recognition and adhesion through carbohydrate groups. Integrins are introduced as heterodimeric receptors that bind extracellular matrix proteins and link the cytoskeleton. Selectins are mentioned as facilitating leukocyte adhesion through carbohydrate binding during inflammation.
Tommy was born small and had frequent illnesses as a child. He remained short as an adult and was diagnosed with intestinal cancer at age 22. Additional unrelated tumors appeared over the next 10 years. Testing revealed Tommy had Bloom syndrome, a rare genetic disorder characterized by short stature, facial rashes from sun exposure, small head size, and high risk of multiple cancers. Bloom syndrome results from a defective gene that encodes a DNA helicase enzyme, causing errors in DNA replication and increased mutations.
The linear sequence of amino acids folds into secondary and tertiary protein structures. Proteins perform functions through binding interactions and conformational changes in their properly folded structure. Molecular chaperones assist in protein folding, preventing misfolding and aggregation. Misfolded proteins are associated with diseases like Alzheimer's and prion diseases.
Different cell types contain the same DNA but express different genes and proteins. Gene expression can be regulated at many steps from DNA to RNA to protein. Prokaryotes regulate gene expression through operons, where genes are organized together and transcribed as a single unit. The lac and trp operons are regulated by repressor proteins that bind to operator sites on the DNA and block transcription in the presence of effector molecules like lactose or tryptophan. This document discusses the mechanisms of repression and induction of the lac and trp operons through repressor proteins and RNA polymerase binding.
The document discusses gene regulation in eukaryotic cells at multiple levels, including the genome, transcription, RNA processing, translation, and post-translational modification. It provides details on mechanisms that control gene expression, such as chromatin remodeling, DNA methylation, histone modification, and the roles of enhancers and transcription factors. Gene expression patterns differ between cell types due to differential regulation of specific gene sets in each tissue.
DNA is the genetic material found in the nucleus of eukaryotic cells and in the chromosomes of prokaryotes. It exists in several forms, including linear chromosomes in eukaryotes and circular chromosomes in prokaryotes and organelles. DNA is made up of a double helix structure stabilized by hydrogen bonding between complementary nucleotide base pairs. The structure of DNA allows it to efficiently store and transmit genetic information.
1. Fred Griffith discovered that a substance present in the virulent S strain of Streptococcus pneumoniae could permanently transform the nonlethal R strain into the deadly S strain.
2. Avery, MacLeod, and McCarty identified this "transforming principle" as DNA, providing the first evidence that DNA serves as the genetic material.
3. Hershey and Chase used radioactively labeled proteins and DNA from T2 viruses to infect E. coli cells. They found that most of the radioactively labeled DNA entered the bacterial cells while most of the labeled proteins remained outside, demonstrating that the genetic material of viruses is DNA rather than protein.
This document discusses cell signaling systems. It describes how cell communication begins with a receptor protein receiving an extracellular signal and converting it into an intracellular signal. It then outlines the main components of a signaling system, including ligands, receptors, and signal transduction pathways. It provides examples of different types of ligands and receptors, and how signals are transmitted and integrated within cells. Various signaling molecules and mechanisms are examined in detail, such as calcium signaling, growth factors, hormones, neurotransmitters, and nitric oxide. The roles of cell signaling in processes like fertilization, apoptosis, and embryonic development are also summarized.
Let's Integrate MuleSoft RPA, COMPOSER, APM with AWS IDP along with Slackshyamraj55
Discover the seamless integration of RPA (Robotic Process Automation), COMPOSER, and APM with AWS IDP enhanced with Slack notifications. Explore how these technologies converge to streamline workflows, optimize performance, and ensure secure access, all while leveraging the power of AWS IDP and real-time communication via Slack notifications.
GraphSummit Singapore | The Art of the Possible with Graph - Q2 2024Neo4j
Neha Bajwa, Vice President of Product Marketing, Neo4j
Join us as we explore breakthrough innovations enabled by interconnected data and AI. Discover firsthand how organizations use relationships in data to uncover contextual insights and solve our most pressing challenges – from optimizing supply chains, detecting fraud, and improving customer experiences to accelerating drug discoveries.
Pushing the limits of ePRTC: 100ns holdover for 100 daysAdtran
At WSTS 2024, Alon Stern explored the topic of parametric holdover and explained how recent research findings can be implemented in real-world PNT networks to achieve 100 nanoseconds of accuracy for up to 100 days.
