KEY CONCEPTS
6.1 Biologists use microscopes and the tools of biochemistry to
study cells
6.2 Eukaryotic cells have internal membranes that
compartmentalize their functions
6.3 The eukaryotic cell’s genetic instructions are housed in the nucleus and carried out by the ribosomes
6.4 The endomembrane system regulates protein traffic and
performs metabolic functions in the cell
6.5 Mitochondria and chloroplasts change energy from one form to another
6.6 The cytoskeleton is a network of fibers that organizes structures and activities in the cell
6.7 Extracellular components and connections between cells help coordinate cellular activities
The document provides an overview of metabolism and energy transformations in cells. It discusses how (1) cells extract and use energy to perform work through thousands of chemical reactions organized into metabolic pathways, (2) the laws of thermodynamics govern energy transformations with energy being conserved but entropy increasing, and (3) ATP powers cellular work by coupling exergonic reactions like its hydrolysis to endergonic reactions like transport or synthesis through energy transfer.
The document provides an overview of cell communication and signaling. It discusses:
- Cells communicate via chemical signals such as epinephrine.
- Signal transduction pathways convert signals at the cell surface into responses.
- Reception involves signal molecules binding receptors, transduction uses cascades of molecular interactions to relay signals from receptors to target molecules, and response leads to activation of cellular responses.
- Common mechanisms of signaling include G-protein coupled receptors, receptor tyrosine kinases, calcium ions, cyclic AMP, and inositol triphosphate.
The document summarizes key concepts about the cell cycle and cell division. It discusses how cell division allows for reproduction, growth, and repair. There are two main types of cell division - mitosis, which produces genetically identical daughter cells, and meiosis, which produces gametes. The cell cycle consists of interphase and the mitotic phase. Interphase includes DNA replication in S phase. Mitosis separates duplicated chromosomes into two daughter cells. Cytokinesis then divides the cytoplasm. Prokaryotes divide by binary fission, with the chromosome replicating and daughter chromosomes moving apart.
The document summarizes key concepts about membrane structure and function from Chapter 7 of Campbell Biology. It discusses the fluid mosaic model of membrane structure, which states that membranes are made of a phospholipid bilayer with various proteins embedded within. Membranes are selectively permeable, allowing some substances to pass through via passive transport mechanisms like diffusion and facilitated diffusion. Membranes regulate the movement of substances in and out of cells.
This document provides an overview of a lecture on cell structure and function from Campbell Biology, Ninth Edition. It includes:
1) Descriptions of different microscopy techniques used to study cells, such as light microscopy, electron microscopy, and new super-resolution techniques.
2) Explanations of how cell fractionation separates cell components using centrifugation in order to determine organelle functions.
3) Comparisons of prokaryotic and eukaryotic cell structures, focusing on eukaryotic cells' internal membranes that compartmentalize functions.
The cytoskeleton consists of three main types of protein filaments - microtubules, microfilaments, and intermediate filaments. Microtubules provide structure to cells and are involved in cell motility and intracellular transport. Microfilaments are the thinnest filaments and are involved in cell movement and cytoplasmic streaming. Intermediate filaments provide structural support and help maintain cell shape.
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.
B.Sc. Biochemistry II Cellular Biochemistry Unit 3 Cell CycleRai University
The document discusses the cell cycle and cell division. It begins by explaining that all cells come from pre-existing cells and that cells divide through mitosis or binary fission to grow, repair damage, or replace old cells. The cell cycle consists of interphase, where the cell grows and DNA replicates, and mitosis, where the cell divides. Meiosis produces gametes through two cell divisions and results in four haploid cells rather than two identical diploid cells as in mitosis. The key stages and purposes of the cell cycle, mitosis, and meiosis are summarized.
The document provides an overview of metabolism and energy transformations in cells. It discusses how (1) cells extract and use energy to perform work through thousands of chemical reactions organized into metabolic pathways, (2) the laws of thermodynamics govern energy transformations with energy being conserved but entropy increasing, and (3) ATP powers cellular work by coupling exergonic reactions like its hydrolysis to endergonic reactions like transport or synthesis through energy transfer.
The document provides an overview of cell communication and signaling. It discusses:
- Cells communicate via chemical signals such as epinephrine.
- Signal transduction pathways convert signals at the cell surface into responses.
- Reception involves signal molecules binding receptors, transduction uses cascades of molecular interactions to relay signals from receptors to target molecules, and response leads to activation of cellular responses.
- Common mechanisms of signaling include G-protein coupled receptors, receptor tyrosine kinases, calcium ions, cyclic AMP, and inositol triphosphate.
The document summarizes key concepts about the cell cycle and cell division. It discusses how cell division allows for reproduction, growth, and repair. There are two main types of cell division - mitosis, which produces genetically identical daughter cells, and meiosis, which produces gametes. The cell cycle consists of interphase and the mitotic phase. Interphase includes DNA replication in S phase. Mitosis separates duplicated chromosomes into two daughter cells. Cytokinesis then divides the cytoplasm. Prokaryotes divide by binary fission, with the chromosome replicating and daughter chromosomes moving apart.
The document summarizes key concepts about membrane structure and function from Chapter 7 of Campbell Biology. It discusses the fluid mosaic model of membrane structure, which states that membranes are made of a phospholipid bilayer with various proteins embedded within. Membranes are selectively permeable, allowing some substances to pass through via passive transport mechanisms like diffusion and facilitated diffusion. Membranes regulate the movement of substances in and out of cells.
This document provides an overview of a lecture on cell structure and function from Campbell Biology, Ninth Edition. It includes:
1) Descriptions of different microscopy techniques used to study cells, such as light microscopy, electron microscopy, and new super-resolution techniques.
2) Explanations of how cell fractionation separates cell components using centrifugation in order to determine organelle functions.
3) Comparisons of prokaryotic and eukaryotic cell structures, focusing on eukaryotic cells' internal membranes that compartmentalize functions.
The cytoskeleton consists of three main types of protein filaments - microtubules, microfilaments, and intermediate filaments. Microtubules provide structure to cells and are involved in cell motility and intracellular transport. Microfilaments are the thinnest filaments and are involved in cell movement and cytoplasmic streaming. Intermediate filaments provide structural support and help maintain cell shape.
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.
B.Sc. Biochemistry II Cellular Biochemistry Unit 3 Cell CycleRai University
The document discusses the cell cycle and cell division. It begins by explaining that all cells come from pre-existing cells and that cells divide through mitosis or binary fission to grow, repair damage, or replace old cells. The cell cycle consists of interphase, where the cell grows and DNA replicates, and mitosis, where the cell divides. Meiosis produces gametes through two cell divisions and results in four haploid cells rather than two identical diploid cells as in mitosis. The key stages and purposes of the cell cycle, mitosis, and meiosis are summarized.
6.1 Biologists use microscopes and the tools of biochemistry to study cells
6.2 Eukaryotic cells have internal membranes that compartmentalize their functions.
6.3 The eukaryotic cell's genetic instructions are housed in the nucleus and carried out by the ribosomes.
6.4 The endomembrane system regulates protein traffic and performs metabolic functions in the cell.
6.5 Mitochondria and chloroplasts change energy from one form to another.
6.6 The cyto
The cytoskeleton is composed of microtubules, microfilaments, and intermediate filaments that help maintain cell shape and enable cell movement. Microtubules are involved in cell division, shape, and organelle movement. Microfilaments assist with cell division, shape changes, muscle contraction, and motility. Intermediate filaments provide structural support and anchor organelles. Motor proteins use ATP to "walk" along cytoskeletal fibers and transport vesicles and organelles within the cell.
The plasma membrane is selectively permeable and allows some substances to pass through more easily than others. It contains phospholipids arranged in a bilayer with hydrophobic tails interacting in the middle and hydrophilic heads facing outwards. Embedded proteins can be integral and span the entire membrane or peripheral and attach to surface. The fluid mosaic model describes the membrane as a fluid structure with phospholipids and proteins able to move laterally. Transport across the membrane can be passive via diffusion, osmosis, and facilitated diffusion or active via protein pumps and requires cell energy. Endocytosis and exocytosis involve vesicle transport across the membrane.
