The document summarizes key aspects of cell structure and function. It describes that cells have three main parts - the plasma membrane, cytoplasm, and nucleus. The plasma membrane encloses the cell and regulates exchanges. The cytoplasm contains organelles that carry out metabolic processes. The nucleus houses genetic material and controls cellular activities. Cellular transport mechanisms like diffusion, osmosis, and active transport allow movement of molecules into and out of cells.
Cells are the basic, fundamental unit of life. So, if we were to break apart an organism to the cellular level, the smallest independent component that we would find would be the cell.
Cells are the basic, fundamental unit of life. So, if we were to break apart an organism to the cellular level, the smallest independent component that we would find would be the cell.
Biology Class 11 Chapter 8
FOR FURTHER DETAILS YOU CAN WATCH THE RELATED VIDEO AT THE GIVEN LINK
https://www.youtube.com/channel/UCxo06Nj-QWo_7SNvMyDnJCQ?view_as=subscriber
Cell: The cell is the ultimate structural and functional unit of the body.
The three principal constituents of the cell are:
1. Cell membrane
2. Cytoplasm and its organelles
3. Nucleus
Cell Structures and Functions In pathology.pptxVictory120660
Cell structure and function are fundamental to understanding biology. Here's a broad overview:
1. **Cell Structure:**
- **Cell Membrane:** Acts as a barrier, controlling the passage of substances in and out of the cell.
- **Cytoplasm:** Gel-like substance within the cell where organelles are suspended.
- **Nucleus:** Contains genetic material (DNA) and controls cell activities.
- **Organelles:** Structures within the cell with specific functions, such as mitochondria (energy production), endoplasmic reticulum (protein synthesis), Golgi apparatus (protein packaging), and lysosomes (digestion).
2. **Cell Function:**
- **Metabolism:** Cells carry out metabolic processes to maintain life, including energy production, nutrient breakdown, and waste removal.
- **Reproduction:** Cells can reproduce through processes like mitosis (cell division) or meiosis (reproductive cell division).
- **Homeostasis:** Cells maintain a stable internal environment by regulating processes like temperature, pH, and nutrient levels.
- **Communication:** Cells communicate with each other through chemical signals, allowing coordination within tissues and organ systems.
- **Differentiation:** Cells specialize into different types with specific functions during development, forming tissues and organs.
- **Response to Stimuli:** Cells can respond to external stimuli, such as light or chemicals, through processes like movement or changes in gene expression.
Understanding cell structure and function is crucial for comprehending biological processes at all levels, from the functioning of individual organisms to the interactions within ecosystems.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Biology Class 11 Chapter 8
FOR FURTHER DETAILS YOU CAN WATCH THE RELATED VIDEO AT THE GIVEN LINK
https://www.youtube.com/channel/UCxo06Nj-QWo_7SNvMyDnJCQ?view_as=subscriber
Cell: The cell is the ultimate structural and functional unit of the body.
The three principal constituents of the cell are:
1. Cell membrane
2. Cytoplasm and its organelles
3. Nucleus
Cell Structures and Functions In pathology.pptxVictory120660
Cell structure and function are fundamental to understanding biology. Here's a broad overview:
1. **Cell Structure:**
- **Cell Membrane:** Acts as a barrier, controlling the passage of substances in and out of the cell.
- **Cytoplasm:** Gel-like substance within the cell where organelles are suspended.
- **Nucleus:** Contains genetic material (DNA) and controls cell activities.
- **Organelles:** Structures within the cell with specific functions, such as mitochondria (energy production), endoplasmic reticulum (protein synthesis), Golgi apparatus (protein packaging), and lysosomes (digestion).
2. **Cell Function:**
- **Metabolism:** Cells carry out metabolic processes to maintain life, including energy production, nutrient breakdown, and waste removal.
- **Reproduction:** Cells can reproduce through processes like mitosis (cell division) or meiosis (reproductive cell division).
- **Homeostasis:** Cells maintain a stable internal environment by regulating processes like temperature, pH, and nutrient levels.
- **Communication:** Cells communicate with each other through chemical signals, allowing coordination within tissues and organ systems.
- **Differentiation:** Cells specialize into different types with specific functions during development, forming tissues and organs.
- **Response to Stimuli:** Cells can respond to external stimuli, such as light or chemicals, through processes like movement or changes in gene expression.
Understanding cell structure and function is crucial for comprehending biological processes at all levels, from the functioning of individual organisms to the interactions within ecosystems.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
2. • Cells are the structural units of all living things.
All cells arise from existing cells by the process
of cell division, in which one cell divides into
two identical cells.