GraphSummit Singapore | The Future of Agility: Supercharging Digital Transfor...Neo4j
Leonard Jayamohan, Partner & Generative AI Lead, Deloitte
This keynote will reveal how Deloitte leverages Neo4j’s graph power for groundbreaking digital twin solutions, achieving a staggering 100x performance boost. Discover the essential role knowledge graphs play in successful generative AI implementations. Plus, get an exclusive look at an innovative Neo4j + Generative AI solution Deloitte is developing in-house.
“An Outlook of the Ongoing and Future Relationship between Blockchain Technologies and Process-aware Information Systems.” Invited talk at the joint workshop on Blockchain for Information Systems (BC4IS) and Blockchain for Trusted Data Sharing (B4TDS), co-located with with the 36th International Conference on Advanced Information Systems Engineering (CAiSE), 3 June 2024, Limassol, Cyprus.
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
Unlocking Productivity: Leveraging the Potential of Copilot in Microsoft 365, a presentation by Christoforos Vlachos, Senior Solutions Manager – Modern Workplace, Uni Systems
Sudheer Mechineni, Head of Application Frameworks, Standard Chartered Bank
Discover how Standard Chartered Bank harnessed the power of Neo4j to transform complex data access challenges into a dynamic, scalable graph database solution. This keynote will cover their journey from initial adoption to deploying a fully automated, enterprise-grade causal cluster, highlighting key strategies for modelling organisational changes and ensuring robust disaster recovery. Learn how these innovations have not only enhanced Standard Chartered Bank’s data infrastructure but also positioned them as pioneers in the banking sector’s adoption of graph technology.
Goodbye Windows 11: Make Way for Nitrux Linux 3.5.0!SOFTTECHHUB
As the digital landscape continually evolves, operating systems play a critical role in shaping user experiences and productivity. The launch of Nitrux Linux 3.5.0 marks a significant milestone, offering a robust alternative to traditional systems such as Windows 11. This article delves into the essence of Nitrux Linux 3.5.0, exploring its unique features, advantages, and how it stands as a compelling choice for both casual users and tech enthusiasts.
Enchancing adoption of Open Source Libraries. A case study on Albumentations.AIVladimir Iglovikov, Ph.D.
Presented by Vladimir Iglovikov:
- https://www.linkedin.com/in/iglovikov/
- https://x.com/viglovikov
- https://www.instagram.com/ternaus/
This presentation delves into the journey of Albumentations.ai, a highly successful open-source library for data augmentation.
Created out of a necessity for superior performance in Kaggle competitions, Albumentations has grown to become a widely used tool among data scientists and machine learning practitioners.
This case study covers various aspects, including:
People: The contributors and community that have supported Albumentations.
Metrics: The success indicators such as downloads, daily active users, GitHub stars, and financial contributions.
Challenges: The hurdles in monetizing open-source projects and measuring user engagement.
Development Practices: Best practices for creating, maintaining, and scaling open-source libraries, including code hygiene, CI/CD, and fast iteration.
Community Building: Strategies for making adoption easy, iterating quickly, and fostering a vibrant, engaged community.
Marketing: Both online and offline marketing tactics, focusing on real, impactful interactions and collaborations.
Mental Health: Maintaining balance and not feeling pressured by user demands.
Key insights include the importance of automation, making the adoption process seamless, and leveraging offline interactions for marketing. The presentation also emphasizes the need for continuous small improvements and building a friendly, inclusive community that contributes to the project's growth.
Vladimir Iglovikov brings his extensive experience as a Kaggle Grandmaster, ex-Staff ML Engineer at Lyft, sharing valuable lessons and practical advice for anyone looking to enhance the adoption of their open-source projects.
Explore more about Albumentations and join the community at:
GitHub: https://github.com/albumentations-team/albumentations
Website: https://albumentations.ai/
LinkedIn: https://www.linkedin.com/company/100504475
Twitter: https://x.com/albumentations
TrustArc Webinar - 2024 Global Privacy SurveyTrustArc
How does your privacy program stack up against your peers? What challenges are privacy teams tackling and prioritizing in 2024?
In the fifth annual Global Privacy Benchmarks Survey, we asked over 1,800 global privacy professionals and business executives to share their perspectives on the current state of privacy inside and outside of their organizations. This year’s report focused on emerging areas of importance for privacy and compliance professionals, including considerations and implications of Artificial Intelligence (AI) technologies, building brand trust, and different approaches for achieving higher privacy competence scores.