Ch 5: The Structure and Function of Large Biological Moleculesveneethmathew
The document summarizes key concepts about large biological molecules from Chapter 5 of Campbell Biology. It discusses the four main classes of macromolecules - carbohydrates, lipids, proteins and nucleic acids. It focuses on carbohydrates and lipids, explaining that carbohydrates include sugars and polysaccharides which serve structural and storage functions, while lipids are non-polymeric and include fats, phospholipids and steroids. Specific carbohydrates and lipids are discussed such as monosaccharides, starch, cellulose and fatty acids.
1. The document discusses meiosis and sexual life cycles in biology. It provides details on the stages of meiosis, including prophase I, metaphase I, anaphase I and telophase I.
2. Meiosis results in four haploid daughter cells rather than two, and reduces the number of chromosome sets from diploid to haploid. It occurs in two divisions: meiosis I and meiosis II.
3. There are three main types of sexual life cycles that differ in the timing of meiosis and fertilization - in animals, plants and fungi. This ensures genetic variation between generations.
05 the structure and function of large biological moleculeskindarspirit
This document provides an overview of a lecture on large biological molecules. It discusses the four main classes of large molecules - carbohydrates, lipids, proteins, and nucleic acids. It focuses on the structures and functions of carbohydrates like sugars and polysaccharides, lipids like fats and phospholipids, and proteins. Carbohydrates serve roles in energy storage and structure. Lipids are hydrophobic and include fats, phospholipids, and steroids. Proteins have diverse structures allowing a wide range of functions such as structure, storage, transport, and catalysis by enzymes.
This document provides an overview of chapter 7 from Campbell Biology, which discusses membrane structure and function. It includes 3 key points:
1) Cellular membranes are fluid mosaics composed of phospholipids and membrane proteins. The fluid mosaic model describes membranes as fluid bilayers with embedded proteins.
2) Membrane proteins perform important functions like transport, signaling, and cell recognition. Integral proteins span the membrane while peripheral proteins are attached to the surface.
3) Membranes are selectively permeable, regulating the movement of substances in and out of cells. This property results from the asymmetric distribution of proteins and lipids in the membrane.
It is a process used by plants & other organisms to convert light energy into chemical energy that can be later used by organisms as a fuel. i.e; energy transformation
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 cytoskeleton is a network of protein filaments and tubules that gives cells their shape and allows them to move. It has three main components: microtubules, microfilaments, and intermediate filaments. Microtubules are hollow tubes involved in intracellular transport and cell division. Microfilaments made of actin help with cell movement and shape. Intermediate filaments provide structural support. Together, the cytoskeleton transports vesicles, separates chromosomes, allows muscle contraction, and maintains cell shape.
The document discusses the biological membrane and its chemical composition. It notes that the plasma membrane is the outer boundary of cells, consisting of a double layer of lipid molecules with embedded proteins. The major components of membranes are glycerophospholipids, sphingolipids, and cholesterol. Glycerophospholipids are amphipathic lipids that form the lipid bilayer structure. The fluid mosaic model describes membranes as a fluid structure with lipids and proteins able to move laterally. Membrane proteins can be integral or peripheral, and help with cell functions like transport and signaling. Membrane fluidity is influenced by temperature and lipid composition.
This document provides an overview of chapter 6 from Campbell Biology, 9th edition, which discusses cellular structure and function. It begins with definitions of key cellular concepts like prokaryotic and eukaryotic cells. It then summarizes the structures and functions of major cellular organelles like the nucleus, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, mitochondria, and chloroplasts. It concludes by discussing the endosymbiotic theory of how mitochondria and chloroplasts originated from engulfed bacteria within early eukaryotic cells. The document utilizes diagrams and micrographs to illustrate key cellular structures.
This document provides an overview of the cell membrane. It begins with learning outcomes which state that students will be able to demonstrate cell organelles and describe the cell membrane. The contents then outline topics on the introduction, models, structure, composition and functions of the cell membrane. Key points made include that the cell membrane is a semipermeable barrier made of proteins, lipids and carbohydrates that separates the intracellular and extracellular fluids and regulates what passes in and out of the cell. The fluid mosaic model of the cell membrane is also described.
Tiếng Anh chuyên ngành Sinh học [03 lecture presentation]Tài liệu sinh học
- Water is essential for life on Earth and makes up 70-95% of living organisms. Its unique properties like polarity and hydrogen bonding allow water to moderate temperature, act as a solvent, and more.
- The pH scale measures how acidic or basic a solution is based on hydrogen ion concentration. Most biological fluids aim to be near neutral at pH 6-8.
- Acids and bases can change the pH of an environment, affecting chemical reactions in cells. Buffers help maintain pH within a tolerable range for organisms.
This chapter discusses how gene expression is controlled at the transcriptional level. It covers the basic mechanisms that regulate when and how often genes are transcribed from DNA into messenger RNA by RNA polymerase. Key players involved in transcriptional control include transcription factors, promoters, enhancers, silencers and chromatin structure.
Cell membranes are composed of lipids (45%), proteins (45%), and carbohydrates (10%). Lipids form a bilayer with hydrophilic heads facing out and hydrophobic tails facing inward. Membrane proteins can be peripheral or integral. Peripheral proteins attach to lipid heads while integral proteins span or embed within the membrane. Together, lipids and proteins give cell membranes a fluid mosaic structure and allow them to perform important functions like selectively regulating transport into and out of the cell.
The document summarizes centrosomes and centrioles. It discusses that centrosomes are located near the nucleus and are responsible for cell division, cytokinesis, and cytoskeleton formation. Within centrosomes are centrioles, which are made up of nine groups of microtubules arranged in a ring. Centrioles play important roles in cell division through organizing the mitotic spindle, cellular organization by organizing microtubules, and formation of cilia and flagella. Centriole duplication is coupled with the cell cycle and centrosome duplication occurs in early S phase through assembly of a new procentriole next to each parental centriole.
1) The document discusses a lecture on carbon and the molecular diversity of life from Campbell Biology.
2) Carbon is able to form four bonds with other atoms, allowing it to create large, complex molecules like proteins, DNA, carbohydrates, and other molecules essential for life.
3) Key functional groups on organic molecules include hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, phosphate, and methyl groups, which influence the properties and reactions of biological compounds.
This document is a PowerPoint presentation on the functional anatomy of prokaryotic and eukaryotic cells. It compares and contrasts the structures of prokaryotic and eukaryotic cells, focusing on key differences like prokaryotes lacking a nucleus and organelles. The presentation also examines the structures of bacterial cells in more detail, including cell shape, flagella, pili, the cell wall, and plasma membrane. It describes the different types of cell walls found in bacteria and their functions.
KEY CONCEPTS
5.1 Macromolecules are polymers, built from monomers
5.2 Carbohydrates serve as fuel and building material
5.3 Lipids are a diverse group of hydrophobic molecules
5.4 Proteins include a diversity of structures, resulting in a wide range of functions
5.5 Nucleic acids store, transmit, and help express hereditary
information
5.6 Genomics and proteomics have transformed biological inquiry and applications
Chapter 16: Molecular Basis of InheritanceAngel Vega
KEY CONCEPTS
16.1 DNA is the genetic material
16.2 Many proteins work together in
DNA replication and repair
16.3 A chromosome consists of a DNA molecule packed together with proteins
6.1 Biologists use microscopes and the tools of biochemistry to study cells
6.2 Eukaryotic cells have internal membranes that compartmentalize their functions.
6.3 The eukaryotic cell's genetic instructions are housed in the nucleus and carried out by the ribosomes.
6.4 The endomembrane system regulates protein traffic and performs metabolic functions in the cell.
6.5 Mitochondria and chloroplasts change energy from one form to another.
6.6 The cyto
The cytoskeleton is composed of microtubules, microfilaments, and intermediate filaments that help maintain cell shape and enable cell movement. Microtubules are involved in cell division, shape, and organelle movement. Microfilaments assist with cell division, shape changes, muscle contraction, and motility. Intermediate filaments provide structural support and anchor organelles. Motor proteins use ATP to "walk" along cytoskeletal fibers and transport vesicles and organelles within the cell.
The plasma membrane is selectively permeable and allows some substances to pass through more easily than others. It contains phospholipids arranged in a bilayer with hydrophobic tails interacting in the middle and hydrophilic heads facing outwards. Embedded proteins can be integral and span the entire membrane or peripheral and attach to surface. The fluid mosaic model describes the membrane as a fluid structure with phospholipids and proteins able to move laterally. Transport across the membrane can be passive via diffusion, osmosis, and facilitated diffusion or active via protein pumps and requires cell energy. Endocytosis and exocytosis involve vesicle transport across the membrane.