• The English scientist Robert Hooke first
observed plant cells with a crude microscope in
the late 1600s. Then, in the 1830s two German
scientists, Matthias Schleiden and Theodor
Schwann, proposed that all living things are
composed of cells.
4. PARTS OF A CELL
A human cell has three main parts:
• The plasma membrane: the outer
boundary of the cell.
• The cytoplasm: the intracellular fluid
packed with organelles, small structures
that perform specific cell functions.
• The nucleus: an organelle that controls
cellular activities. The nucleus lies near the
cell’s center.
5.
6. A. THE PLASMA MEMBRANE
• The plasma membrane defines the extent
of a cell, thereby separating two of the
body’s major fluid compartments the
intracellular fluid within cells and the
extracellular fluid (ECF) outside cells. The
plasma membrane encloses cell contents,
mediates exchanges with the extracellular
environment, and plays a role in cellular
communication.
7.
8. Structure
The Fluid Mosaic Model
• The fluid mosaic model of membrane
structure depicts the plasma membrane as
an exceedingly thin (7–10 nm) structure
composed of a double layer of lipid
molecules with protein molecules dispersed
in it.
• The proteins which float in the fluid lipid
bilayer, form a constantly changing mosaic
pattern.
9. The Glycocalyx
• Plasma membrane contains a carbohydrate
rich area at the cell surface called glycocalyx.
Cell junctions.
• An epithelial cell is shown joined to adjacent
cells by three common types of cell junctions.
10. 1. Tight Junctions: Impermeable junctions
prevent molecules from passing through the
intercellular space.
2. Desmosomes: Anchoring junctions bind
adjacent cells together like a molecular
“Velcro” and help form an internal tension
reducing network of fibers.
3. Gap junctions: Communicating junctions
allow ions and small molecules to pass for
intercellular communication
11.
12. B. THE CYTOPLASM
The cellular material between the plasma
membrane and the nucleus, is the site of most
cellular activities. It consists of three elements:
–The cytosol
–Organelles
–Inclusions.
13. 1. The cytosol: it is the viscous, semitransparent
fluid in which the other cytoplasmic elements
are suspended.
2. The organelles are the metabolic machinery
of the cell. Each type of organelle carries out a
specific function for the cell.
3. The inclusions are chemical substances that
may or may not be present, depending on cell
type.
15. Ribosomes
• Dense particles
consisting of two
subunits, each
composed of
ribosomal RNA and
protein. Free or
attached to rough
endoplasmic
reticulum.
• The sites of protein
synthesis.
16. Rough endoplasmic reticulum
• Membranous system
enclosing a cavity, the
cistern, and coiling
through the cytoplasm.
Externally studded with
ribosomes.
• Sugar groups are attached
to proteins within the
cisterns. Proteins are
bound in vesicles for
transport to the Golgi
apparatus and other sites.
• External face synthesizes
phospholipids.
17. Smooth endoplasmic reticulum
• Membranous system
of sacs and tubules;
free of ribosomes.
• Site of lipid and steroid
(cholesterol)
synthesis, lipid
metabolism, and drug
detoxification.
18. Golgi apparatus
• A stack of flattened
membranes and
associated vesicles
close to the nucleus.
• Packages, modifies,
and segregates
proteins for secretion
from the cell, inclusion
in lysosomes, and
incorporation into the
plasma membrane.
19. Peroxisomes
• Membranous sacs of
catalase and oxidase
enzymes.
• The enzymes detoxify
a number of toxic
substances. The most
important enzyme,
catalase, breaks down
hydrogen peroxide.
21. Microtubules
• Cylindrical structures made of tubulin
proteins.
• Support the cell and give it shape. Involved
in intracellular and cellular movements.
Form centrioles and cilia and flagella, if
present.
22. Microfilaments
• Fine filaments composed of the protein
actin. Involved in muscle contraction and
other types of intracellular movement, help
form the cell’s cytoskeleton.
23. Intermediate filaments
• Protein fibers; composition varies. The
stable cytoskeletal elements; resist
mechanical forces acting on the cell.
24. Centrioles
• Paired cylindrical
bodies, each composed
of nine triplets of
microtubules.
• Organize a microtubule
network during mitosis
(cell division) to form
the spindle and asters.
Form the bases of cilia
and flagella.
25. Inclusions
• Inclusions includes stored nutrients such
as lipid droplets and glycogen granules,
protein crystals, pigment granules. Storage
for nutrients, wastes, and cell products.
27. 1. Cilia
• Short cell-surface
projections; each cilium
composed of nine pairs
of microtubules
surrounding a central
pair.
• Coordinated movement
creates a unidirectional
current that propels
substances across cell
surfaces.
28. 2. Flagellum
• Like a cilium, but
longer; only example
in humans is the
sperm tail. Propels the
cell.