See how organizational priorities and strategic approaches to data security and privacy are evolving around the globe.
This webinar will review:
- The top 10 privacy insights from the fifth annual Global Privacy Benchmarks Survey
- The top challenges for privacy leaders, practitioners, and organizations in 2024
- Key themes to consider in developing and maintaining your privacy program
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
In this session I delve into the encryption technology used in Microsoft 365 and Microsoft Purview. Including the concepts of Customer Key and Double Key Encryption.
Communications Mining Series - Zero to Hero - Session 1DianaGray10
This session provides introduction to UiPath Communication Mining, importance and platform overview. You will acquire a good understand of the phases in Communication Mining as we go over the platform with you. Topics covered:
• Communication Mining Overview
• Why is it important?
• How can it help today’s business and the benefits
• Phases in Communication Mining
• Demo on Platform overview
• Q/A
Maruthi Prithivirajan, Head of ASEAN & IN Solution Architecture, Neo4j
Get an inside look at the latest Neo4j innovations that enable relationship-driven intelligence at scale. Learn more about the newest cloud integrations and product enhancements that make Neo4j an essential choice for developers building apps with interconnected data and generative AI.
Cosa hanno in comune un mattoncino Lego e la backdoor XZ?Speck&Tech
ABSTRACT: A prima vista, un mattoncino Lego e la backdoor XZ potrebbero avere in comune il fatto di essere entrambi blocchi di costruzione, o dipendenze di progetti creativi e software. La realtà è che un mattoncino Lego e il caso della backdoor XZ hanno molto di più di tutto ciò in comune.
Partecipate alla presentazione per immergervi in una storia di interoperabilità, standard e formati aperti, per poi discutere del ruolo importante che i contributori hanno in una comunità open source sostenibile.
BIO: Sostenitrice del software libero e dei formati standard e aperti. È stata un membro attivo dei progetti Fedora e openSUSE e ha co-fondato l'Associazione LibreItalia dove è stata coinvolta in diversi eventi, migrazioni e formazione relativi a LibreOffice. In precedenza ha lavorato a migrazioni e corsi di formazione su LibreOffice per diverse amministrazioni pubbliche e privati. Da gennaio 2020 lavora in SUSE come Software Release Engineer per Uyuni e SUSE Manager e quando non segue la sua passione per i computer e per Geeko coltiva la sua curiosità per l'astronomia (da cui deriva il suo nickname deneb_alpha).
Cosa hanno in comune un mattoncino Lego e la backdoor XZ?
Microtubules and molecular motors
1.
2. Serve as cytoskeleton to maintain cell shape
Involved in changes in cell shape, & serve as a
"temporary scaffolding" for other organelles.
They function as diffusion channels for water and
metabolites and even macromolecules, thus aiding
intracellular transport.
In mitosis, microtubules form the mitotic spindle along
which chromosomes move.
Some cellular proteins act to disassemble microtubules,
either by severing microtubules or by increasing the rate
of tubulin depolymerization from microtubule ends.
Other proteins (called microtubule-associated proteins
or MAPs) bind to microtubules and increase their
stability.
Such interactions allow the cell to stabilize microtubules
in particular locations and provide an important
mechanism for determining cell shape and polarity.
3. MICROTUBULES
Microtubules, like actin microfilaments, exhibit both
structural and functional polarity.
Dimeric αβ–tubulin subunits interact end-to-end to form
protofilaments, which associate laterally into
microtubules.
The wall is composed of 13 protofilaments of the
protein tubulin, and later bind to microtubule-
associated proteins (MAPs).
4. A stabilizing MAP consists of a basic microtubule-binding domain and an acidic
projection domain. The projection domain can bind to membranes, intermediate
filaments, or other microtubules, and its length controls how far apart
microtubules are spaced. The microtubule-binding domain contains repeats of a
conserved, positively charged 4-residue amino acid sequence that binds the
negatively charged C-terminal part of tubulin, thereby stabilizing the polymer.