Ch 5: The Structure and Function of Large Biological Moleculesveneethmathew
The document summarizes key concepts about large biological molecules from Chapter 5 of Campbell Biology. It discusses the four main classes of macromolecules - carbohydrates, lipids, proteins and nucleic acids. It focuses on carbohydrates and lipids, explaining that carbohydrates include sugars and polysaccharides which serve structural and storage functions, while lipids are non-polymeric and include fats, phospholipids and steroids. Specific carbohydrates and lipids are discussed such as monosaccharides, starch, cellulose and fatty acids.
1. The document discusses meiosis and sexual life cycles in biology. It provides details on the stages of meiosis, including prophase I, metaphase I, anaphase I and telophase I.
2. Meiosis results in four haploid daughter cells rather than two, and reduces the number of chromosome sets from diploid to haploid. It occurs in two divisions: meiosis I and meiosis II.
3. There are three main types of sexual life cycles that differ in the timing of meiosis and fertilization - in animals, plants and fungi. This ensures genetic variation between generations.
05 the structure and function of large biological moleculeskindarspirit
This document provides an overview of a lecture on large biological molecules. It discusses the four main classes of large molecules - carbohydrates, lipids, proteins, and nucleic acids. It focuses on the structures and functions of carbohydrates like sugars and polysaccharides, lipids like fats and phospholipids, and proteins. Carbohydrates serve roles in energy storage and structure. Lipids are hydrophobic and include fats, phospholipids, and steroids. Proteins have diverse structures allowing a wide range of functions such as structure, storage, transport, and catalysis by enzymes.
This document provides an overview of chapter 7 from Campbell Biology, which discusses membrane structure and function. It includes 3 key points:
1) Cellular membranes are fluid mosaics composed of phospholipids and membrane proteins. The fluid mosaic model describes membranes as fluid bilayers with embedded proteins.
2) Membrane proteins perform important functions like transport, signaling, and cell recognition. Integral proteins span the membrane while peripheral proteins are attached to the surface.
3) Membranes are selectively permeable, regulating the movement of substances in and out of cells. This property results from the asymmetric distribution of proteins and lipids in the membrane.
It is a process used by plants & other organisms to convert light energy into chemical energy that can be later used by organisms as a fuel. i.e; energy transformation
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 cytoskeleton is a network of protein filaments and tubules that gives cells their shape and allows them to move. It has three main components: microtubules, microfilaments, and intermediate filaments. Microtubules are hollow tubes involved in intracellular transport and cell division. Microfilaments made of actin help with cell movement and shape. Intermediate filaments provide structural support. Together, the cytoskeleton transports vesicles, separates chromosomes, allows muscle contraction, and maintains cell shape.
The document discusses the biological membrane and its chemical composition. It notes that the plasma membrane is the outer boundary of cells, consisting of a double layer of lipid molecules with embedded proteins. The major components of membranes are glycerophospholipids, sphingolipids, and cholesterol. Glycerophospholipids are amphipathic lipids that form the lipid bilayer structure. The fluid mosaic model describes membranes as a fluid structure with lipids and proteins able to move laterally. Membrane proteins can be integral or peripheral, and help with cell functions like transport and signaling. Membrane fluidity is influenced by temperature and lipid composition.
This document provides an overview of chapter 6 from Campbell Biology, 9th edition, which discusses cellular structure and function. It begins with definitions of key cellular concepts like prokaryotic and eukaryotic cells. It then summarizes the structures and functions of major cellular organelles like the nucleus, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, mitochondria, and chloroplasts. It concludes by discussing the endosymbiotic theory of how mitochondria and chloroplasts originated from engulfed bacteria within early eukaryotic cells. The document utilizes diagrams and micrographs to illustrate key cellular structures.
This document provides an overview of the cell membrane. It begins with learning outcomes which state that students will be able to demonstrate cell organelles and describe the cell membrane. The contents then outline topics on the introduction, models, structure, composition and functions of the cell membrane. Key points made include that the cell membrane is a semipermeable barrier made of proteins, lipids and carbohydrates that separates the intracellular and extracellular fluids and regulates what passes in and out of the cell. The fluid mosaic model of the cell membrane is also described.
Tiếng Anh chuyên ngành Sinh học [03 lecture presentation]Tài liệu sinh học
- Water is essential for life on Earth and makes up 70-95% of living organisms. Its unique properties like polarity and hydrogen bonding allow water to moderate temperature, act as a solvent, and more.
- The pH scale measures how acidic or basic a solution is based on hydrogen ion concentration. Most biological fluids aim to be near neutral at pH 6-8.
- Acids and bases can change the pH of an environment, affecting chemical reactions in cells. Buffers help maintain pH within a tolerable range for organisms.
This chapter discusses how gene expression is controlled at the transcriptional level. It covers the basic mechanisms that regulate when and how often genes are transcribed from DNA into messenger RNA by RNA polymerase. Key players involved in transcriptional control include transcription factors, promoters, enhancers, silencers and chromatin structure.
Cell membranes are composed of lipids (45%), proteins (45%), and carbohydrates (10%). Lipids form a bilayer with hydrophilic heads facing out and hydrophobic tails facing inward. Membrane proteins can be peripheral or integral. Peripheral proteins attach to lipid heads while integral proteins span or embed within the membrane. Together, lipids and proteins give cell membranes a fluid mosaic structure and allow them to perform important functions like selectively regulating transport into and out of the cell.
The document summarizes centrosomes and centrioles. It discusses that centrosomes are located near the nucleus and are responsible for cell division, cytokinesis, and cytoskeleton formation. Within centrosomes are centrioles, which are made up of nine groups of microtubules arranged in a ring. Centrioles play important roles in cell division through organizing the mitotic spindle, cellular organization by organizing microtubules, and formation of cilia and flagella. Centriole duplication is coupled with the cell cycle and centrosome duplication occurs in early S phase through assembly of a new procentriole next to each parental centriole.
1) The document discusses a lecture on carbon and the molecular diversity of life from Campbell Biology.
2) Carbon is able to form four bonds with other atoms, allowing it to create large, complex molecules like proteins, DNA, carbohydrates, and other molecules essential for life.
3) Key functional groups on organic molecules include hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, phosphate, and methyl groups, which influence the properties and reactions of biological compounds.
This document is a PowerPoint presentation on the functional anatomy of prokaryotic and eukaryotic cells. It compares and contrasts the structures of prokaryotic and eukaryotic cells, focusing on key differences like prokaryotes lacking a nucleus and organelles. The presentation also examines the structures of bacterial cells in more detail, including cell shape, flagella, pili, the cell wall, and plasma membrane. It describes the different types of cell walls found in bacteria and their functions.
KEY CONCEPTS
5.1 Macromolecules are polymers, built from monomers
5.2 Carbohydrates serve as fuel and building material
5.3 Lipids are a diverse group of hydrophobic molecules
5.4 Proteins include a diversity of structures, resulting in a wide range of functions
5.5 Nucleic acids store, transmit, and help express hereditary
information
5.6 Genomics and proteomics have transformed biological inquiry and applications
Chapter 16: Molecular Basis of InheritanceAngel Vega
KEY CONCEPTS
16.1 DNA is the genetic material
16.2 Many proteins work together in
DNA replication and repair
16.3 A chromosome consists of a DNA molecule packed together with proteins
KEY CONCEPTS
10.1 Photosynthesis converts light energy to the chemical energy of food
10.2 The light reactions convert solar energy to the chemical energy of ATP and NADPH
10.3 The Calvin cycle uses the chemical energy of ATP and NADPH to reduce CO2 to sugar
10.4 Alternative mechanisms of carbon fixation have evolved in hot, arid climates
KEY CONCEPTS
12.1 Most cell division results in genetically identical daughter cells
12.2 The mitotic phase alternates with interphase in the cell cycle
12.3 The eukaryotic cell cycle is regulated by a molecular
control system
KEY CONCEPTS
18.1 Bacteria often respond to environmental change by
regulating transcription
18.2 Eukaryotic gene expression is regulated at many stages
18.3 Noncoding RNAs play multiple roles in controlling gene
expression
18.4 A program of differential gene expression leads to the different cell types in a multicellular organism
18.5 Cancer results from genetic changes that affect cell cycle control
KEY CONCEPTS
48.1 Neuron structure and organization reflect function in information transfer
48.2 Ion pumps and ion channels establish the resting potential of a neuron
48.3 Action potentials are the signals conducted by axons
48.4 Neurons communicate with other cells at synapses
KEY CONCEPTS
45.1 Hormones and other signaling molecules bind to target
receptors, triggering specific response pathways
45.2 Feedback regulation and coordination with the nervous system are common in endocrine signaling
45.3 Endocrine glands respond to diverse stimuli in regulating homeostasis, development,
and behavior
Bio chapter 2: A Chemical Connection to BiologyAngel Vega
KEY CONCEPTS
2.1 Matter consists of chemical elements in pure form and
in combinations called compounds
2.2 An element’s properties depend on the structure of its atoms
2.3 The formation and function of molecules depend on chemical bonding between atoms
2.4 Chemical reactions make and break chemical bonds
The document summarizes the immune system, including innate and acquired immunity. Innate immunity provides nonspecific defenses like physical barriers and phagocytes. Acquired immunity involves lymphocytes that specifically recognize pathogens. B cells produce antibodies, while T cells help activate other immune cells or kill infected cells. The immune system protects the body through barriers, cellular defenses, inflammation, and adaptive immune responses against infection in body fluids and cells.