29. 3. Microvilli
• Tubular extensions of
the plasma membrane;
contain a bundle of
actin filaments.
Increase surface area
for absorption.
30. C. NUCLEUS
• The nucleus is a spherical or oval-shaped
structure that usually is the most prominent
feature of a cell. Surrounded by the nuclear
envelope; contains fluid nucleoplasm,
nucleoli, and chromatin.
• Control center of the cell; responsible for
transmitting genetic information and
providing the instructions for protein
synthesis.
31.
32. Structure of the Nucleus
1. The nuclear envelope
2. Nucleoplasm
3. Chromatin
4. The nucleolus
33. Nuclear Envelope
• The nuclear envelope is a double-layered
membrane perforated with pores, which
control the flow of material going in and
out of the nucleus.
• The outer layer is connected to the
endoplasmic reticulum, communicating
with the cytoplasm of the cell. The
exchange of the large molecules (protein
and RNA) between the nucleus and
cytoplasm happens here.
34. Nucleoplasm
• A jelly-like (made mostly of water) matrix
within the nucleus
• All the other materials “float” inside
• Helps the nucleus keep its shape and
serves as the median for the
transportation of important molecules
within the nucleus
35. Chromatin
• Chromatin appears as a fine, unevenly
stained network, but special techniques
reveal it as a system of bumpy threads
weaving through the nucleoplasm.
– Chromatin is composed of approximately
– 30% DNA, our genetic material
– 60% globular histone proteins which package
and regulate the DNA
– 10% RNA chains, newly formed or forming
36. Chromosomes
• Chromosomes contain DNA in a condensed form
attached to a histone protein.
• Chromatin is comprised of DNA. There are two
types based on function.
– Heterochromatin: highly condensed,
transcriptionally inactive mostly located
adjacent to the nuclear membrane
– Eurochromatin: delicate, less condensed
organization of chromatin, located in a
transcribing cell
37. Functions
• The nucleus is often compared to the
“command center,” as it controls all
functions of the cell.
• It is important in regulating the actions
of the cells.
• It plays an important part in creating
the cell’s proteins.
• It is involved in important processes
dealing with DNA and other genetic
molecules.
38. DNA
• DNA or deoxyribonucleic acid, contains
the information needed for the creation
of proteins (which include enzymes and
hormones) and is stored in the nucleus,
as already said, in the form of chromatin
or chromosomes.
• The nucleus is the site of DNA
duplication, which is needed for cell
division (mitosis) and organism
reproduction and growth.
39.
40. RNA
• RNA are made fromthe DNA template:
1. Messenger RNA (mRNA) directs the synthesis
of a protein.
2. Ribosomal RNA (rRNA) joins with ribosomal
proteins to make ribosomes.
3. Transfer RNA (tRNA) binds to an amino acid
and holds it in place on a ribosome until it is
incorporated into a protein during translation
41. Proteins and Cell Regulation
• The nucleus oversees cells’ functions and
regulatory mechanisms for keeping the cell
healthy and alive.
• The nucleus controls growth of the cell through
the synthesis of structural proteins, energy and
nutrient metabolism.
• The nucleus regulates the secretion of
ribosomes, which are made in the nucleolus
and are the sites of gene transcription.
42. Molecule Movement
• Passive Transport
• Active Transport
• Endocytosis
(phagocytosis & pinocytosis)
• Exocytosis
43. Passive Transport
• No energy required
• Move due to gradient
– differences in concentration, pressure, charge
• Move to equalize gradient
– High moves toward low
44. Types of Passive Transport
1. Diffusion
2. Osmosis
3. Facilitated diffusion
46. Osmosis
• Special form of diffusion
• Fluid flows from lower solute concentration
• Often involves movement of water
– Into cell
– Out of cell
47. Solution Differences
• Solvent + solute = solution
• Hypotonic
– Solutes in cell more than outside
– Outside solvent will flow into cell
• Isotonic
– Solutes equal inside & out of cell
• Hypertonic
– Solutes greater outside cell
– Fluid will flow out of cell
48.
49. Facilitated Diffusion
• Differentially permeable membrane
• Channels (are specific) help molecule or
ions enter or leave the cell
• Channels usually are transport proteins
(aquaporins facilitate the movement of
water)
• No energy is used
50. Process of Facilitated Transport
• Protein binds with molecule
• Shape of protein changes
• Molecule moves across membrane
52. Endocytosis
• Movement of large material
– Particles
– Organisms
– Large molecules
• Movement is into cells
• Types of endocytosis
– bulk-phase (nonspecific)
– receptor-mediated (specific)
53. Process of Endocytosis
• Plasma membrane surrounds material
• Edges of membrane meet
• Membranes fuse to form vesicle