5. The structure of a microtubule and its subunit. (A) The subunit of each
protofilament is a tubulin heterodimer, formed from a very tightly linked
pair of α- and β-tubulin monomers. The GTP molecule in the β-tubulin
monomer is less tightly bound and has an important role in filament
dynamics. Both nucleotides are shown in red. (B) One tubulin subunit (α-β
heterodimer) and one protofilament consist of many adjacent subunits
with the same orientation. (C) The microtubule is a stiff hollow tube formed
from 13 protofilaments aligned in parallel. (D) A short segment of a
microtubule viewed in an EM. (E) EM of a cross section of a microtubule.
6. Unlike microfilaments, micro-
tubules are non-contractile
polarized structures with a (-)
end anchored to the centro-
some, and a free (+) end at
which tubulin monomers are
added or removed.
They exhibit : (1) treadmilling,
the addition of subunits at one
end and their loss at the other
end, and (2) dynamic
instability, the oscillation
between growth and
shrinkage.
Balance depends on whether
the exchangeable GTP bound
to β-tubulin is present on the
(+) end or whether it has been
hydrolyzed to GDP.
7. Stages in assembly of
microtubules.
Free tubulin dimers form
short, unstable
protofilaments (1), which
then form more stable
curved sheets (2). A
sheet wraps around into
a microtubule with 13
protofilaments. The
microtubule then grows
by the addition of
subunits (3).The free
tubulin dimers have GTP
(red dot) bound to the
exchangeable nucleotide-
binding site on the β-
tubulin monomer. After If the rate of polymerization is faster than the
incorporation of a rate of GTP hydrolysis, then a cap of GTP-
dimeric subunit into a bound subunits is generated at the (+) end,
microtubule, the GTP on although the bulk of β-tubulin in a microtubule
the β-tubulin is will contain GDP. The rate of polymerization is
hydrolyzed to GDP. twice as fast at the (+) end as at the (-) end.
8. Dynamic instability model
of microtubule growth and shrinkage.
Only microtubules
whose (+) ends are
associated with GTP-
tubulin (those with a GTP
cap) are stable and can
serve as primers for the
polymerization of
tubulin. Microtubules
with GDP-tubulin (blue)
at the (+) end, or those
with a GDP cap are
rapidly depolymerized
and may disappear
within 1 min. Because
the GDP cap is unstable,
the microtubule end
peels apart to release
tubulin subunits.
9. Microtubules (blue)
organized around
the MTOC and spindle
poles (1) establish an
internal polarity to
movements and
structures in the
interphase cell (left)
and the mitotic cell
(right). Assembly and
disassembly (2) cause
microtubules to probe
the cell cytoplasm and
are harnessed at
mitosis to move
chromosomes. Long-
distance movement of
vesicles are powered
by kinesin and dynein
motors. Both motors
are critical in the
assembly of the
spindle and the
separation of
chromosomes in
mitosis.
10. MOLECULAR MOTORS
MOTOR PROTEINS- specialized motility structures in
eukaryotic cells consisting of highly ordered arrays of
motor proteins that move on stabilized filament tracks.
They use the energy of ATP hydrolysis to move along
microtubules or actin filaments.
They mediate the sliding of filaments relative to one
another and the transport of membrane-enclosed
organelles along filament tracks.
11. Motor
proteins pull
components
of the cyto-
skeleton
past each
other.
Motor molecules
also carry vesicles
or organelles to
various
destinations along
“monorails’
provided by the
cytoskeleton.
12. All known motor proteins that move on actin
filaments are members of the myosin superfamily.
Motor proteins that move on microtubules are
members of either the kinesin superfamily or the
dynein family.
The myosin and kinesin superfamilies are diverse,
with about 40 genes encoding each type of
protein in humans.
The only structural element shared among all
members of each superfamily is the motor "head"
domain. These heads can be attached to a wide
variety of "tails," which attach to different types
of cargo and enable the various family members
to perform different functions in the cell.
13.
14. Functions of myosin tail domains.
(a) Myosin I and myosin V are localized to cellular membranes by
undetermined sites in their tail domains. As a result, these
myosins are associated with intracellular membrane vesicles or
the cytoplasmic face of the plasma membrane. (b) In contrast,
the coiled-coil tail domains of myosin II molecules pack side by
side, forming a thick filament from which the heads project. In a
skeletal muscle, the thick filament is bipolar. Heads are at the
ends of the thick filament and are separated by a bare zone,
which consists of the side-by-side tails.