KEY CONCEPTS
11.1 External signals are converted to responses within the cell
11.2 Reception: A signaling molecule binds to a receptor protein, causing it to change shape
11.3 Transduction: Cascades of molecular interactions relay
signals from receptors to target molecules in the cell
11.4 Response: Cell signaling leads to regulation of transcription or cytoplasmic activities
11.5 Apoptosis integrates multiple cell-signaling pathways
KEY CONCEPTS
13.1 Offspring acquire genes from parents by inheriting
chromosomes
13.2 Fertilization and meiosis alternate in sexual life cycles
13.3 Meiosis reduces the number of chromosome sets from diploid to haploid
13.4 Genetic variation produced in sexual life cycles contributes to evolution
Chapter 15: Chromosomal Basis of InheritanceAngel Vega
KEY CONCEPTS
15.1 Morgan showed that Mendelian inheritance has its physical
basis in the behavior of chromosomes: Scientific inquiry
15.2 Sex-linked genes exhibit unique patterns of inheritance
15.3 Linked genes tend to be inherited together because they are located near each other on the same chromosome
15.4 Alterations of chromosome number or structure cause
some genetic disorders
15.5 Some inheritance patterns are exceptions to standard
Mendelian inheritance
KEY CONCEPTS
14.1 Mendel used the scientific approach to identify two laws of inheritance
14.2 Probability laws govern Mendelian inheritance
14.3 Inheritance patterns are often more complex than predicted by simple Mendelian genetics
14.4 Many human traits follow Mendelian patterns of
inheritance
Chapter 50: Sensory and Motor MechansimsAngel Vega
KEY CONCEPTS
50.1 Sensory receptors transduce stimulus energy and transmit signals to the central nervous system
50.2 The mechanoreceptors responsible for hearing and
equilibrium detect moving fluid or settling particles
50.3 The diverse visual receptors of animals depend on light-
absorbing pigments
50.4 The senses of taste and smell rely on similar sets of sensory receptors
50.5 The physical interaction of protein filaments is required for muscle function
50.6 Skeletal systems transform muscle contraction into
locomotion
KEY CONCEPTS
4.1 Organic chemistry is the study of carbon compounds
4.2 Carbon atoms can form diverse molecules by bonding to four other atoms
4.3 A few chemical groups are key to molecular function
KEY CONCEPTS
9.1 Catabolic pathways yield energy by oxidizing organic
fuels
9.2 Glycolysis harvests chemical energy by oxidizing glucose to pyruvate
9.3 After pyruvate is oxidized, the citric acid cycle completes the energy-yielding oxidation of organic molecules
9.4 During oxidative phosphorylation, chemiosmosis couples electron transport to ATP synthesis
9.5 Fermentation and anaerobic respiration enable cells to
produce ATP without the use of oxygen
9.6 Glycolysis and the citric acid cycle connect to many other metabolic pathways
1. The eukaryotic cell contains membrane-bound organelles that compartmentalize functions. The endomembrane system, including the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, and vacuoles, regulates protein traffic and performs metabolic functions through the action of vesicles.
2. The nucleus houses most of the cell's DNA and controls its genetic functions. Ribosomes located on the rough endoplasmic reticulum or in the cytosol use information from DNA to synthesize proteins.
3. The endoplasmic reticulum modifies proteins and membranes. The Golgi apparatus further modifies and packages proteins and lipids for transport. Lysosomes digest macromolecules and recycle cellular
The document provides an overview of cell structure and function at multiple levels of organization. It discusses that cells are the basic unit of structure and function in living things. It then describes several organelles and structures within plant and animal cells and their specific functions, including the nucleus, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, mitochondria, chloroplasts, cytoskeleton, and cell wall in plant cells. Advanced microscopy techniques are also summarized that allow visualization of cellular structures at different magnifications.
The document provides an overview of a lecture on cell structure and function from Campbell Biology, 9th Edition. It discusses the key components and characteristics of prokaryotic and eukaryotic cells. The lecture covers cellular organelles such as the nucleus, endoplasmic reticulum, Golgi apparatus, lysosomes, mitochondria, and chloroplasts. It also summarizes the endosymbiotic theory of the evolutionary origins of mitochondria and chloroplasts.
This document provides an overview of cell structure and function. It describes the key components of prokaryotic and eukaryotic cells as viewed under light microscopes, including cellular compartments such as the nucleus, mitochondria, chloroplasts, endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, cytoskeleton, and cell wall. The functions of these cellular structures are explained, such as protein synthesis in the ribosomes, energy production in mitochondria, and photosynthesis in chloroplasts. Comparisons are made between prokaryotic and eukaryotic cells and between plant and animal cells.
Here is a mind map of the major structures found in a typical eukaryotic cell:
Cell Membranes
- Plasma Membrane
- Nuclear Envelope
Organelles
- Nucleus
- Nucleolus
- Chromatin
- Endoplasmic Reticulum
- Rough ER
- Smooth ER
- Golgi Apparatus
- Lysosomes
- Mitochondria
- Chloroplasts (in plant cells)
- Vacuoles (in plant and fungal cells)
- Cytoskeleton
- Microtubules
- Microfilaments
- Intermediate Filaments
Other Structures
- Ribosomes
- Centros
The document discusses cell structure and compares typical animal and plant cells. It explains different microscopy techniques used to study cells, such as light and electron microscopy. Key cellular structures are described for both animal and plant cells, including the cell membrane, nucleus, mitochondria, chloroplasts, endoplasmic reticulum, Golgi bodies, and more. The sizes and functions of organelles are also summarized. Prokaryotic cells like bacteria are introduced and compared to eukaryotic cells. Viruses are also briefly described.
1. The document summarizes key aspects of cell structure and function, including the history of cell discovery, the cell theory, components of eukaryotic and prokaryotic cells, and structures such as organelles, cytoskeleton, flagella, and nuclei.
2. Key organelles discussed include the nucleus, which contains DNA and controls the cell, mitochondria and chloroplasts, which generate energy for the cell, and the endoplasmic reticulum, Golgi apparatus, lysosomes, and vacuoles, which are involved in transport and storage.
3. Prokaryotic cells are described as generally smaller than eukaryotic cells and lacking membrane-bound organelles and nuclei.
1. The document discusses cells, which are the fundamental units of life. Cells come in different sizes, shapes, and structures depending on their function.
2. Cells can be either unicellular, consisting of a single cell, like euglena and paramecium, or multicellular, composed of multiple cells organized into tissues and organs, as seen in plants, animals, and fungi.
3. All cells contain a nucleus that houses the genetic material and controls cell functions, cytoplasm that contains organelles like mitochondria and the endoplasmic reticulum, and a plasma membrane that encloses the cell and regulates what enters and exits. The structures and components of cells allow them to carry out life-
The document discusses cells, their structure and function. It explains that cells are the basic unit of life and consist of a nucleus, cytoplasm, organelles, and a plasma membrane. The key components and functions of plant and animal cells are described. Specialized cell types are adapted to their specific functions through differences in shape, structures, and components. Cells combine to form tissues, organs and organ systems that work together to carry out essential life functions.
The document provides an overview of cell structure and function at different levels of magnification. It discusses how microscopes are used to visualize cells and cellular structures. Key organelles like the nucleus, endoplasmic reticulum, mitochondria, Golgi apparatus, lysosomes, and ribosomes are examined. The roles of the plasma membrane, endomembrane system, and genetic material housed in the nucleus are also summarized. Cell fractionation techniques are described which separate cell components based on size and density to isolate organelles for further study.
The document discusses the structure and function of cells. It defines a cell as the smallest unit capable of performing life functions. It outlines cell theory, which states that all living things are made of cells, cells are the basic units of life, and new cells are produced from existing cells. The document describes the main parts of the cell including the cell membrane, nucleus, cytoplasm, mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, and ribosomes. It explains the structure and functions of these organelles in supporting life processes within the cell.
This document provides an overview of cell organelles and their functions. It describes the endoplasmic reticulum, including rough ER which synthesizes proteins, and smooth ER which synthesizes lipids and regulates calcium. It also details the Golgi apparatus, mitochondria, lysosomes, peroxisomes, ribosomes, cytoskeleton, and nucleus. The key functions of each organelle are summarized such as protein synthesis, energy production, waste disposal, structural support, and genetic material storage.
2, origin, structure and function of eucaryotes cells 5 11-2012ganganaik
This document provides information about eukaryotic cell origin, structure, and function. It discusses how eukaryotic cells originated from prokaryotic cells through endosymbiotic theory. Eukaryotic cells have membrane-bound organelles like the nucleus, mitochondria and chloroplasts that allow for more complex structures and functions compared to prokaryotic cells. The document describes the key components of plant and animal cells including their cell membranes, cytoplasm, organelles, and differences between the two cell types.
The document provides an overview of cell structure and function. It discusses the key components of prokaryotic and eukaryotic cells including the plasma membrane, DNA, cytoplasm, organelles like the nucleus, endomembrane system, mitochondria and lysosomes. It also covers cell size limitations, the cytoskeleton, and structures specific to plant cells such as chloroplasts, central vacuoles and cell walls.
The document provides an overview of cell structure and function. It discusses the key components of prokaryotic and eukaryotic cells including the plasma membrane, DNA, cytoplasm, organelles like the nucleus, endomembrane system, mitochondria and lysosomes. It also covers cell size limitations, the cytoskeleton, and structures specific to plant cells such as chloroplasts, central vacuoles and cell walls.
IB Biology 1.2 Slides: Ultrastructure of CellsJacob Cedarbaum
Electron microscopes have much higher resolution than light microscopes due to the shorter wavelengths of electron beams. Prokaryotes like E. coli have a simple cell structure without compartments, containing a cell wall, plasma membrane, ribosomes, nucleoid, cytoplasm and other structures. They divide via binary fission. Eukaryotes have a compartmentalized cell structure containing organelles like the nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, and vacuoles. Organelles in specialized cells like pancreatic and leaf cells are adapted for their functions like enzyme secretion and photosynthesis.
There are two major types of cells - prokaryotic and eukaryotic. Prokaryotic cells are simpler cells found in bacteria and archaea that do not have internal organelles or a nucleus. Eukaryotic cells are more complex, with internal membranes and organelles like the nucleus, mitochondria and chloroplasts. All living things are made of these basic cellular units that have evolved different structures and functions.
The document discusses the structure and function of cells. It covers several key points:
1) Cells are the fundamental unit of life, and there are two main types - prokaryotic cells which lack membrane-bound organelles, and eukaryotic cells which do have organelles like the nucleus.
2) Both cell types contain ribosomes for protein synthesis, but eukaryotic cells also contain other membrane-bound structures like the endoplasmic reticulum, Golgi apparatus, mitochondria, vacuoles, and lysosomes which carry out specialized functions.
3) The plasma membrane regulates what enters and exits the cell, and the cytoskeleton provides structure and allows movement within the cell
This document discusses cells and their characteristics. It defines the cell as the basic unit of life and introduces the cell theory. The document compares and contrasts plant and animal cells, noting their similarities like the nucleus, cytoplasm, and cell membrane, as well as differences such as plant cells containing chloroplasts and a cell wall. Examples of specific cell types are provided, like muscle, blood, and xylem cells, along with diagrams showing their structures and functions.
Travis Hills' Endeavors in Minnesota: Fostering Environmental and Economic Pr...Travis Hills MN
Travis Hills of Minnesota developed a method to convert waste into high-value dry fertilizer, significantly enriching soil quality. By providing farmers with a valuable resource derived from waste, Travis Hills helps enhance farm profitability while promoting environmental stewardship. Travis Hills' sustainable practices lead to cost savings and increased revenue for farmers by improving resource efficiency and reducing waste.
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
Immersive Learning That Works: Research Grounding and Paths ForwardLeonel Morgado
We will metaverse into the essence of immersive learning, into its three dimensions and conceptual models. This approach encompasses elements from teaching methodologies to social involvement, through organizational concerns and technologies. Challenging the perception of learning as knowledge transfer, we introduce a 'Uses, Practices & Strategies' model operationalized by the 'Immersive Learning Brain' and ‘Immersion Cube’ frameworks. This approach offers a comprehensive guide through the intricacies of immersive educational experiences and spotlighting research frontiers, along the immersion dimensions of system, narrative, and agency. Our discourse extends to stakeholders beyond the academic sphere, addressing the interests of technologists, instructional designers, and policymakers. We span various contexts, from formal education to organizational transformation to the new horizon of an AI-pervasive society. This keynote aims to unite the iLRN community in a collaborative journey towards a future where immersive learning research and practice coalesce, paving the way for innovative educational research and practice landscapes.
Or: Beyond linear.
Abstract: Equivariant neural networks are neural networks that incorporate symmetries. The nonlinear activation functions in these networks result in interesting nonlinear equivariant maps between simple representations, and motivate the key player of this talk: piecewise linear representation theory.
Disclaimer: No one is perfect, so please mind that there might be mistakes and typos.
dtubbenhauer@gmail.com
Corrected slides: dtubbenhauer.com/talks.html
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
Authoring a personal GPT for your research and practice: How we created the Q...Leonel Morgado
Thematic analysis in qualitative research is a time-consuming and systematic task, typically done using teams. Team members must ground their activities on common understandings of the major concepts underlying the thematic analysis, and define criteria for its development. However, conceptual misunderstandings, equivocations, and lack of adherence to criteria are challenges to the quality and speed of this process. Given the distributed and uncertain nature of this process, we wondered if the tasks in thematic analysis could be supported by readily available artificial intelligence chatbots. Our early efforts point to potential benefits: not just saving time in the coding process but better adherence to criteria and grounding, by increasing triangulation between humans and artificial intelligence. This tutorial will provide a description and demonstration of the process we followed, as two academic researchers, to develop a custom ChatGPT to assist with qualitative coding in the thematic data analysis process of immersive learning accounts in a survey of the academic literature: QUAL-E Immersive Learning Thematic Analysis Helper. In the hands-on time, participants will try out QUAL-E and develop their ideas for their own qualitative coding ChatGPT. Participants that have the paid ChatGPT Plus subscription can create a draft of their assistants. The organizers will provide course materials and slide deck that participants will be able to utilize to continue development of their custom GPT. The paid subscription to ChatGPT Plus is not required to participate in this workshop, just for trying out personal GPTs during it.