16. Summary of the coupling between ATP hydrolysis and conformational
changes for myosin II. Myosin begins its cycle tightly bound to the actin
filament, with no associated nucleotide, the so-called "rigor" state. ATP
binding releases the head from the filament. ATP hydrolysis occurs while
the myosin head is detached from the filament, causing the head to
assume a cocked conformation, although both ADP and inorganic
phosphate remain tightly bound to the head. When the head rebinds to the
filament, the release of phosphate, followed by the release of ADP, trigger
the power stroke that moves the filament relative to the motor protein. ATP
binding releases the head to allow the cycle to begin again. In the myosin
cycle, the head remains bound to the actin filament for only about 5% of
the entire cycle time, allowing many myosins to work together to move a
single actin filament.
17.
18. KINESINS move towards the (+) ends of tubules,
while dyneins move towards the (–) ends.
Kinesin is responsible for movement of vesicles
and organelles in the cytoplasm, dynein regulates
2-way traffic and dynamin serves as a motor for
sliding movements during microtubule elongation.
19. Kinesin and kinesin-related proteins. (A) Structures of four kinesin
superfamily members. Conventional kinesin has the motor domain at
the N-terminus of the heavy chain. The middle domain forms a long
coiled coil, mediating dimerization. The C-terminal domain forms a
tail that attaches to cargo, such as a membrane-enclosed organelle.
These kinesins generally travel toward the minus end instead of the
plus end of a microtubule. (B) Freeze-etch EM of a kinesin molecule
with the head domains on the left.
20. Summary of the coupling between ATP hydrolysis and conformational
changes for kinesin. At the start of the cycle, one of the two kinesin
heads, the front or leading head (dark green) is bound to the microtubule,
with the rear or trailing head (light green) detached. Binding of ATP to the
front head causes the rear head to be thrown forward, past the binding
site of the attached head, to another binding site further toward the plus
end of the microtubule. Release of ADP from the second head (now in the
front) and hydrolysis of ATP on the first head (now in the rear) brings the
dimer back to the original state, but the two heads have switched their
relative positions, and the motor protein has moved one step along the
microtubule protofilament. In this cycle, each head spends about 50% of
its time attached to the microtubule and 50% of its time detached.
21. CENTROSOME
Also called the centrosphere or cell center, which
refers to a specialized zone of cytoplasm containing
the centrioles and a variable number of small dense
bodies called centriolar satellites.
Considered to be a center of activities associated
with cell division, usually adjacent to the nucleus.
The Golgi apparatus often partially surrounds the
centrosome on the side away from the nucleus.
It consists of an amorphous matrix of protein
containing the g-tubulin ring complexes that nucleate
microtubule growth.
They serve as basal bodies and sites of anchor for
epithelial cilia.
Plant and fungal cells have a structure equivalent to a
centrosome, although they do not contain centrioles .
22. The matrix of the centrosome
is organized by a pair of
centrioles.
An electron micrograph of a
thick section of a centrosome
showing an end-on view of a
centriole. The ring of modified
microtubules of the centriole
is visible, surrounded by the
fibrous centrosome matrix.
23. Centrioles are self-duplicating organelles that exhibit
continuity from one cell generation to the next. They
double in number immediately before cell division but they
do not undergo transverse fission.
Paired centrioles are called diplosome. The long axes of
the two centrioles are usually perpendicular to each other.
Centrioles become prominent in mitosis. In prophase they
separate and a new procentriole develops adjacent to
each.
Microtubule organizing centers (MTOCs) become
nucleation sites around each centriole to form the fibers of
the aster and the mitotic spindle.
MTOCs determine cell polarity including the organization
of cell organelles, direction of membrane trafficking, and
orientation of microtubules.
Because microtubule assembly is nucleated from MTOCs,
the (-) end of most microtubules is adjacent to the MTOC
and the (+) end is distal.
24. A centrosome with
attached
microtubules. The
minus end of each
microtubule is
embedded in the
centrosome, having
grown from a Ý-
tubulin ring
complex, whereas
the plus end of
each microtubule is
free in the
cytoplasm.
25. In EM, each centriole
is found to be a hollow
cylinder closed at one
end and open at the
other.
The central cavity is
occupied by small
dense granules.
In transverse section,
its wall is composed of
9 evenly spaced triplet
microtubules (9 x 3).
Each triplet (A, B and C) is set at an angle of about
400o to its respective tangent.
Subunit A is nearest to the centriole axis; short fibers
connect it to subunit C of the adjacent triplet.
26. Orientation of cellular
microtubules.