2. •All organisms are made of cells
•The cell is the simplest collection of matter
that can live
•Cell structure is correlated to cellular function
•All cells are related by their descent from
earlier cells
3. Microscopy
• Scientists use microscopes to visualize cells
too small to see with the naked eye
• In a light microscope (LM), visible light
passes through a specimen and then
through glass lenses, which magnify the
image by refracting (bending) the light
• The minimum resolution of an LM is about
200 nanometers (nm), the size of a small
bacterium
4. Figure
6.2
10 m
1 m
0.1 m
1 cm
1 mm
100 µm
10 µm
1 µm
100 nm
10 nm
1 nm
0.1 nm Atoms
Small molecules
Lipids
Proteins
Ribosomes
Viruses
Smallest bacteria
Mitochondrion
Most bacteria
Nucleus
Most plant and
animal cells
Human egg
Frog egg
Chicken egg
Length of some
nerve and
muscle cells
Human height
Unaidedeye
LM
EM
Super-
resolution
microscopy
•LMs can magnify
effectively to about
1,000 times the size
of the actual
specimen
6. 1 µm
1 µm
Scanning electron
microscopy (SEM) Cilia
Longitudinal
section of
cilium
Transmission electron
microscopy (TEM)
Cross section
of cilium
• Two basic types of
electron microscopes
(EMs) are used to study
subcellular structures
• Scanning electron
microscopes (SEMs)
focus a beam of
electrons onto the
surface of a specimen,
providing images that
look 3D
• Transmission electron
microscopes (TEMs)
focus a beam of
electrons through a
specimen
• TEMs are used mainly to
study the internal
ultrastructure of cells
8. Isolating Organelles by Cell
Fractionation
• Cell fractionation takes cells apart and separates the major
organelles from one another
• Ultracentrifuges fractionate cells into their component
parts
Homogenization
Homogenate
Tissue
cells
Differential centrifugation
9. LE 6-5b
Pellet rich in
nuclei and
cellular debris
Pellet rich in
mitochondria
(and chloro-
plasts if cells
are from a plant)
Pellet rich in
“microsomes”
(pieces of plasma
membranes and
cells’ internal
membranes)
Pellet rich in
ribosomes
150,000 g
3 hr
80,000 g
60 min
20,000 g
20 min
1000 g
(1000 times the
force of gravity)
10 min
Supernatant poured
into next tube
10. Comparing Prokaryotic and
Eukaryotic Cells
• Basic features of all cells:
– Plasma membrane
– Semifluid substance called the cytosol
– Chromosomes (carry genes)
– Ribosomes (make proteins)
13. • Eukaryotic cells have DNA in a nucleus that is
bounded by a membranous nuclear envelope
• Eukaryotic cells have membrane-bound organelles
Name 2 in micrograph above.
• Eukaryotic cells are generally much larger than
prokaryotic cells
Type of microscope? Why?
Animal, plant, bacteria, or fungi? Why?
14. LE 6-7
Total surface area
(height x width x
number of sides x
number of boxes)
6
125 125
150 750
1
1
1
5
1.2 66
Total volume
(height x width x length
X number of boxes)
Surface-to-volume
ratio
(surface area ÷ volume)
Surface area increases while
Total volume remains constant
The logistics of carrying
out cellular metabolism
sets limits on the size of
cells
15. Hydrophilic
region
Hydrophobic
region
Carbohydrate side chain
Structure of the plasma membrane
Hydrophilic
region
Phospholipid Proteins
Outside of cell
Inside of cell 0.1 µm
TEM of a plasma membrane
•The plasma membrane is a selective barrier that allows sufficient
passage of oxygen, nutrients,
and waste to service the volume of the cell
•The general structure of a biological membrane is a double layer of
phospholipids
19. The Nucleus: Genetic Library of
the Cell
• The nucleus contains most of the cell’s
genes and is usually the most conspicuous
organelle
• The nuclear envelope encloses the nucleus,
separating it from the cytoplasm
20. LE 6-10
Close-up of nuclear
envelope
Nucleus
Nucleolus
Chromatin
Nuclear envelope:
Inner membrane
Outer membrane
Nuclear pore
Pore
complex
Ribosome
Pore complexes (TEM) Nuclear lamina (TEM)
1 µm
Rough ER
Nucleus
1 µm
0.25 µm
Surface of nuclear envelope
21. Ribosomes: Protein Factories in
the Cell
• Ribosomes are particles made of ribosomal
RNA and protein
• Ribosomes carry out protein synthesis in
two locations:
– In the cytosol (free ribosomes)
– On the outside of the endoplasmic reticulum
(ER) or the nuclear envelope (bound
ribosomes)
22. LE 6-11
Ribosomes
0.5 µm
ER Cytosol
Endoplasmic
reticulum (ER)
Free ribosomes
Bound ribosomes
Large
subunit
Small
subunit
Diagram of
a ribosome
TEM showing ER
and ribosomes
23. Concept 6.4: The endomembrane
system regulates protein traffic and
performs metabolic functions in the cell
• Components of the endomembrane system:
– Nuclear envelope
– Endoplasmic reticulum
– Golgi apparatus
– Lysosomes
– Vacuoles
– Plasma membrane
• These components are either continuous or
connected via transfer by vesicles
Inner life of a cell
24. The Endoplasmic Reticulum:
Biosynthetic Factory
• The endoplasmic reticulum (ER) accounts
for more than half of the total membrane in
many eukaryotic cells
• The ER membrane is continuous with the
nuclear envelope
• There are two distinct regions of ER:
– Smooth ER, which lacks ribosomes
– Rough ER, with ribosomes studding its surface
25. LE 6-12
Ribosomes
Smooth ER
Rough ER
ER lumen
Cisternae
Transport vesicle
Smooth ER Rough ER
Transitional ER
200 nm
Nuclear
envelope
26. • The smooth ER
– Synthesizes lipids
– Metabolizes carbohydrates
– Stores calcium
– Detoxifies poison (organ with
cells loaded with smooth ER?)
• The rough ER
– Has bound ribosomes
– Produces proteins and
membranes, which are
distributed by transport
vesicles
– Is a membrane factory for the
cell
28. LE 6-13
trans face
(“shipping” side of
Golgi apparatus) TEM of Golgi apparatus
0.1 µm
Golgi
apparatus
cis face
(“receiving” side of
Golgi apparatus)
Vesicles coalesce to
form new cis Golgi cisternaeVesicles also
transport certain
proteins back to ER
Vesicles move
from ER to Golgi
Vesicles transport specific
proteins backward to newer
Golgi cisternae
Cisternal
maturation:
Golgi cisternae
move in a cis-
to-trans
direction
Vesicles form and
leave Golgi, carrying
specific proteins to
other locations or to
the plasma mem-
brane for secretion
Cisternae
29. Lysosomes: Digestive
Compartments
• A lysosome is a membranous sac of
hydrolytic enzymes
• Lysosomal enzymes can hydrolyze proteins,
fats, polysaccharides, and nucleic acids
• Lysosomes also use enzymes to recycle
organelles and macromolecules, a process
called autophagy
31. Vacuoles: Diverse Maintenance
Compartments
• Vesicles and vacuoles (larger versions of
vacuoles) are membrane-bound sacs with varied
functions
• A plant cell or fungal cell may have one or
several vacuoles
• Food vacuoles are formed by phagocytosis
• Contractile vacuoles, found in many freshwater
protists, pump excess water out of cells
• Central vacuoles, found in many mature plant
cells, hold organic compounds and water
32. LE 6-15
5 µm
Central vacuole
Cytosol
Tonoplast
Central
vacuole
Nucleus
Cell wall
Chloroplast
Video: Paramecium VacuoleVideo: Paramecium Vacuole
33. Concept 6.5: Mitochondria and
chloroplasts change energy from one
form to another
• Mitochondria are the sites of cellular respiration
• Chloroplasts, found only in plants and algae, are
the sites of photosynthesis
• Mitochondria and chloroplasts are not part of the
endomembrane system
• Peroxisomes are oxidative organelles
34. The Evolutionary Origins of
Mitochondria and Chloroplasts
• Mitochondria and chloroplasts have
similarities with bacteria
– Enveloped by a double membrane
– Contain free ribosomes and circular double
stranded DNA molecules
– Grow and reproduce somewhat independently
in cells
• These similarities led to the
endosymbiont theory
35. • The endosymbiont theory suggests that
an early ancestor of eukaryotes engulfed
an oxygen-using nonphotosynthetic
prokaryotic cell
• The engulfed cell formed a relationship
with the host cell, becoming an
endosymbiont
• The endosymbionts evolved into
mitochondria
• At least one of these cells may have then
taken up a photosynthetic prokaryote,
which evolved into a chloroplast
36. Figure 6.16
Endoplasmic
reticulum
Nucleus
Nuclear
envelope
Ancestor of
eukaryotic cells (host cell)
Engulfing of oxygen-
using nonphotosynthetic
prokaryote, which
becomes a mitochondrion
Nonphotosynthetic
eukaryote
Engulfing of
photosynthetic
prokaryote
Mitochondrion
Mitochondrion
Chloroplast
Photosynthetic eukaryote
At least
one cell
37. Mitochondria: Chemical Energy
Conversion
• Mitochondria are in nearly all eukaryotic cells
• They have a smooth outer membrane and an
inner membrane folded into cristae
• The inner membrane creates two compartments:
intermembrane space and mitochondrial matrix
• Some metabolic steps of cellular respiration are
catalyzed in the mitochondrial matrix
• Cristae present a large surface area for enzymes
that synthesize ATP
39. Chloroplasts: Capture of Light
Energy
• The chloroplast is a member of a family of
organelles called plastids
• Chloroplasts contain the green pigment
chlorophyll, as well as enzymes and other
molecules that function in photosynthesis
• Chloroplasts are found in leaves and other green
organs of plants and in algae
• Chloroplast structure includes:
– Thylakoids, membranous sacs
– Stroma, the internal fluid
40. Figure 6.18
Chloroplast
Ribosomes Stroma
Inner
and outer
membranes
Granum
DNA
Thylakoid Intermembrane space
Diagram and TEM of chloroplast(a) (b) Chloroplasts in an
algal cell
(b)
1 μm
50 μm
Chloroplasts
(red)
41. Peroxisomes: Oxidation
• Peroxisomes are specialized metabolic
compartments bounded by a single membrane
• Peroxisomes produce hydrogen peroxide and
convert it to water
Chloroplast
Peroxisome
Mitochondrion
42. • The cytoskeleton is a network of fibers
extending throughout the cytoplasm
• It organizes the cell’s structures and
activities, anchoring many organelles
• It is composed of three types of molecular
structures:
– Microtubules (red)
– Microfilaments (green)
– Intermediate filaments (yellow)
44. Roles of the Cytoskeleton: Support,
Motility, and Regulation
• The cytoskeleton helps to support the cell
and maintain its shape
• It interacts with motor proteins to produce
motility
• Inside the cell, vesicles can travel along
“monorails” provided by the cytoskeleton
• Recent evidence suggests that the
cytoskeleton may help regulate biochemical
activities
45. Figure
6.21
0.25 μmVesiclesMicrotubule
SEM of a squid giant axon(b)
(a) Motor proteins “walk” vesicles along cytoskeletal
fibers.
(a)
Motor protein
(ATP powered)
Microtubule
of cytoskeleton
Receptor for
motor protein
Vesicle
ATP
46.
47.
48.
49. Microtubules
• Microtubules are hollow rods about 25 nm in
diameter and about 200 nm to 25 microns
long
• Functions of microtubules:
– Shaping the cell
– Guiding movement of organelles
– Separating chromosomes during cell division
Cross-section MT
51. Centrosomes and Centrioles
• In many cells, microtubules grow out from a
centrosome near the nucleus
• The centrosome is a “microtubule-
organizing center”
• In animal cells, the centrosome has a pair of
centrioles, each with nine triplets of
microtubules arranged in a ring
54. Cilia and Flagella
• Microtubules control the
beating of cilia and flagella,
locomotor appendages of
some cells
• Cilia and flagella differ in
their beating patterns
Video: ChlamydomonasVideo: Chlamydomonas
Video: Paramecium CiliaVideo: Paramecium Cilia
Cilia in inner ear
56. LE 6-23b
15 µm
Direction of organism’s movement
Motion of cilia
Direction of
active stroke
Direction of
recovery stroke
57. • Cilia and flagella share a common
ultrastructure:
– A core of microtubules sheathed by the plasma
membrane
– A basal body that anchors the cilium or
flagellum
– A motor protein called dynein, which drives the
bending movements of a cilium or flagellum
58. Figure 6.240.1 μm
0.5 μm
0.1 μm
Microtubules
Plasma
membrane
Basal
body
Longitudinal section
of motile cilium
(a)
Triplet
Cross section of
motile cilium
(b)
Outer microtubule
doublet
Motor proteins
(dyneins)
Central
microtubule
Radial spoke
Cross-linking
proteins between
outer doublets
Plasma
membrane
Cross section of basal body(c)
59. • How dynein “walking” moves flagella and
cilia:
– Dynein arms alternately grab, move, and
release the outer microtubules
– Protein cross-links limit sliding
– Forces exerted by dynein arms cause doublets
to curve, bending the cilium or flagellum
62. Microfilaments (Actin Filaments)
• Microfilaments are solid rods about 7 nm in
diameter, built as a twisted double chain of actin
subunits
• The structural role of microfilaments is to bear
tension, resisting pulling forces within the cell
• They form a 3D network just inside the plasma
membrane to help support the cell’s shape
• Bundles of microfilaments make up the core of
microvilli of intestinal cells
64. • Microfilaments that function in cellular
motility contain the protein myosin in
addition to actin
• In muscle cells, thousands of actin filaments
are arranged parallel to one another
• Thicker filaments composed of myosin
interdigitate with the thinner actin fibers
65. Figure 6.26
Muscle cell
0.5 µm
Actin
filament
Myosin
filament
Myosin
head Chloroplast
(a)
(b)
(c)Myosin motors in muscle cell contraction Cytoplasmic streaming in
plant cells
Amoeboid movement
Extending
pseudopodium
Cortex (outer cytoplasm):
gel with actin network
Inner cytoplasm
(more fluid)
100 µm
30 µm
66. • Localized contraction brought about by
actin and myosin also drives amoeboid
movement
• Pseudopodia (cellular extensions) extend
and contract through the reversible
assembly and contraction of actin subunits
into microfilaments
67. LE 6-27b
Cortex (outer cytoplasm):
gel with actin network
Amoeboid movement
Inner cytoplasm: sol
with actin subunits
Extending
pseudopodium
68. • Cytoplasmic streaming is a circular flow of
cytoplasm within cells
• This streaming speeds distribution of
materials within the cell
• In plant cells, actin-myosin interactions and
sol-gel transformations drive cytoplasmic
streaming
Video: Cytoplasmic StreamingVideo: Cytoplasmic Streaming
70. Intermediate Filaments
• Intermediate filaments range in diameter
from 8–12 nanometers, larger than
microfilaments but smaller than
microtubules
• They support cell shape and fix organelles
in place
• Intermediate filaments are more permanent
cytoskeleton fixtures than the other two
classes
71. Concept 6.7: Extracellular components
and connections between cells help
coordinate cellular activities
• Most cells synthesize and secrete materials
that are external to the plasma membrane
• These extracellular structures include:
– Cell walls of plants
– The extracellular matrix (ECM) of animal cells
– Intercellular junctions
72. Cell Walls of Plants
• The cell wall is an extracellular structure
that distinguishes plant cells from animal
cells
• The cell wall protects the plant cell,
maintains its shape, and prevents excessive
uptake of water
• Plant cell walls are made of cellulose fibers
embedded in other polysaccharides and
protein
73. Cell Walls of Plants
• Plant cell walls may have multiple layers:
– Primary cell wall: relatively thin and flexible
– Middle lamella: thin layer between primary walls
of adjacent cells
– Secondary cell wall (in some cells): added
between the plasma membrane and the primary
cell wall
• Plasmodesmata are channels between
adjacent plant cells
75. The Extracellular Matrix (ECM) of
Animal Cells
• Animal cells lack cell walls but are covered
by an elaborate extracellular matrix (ECM)
• The ECM is made up of glycoproteins such
as collagen, proteoglycans, and fibronectin
and other macromolecules. ECM proteins
bind to receptor proteins in the plasma
membrane called integrins.