(a) In interphase animal cells, the
(-) ends of most microtubules are
proximal to the MTOC. Similarly, the
microtubules in flagella and cilia
have their (-) ends continuous with
the basal body, which acts as the
MTOC for these structures.
(b) As cells enter mitosis, the
microtubule network rearranges,
forming a mitotic spindle. The (-)
ends of all spindle microtubules
point toward one of the two
MTOCs, or poles, as they are called
in mitotic cells. (c) In nerve cells,
the (-) ends of all axonal
microtubules are oriented toward
the base of the axon, but dendritic
microtubules have mixed polarities.
27. The restructuring of the microtubule cytoskeleton is
directed by duplication of the centrosome to form two
separate MTOCs at opposite poles of the mitotic spindle.
The centrioles and other components of the centrosome
are duplicated in interphase cells, but they remain together
on one side of the nucleus until the beginning of mitosis.
The two centrosomes then separate and move to opposite
sides of the nucleus, forming the two poles of the mitotic
spindle.
As the cell enters mitosis, the dynamics of microtubule
assembly and disassembly also change dramatically.
First, the rate of microtubule disassembly increases about
tenfold, resulting in overall depolymerization and shrinkage
of microtubules.
At the same time, the number of microtubules emanating
from the centrosome increases by five- to tenfold.
28. In combination, these changes result in disassembly of
the interphase microtubules and the outgrowth of large
numbers of short microtubules from the centrosomes.
As mitosis proceeds, the two chromatids of each
chromosome are then pulled to opposite poles of the
spindle. This chromosome movement is mediated by
motor proteins associated with the spindle microtubules.
In the final stage of mitosis, nuclear envelopes reform, the
chromosomes decondense, and cytokinesis takes place.
After cell division, each cell acquires 2 centrioles, one
from the parent cell, and one which arose as a
procentriole.
If mitotic cells are exposed to drugs like colchicine (binds
to monomeric tubulin and prevent polymerization),
vinblastine and taxol (disrupt microtubule dynamics),
microtubules disappear and mitosis is arrested because
of inadequate formation of the mitotic spindle. These
drugs are useful in the treatment of certain cancers.
29. Effect of the drug taxol on microtubule organization.
(A) Molecular structure of taxol. Recently, organic chemists have
succeeded in synthesizing this complex molecule, which is widely used for
cancer treatment. (B) Immunofluorescence micrograph showing the
microtubule organization in a liver epithelial cell before the addition of
taxol. (C) Microtubule organization in the same type of cell after taxol
treatment. Note the thick circumferential bundles of microtubules around
the periphery of the cell. (D) A Pacific yew tree, the natural source of taxol.
30. CILIA & FLAGELLA
Characteristic 9 x 2
arrangement of
microtubules
Tubulin forms doublets
composed of subunit A, a
complete microtubule
with 13 protofilaments,
joined to a C-shaped
subunit B with only 10.
Lateral arms composed of
the MAP axonemal dynein
project from subunit A to
subunit B of the next.
Major motor portion of the
flagellum is called the
axoneme.
31.
32. Ciliary dynein is a large motor protein assembly composed of 9-12
polypeptide chains (A) The heavy chains form the major portion of the
globular head & stem domains, & many of the smaller chains are
clustered around the base of the stem. The base of the molecule binds
tightly to an A microtubule in an ATP-independent manner, while the
large globular heads have an ATP-dependent binding site for a B
microtubule. When the heads hydrolyze their bound ATP, they move
toward the (-) end of the B microtubule, thereby producing a sliding
force between the adjacent microtubule doublets in a cilium or
flagellum. (B) Freeze-etch EM of a cilium showing the dynein arms
projecting at regular intervals from the doublet microtubules
33. The bending of an axoneme.
(A) When axonemes are exposed to the proteolytic enzyme trypsin, the
linkages holding neighboring doublet microtubules together are broken.
Addition of ATP allows the motor action of the dynein heads to slide one
pair of doublet microtubules against the other pair. (B) In an intact
axoneme (such as in a sperm), sliding of the doublet microtubules is
prevented by flexible protein links. The motor action therefore causes a
bending motion, creating waves or beating motions
34. The contrasting motions of flagella
and cilia. (A) The wavelike motion of
the flagellum of a sperm cell. Waves
of constant amplitude move
continuously from the base to the tip
of the flagellum. (B) The beat of a
cilium, which resembles the breast
stroke in swimming.