• Functions of the ECM:
– Support
– Adhesion
– Movement
– Regulation
80. 6.33 Role of the extracellular matrix in cell differentiation
Basal lamina in
B induces
differentiation
81. Intercellular Junctions
• Neighboring cells in tissues, organs, or
organ systems often adhere, interact, and
communicate through direct physical
contact
• Intercellular junctions facilitate this contact
82. Plants: Plasmodesmata
• Plasmodesmata are channels that perforate plant cell walls
• Through plasmodesmata, water and small solutes (and
sometimes proteins and RNA) can pass from cell to cell
Cross-section
84. Animals: Tight Junctions,
Desmosomes, and Gap Junctions
• At tight junctions, membranes of neighboring cells
are pressed together, preventing leakage of
extracellular fluid
• Desmosomes (anchoring junctions) fasten cells
together into strong sheets
• Gap junctions (communicating junctions) provide
cytoplasmic channels between adjacent cells
85. LE 6-31
Tight junctions prevent
fluid from moving
across a layer of cells
Tight junction
0.5 µm
1 µm
0.1 µm
Gap junction
Extracellular
matrix
Space
between
cells
Plasma membranes
of adjacent cells
Intermediate
filaments
Tight junction
Desmosome
Gap
junctions
88. Connexin proteins create gap junctions
6 connexins/channel
A compartment of several cells
In center
89. The Cell: A Living Unit Greater Than
the Sum of Its Parts
• Cells rely on the integration of structures
and organelles in order to function
• Inner Life of A Cell
90. Nuclear Pore Complex is much more
complicated than just a simple
protein like the connexin protein of
gap junctions—Groups of scientists
are uncovering just how many
proteins interact to make up this
complex.
http://lab.rockefeller.edu/rout/resproj1
Editor's Notes
Figure 6.2 The size range of cells
Figure 6.3 Exploring microscopy
Concept Check 6.1
1. How do stains used for light microscopy compare with those used for electron microscopy?
➢Stains used for light microscopy are colored molecules that bind to cell components, affecting the light passing through, while stains used for electron microscopy involve heavy metals that affect the beams of electrons passing through
2. Which type of microscope would you use to study (a) the changes in shape of a living white blood cell and (b) the details of surface texture of a hair?
➢ a) light microscope (no damage to cell) b) scanning electron microscope (to study the detailed architecture of cell surfaces)
Both the SEM and TEM use electromagnets as lenses to bend the paths of the electrons, ultimately focusing the image onto a monitor for viewing.
Freeze fracture: making the specimen cold and then breaking it. Pic C has a flat surface of the membrane.
We’ve had separation via chromatography, polarity before. Now we can do it via centrifugation. It is actually common.
Application Cell fractionation is used to isolate (fractionate) cell components based on size and density.
Technique Cells are homogenized in a blender to break them up. The resulting mixture (homogenate) is centrifuged. The supernatant (liquid) is poured into another tube and centrifuged at a higher speed for a longer period. This process is repeated several times. This “differential centrifugation” results in a series of pellets, each containing different cell components.
➢The faster the centrifuge spins the smaller the pellets will be
Cell fractionation enables researchers to prepare specific cell components in bulk and identify their functions, a task not usually possible with intact cells.
Write an essay about these four common features in ALL cells
Figure 6.5 A prokaryotic cell
Bacteria have a cell wall (peptidoglycan is only present in cell walls)
Classification based on the type of cell wall (done via gram stain)
Thick Peptidoglycan Layer-- Cell Wall are long strains of sugar. Gram Positive absorb the stain and turn purple
N-acetylglucosamine (NAG)
N-acetylnuramic acid (NAM)
Thin Peptidoglycan Cell Wall – gram negative cell wall is composed of a thin layer plus an outer layer (more complex structure than Gram positive)
Right outside the plasma membrane is a cell wall.
Plasma membrane controls what goes in and out of the cell
Cell wall provides structure and keeps protection via osmotic pressure
Capsule (not on all bacteria) is a thick coating outside of the cell wall and secrete capsules to
Not involved in immune response
2 types-- simple polysaccharides which don’t elicit an immediate response
Ribosomes: different in eukaryotic (ads) than bacteria (7ds)
Prokaryotic Fimbriae: made of the protein pilin. Used to attach to other things—function.
Chromosomes: “blueprint to life”coding for all of the biological models than need to be made and passes it down from cell to cell
Flagella: have little embedded motors causing them to twirl. Function is for movement Clockwise twirl = forward counter
Sex Pilis: to pass a small portion of the genome. bacterial conjugation made by male bacteria composed of pillin
Transmission Electron Microscope because it’s a slice and you can see the cell
Animal Cell
Nuclear Envelope: protein and phospholipids. Function is to house the genetic material
Eukaryotic cells have compartmentalization that allow them to have bigger cells
Compartments = organelles
A high surface-to-volume ratio facilitates the exchange of materials between a cell and its environment.
Figure 6.8a Exploring eukaryotic cells (part 1: animal cell cutaway)
Concept Check 6.2
1 Briefly describe the structure and function of the nucleus, the mitochondrion, the chloroplast, and the endoplasmic reticulum.
➢Nucleus: Nuclear envelope: is a double membrane enclosing the nucleus; perforated by pores; continuous with ER.
Nucleolus: structure involved in production of ribosomes; a nucleus has one or more nucleoli.
Chromatin: material consisting of DNA and proteins; visible as individual chromosomes in a dividing cell
Mitochondrion: organelle where cellular respiration occurs and most ATP is generated; double-bound membrane; folded inner membrane; has some individual DNA
Chloroplast: photosynthetic organelle; converts energy of sunlight to chemical energy stored in sugar molecules; double bound membrane; inner thylakoids; individual DNA
ER: network of membranous sacs and tubes; active in membrane synthesis and other synthetic ad metabolic processes; has rough (ribosomal studded) and smooth regions
2. Imagine an elongated cell (such as a nerve cell) that measures 125 * 1 * 1 arbitrary units. Predict how its surface-to-volume ratio would compare with thosein Figure 6.7.Then calculate the ratio and check your prediction.
➢This cell would have the same volume as the cells in columns 2 and 3 but proportionally more surface area than in column 2 and less than in column 3. Thus, the surface-to-volume ratio should be greater than 1.2 but less than 6. To obtain the surface area, you'd have to add he area of the six sides 125 +125 +125 +125+1+1 = 502. The surface-to-volume ratio equals 502 divided by a volume of 125, or 4.0
The nucleus houses most of the cell’s DNA and Ribosomes. (Some genes are located in mitochondria and chloroplasts.)
➢use information from the DNA to make proteins
➢DNA is organized into discrete units called chromosomes
Mitochondria, Chloroplast, and Nucleus have a double membrane.
➢chromatin: The complex of DNA and proteins making up chromosomes
➢nucleolus: nuclear subdomain that assembles ribosomal subunits.
proteins imported from the cytoplasm are assembled with rRNA into large
and small subunits of ribosomes.
The nucleus directs protein synthesis by synthesizing messenger RNA (mRNA) according to instructions provided by the DNA. Once an mRNA molecule reaches the cytoplasm, ribosomes translate the mRNA’s genetic message into the primary structure of a specific polypeptide.
➢ribosomes are not membrane bounded and thus are not considered organelles.
➢cells active in protein synthesis also have prominent nucleoli
Endomembrane System Carries out many tasks:
➢synthesis of proteins
➢transport of proteins into membranes and organelles or out of the cell
➢metabolism and movement of lipids
➢detoxification of poisons
Vesicles: sacs made of membrane
Smooth ER: outer surface lacks ribosomes
➢Functions include: synthesis of lipids, metabolism of carbohydrates, detoxification of drugs and poisons, and storage of calcium ions.
➢
Rough ER: studded with ribosomes on the outer surface of the membrane, thus appearing “rough” through an electron microscope
➢membrane factory for the cell–it grows in place by adding membrane proteins and phospholipids to its own mem- brane.
➢glycoproteins: proteins with carbohydrates covalently bonded to them… most secretory proteins
Cis: Receiving; located near the ER
Trans: Shipping; gives rise to vesicles that pinch off and travel to other sites.
Products of the endoplasmic reticulum are usually modified during their transit from the cis region to the trans region of the Golgi apparatus.
Figure 6.13 Lysosomes
Chloroplast transfer solar energy from the sun to chemical energy.
Mitochondria is where cellular respiration occurs.
Endosymbiotic Theory
Figure 6.16 The endosymbiont theory of the origins of mitochondria and chloroplasts in eukaryotic cells
Figure 6.17 The mitochondrion, site of cellular respiration
Figure 6.18 The chloroplast, site of photosynthesis
Thylakoid Stack = Granum
Stromo: bat
Intermediate filaments are composed of a variety of proteins
Microtubules are made of tubulin
TEM because the resolution is too good for it to be SEM
Figure 6.21 Motor proteins and the cytoskeleton
Microtubule
Large, alpha and beta tubulin, cilia, flagella, and the spindle body are composed of microtubules
Responsible for cell and organelle movements
Microfilaments
Eukaryotic Cilia and Flagella have the 9+2
A lysosome is a vesicle that has a specific job
The basal body has nine triplets, anchors the organelle in the plasma membrane
The flagella and cilia have microtubules columns in the middle
Figure 6.24 Structure of a flagellum or motile cilium
Intermediate filaments are thicker than microfilaments