This document provides an overview of cell structures and microscopy techniques used to study cells. It discusses the main components of plant and animal cells, including the cell membrane, nucleus, mitochondria, chloroplasts, vacuoles, cell wall, and cytoskeleton. It also describes different types of microscopes like light microscopes, electron microscopes, SEM, and TEM and how they are used to view cell structures at varying levels of magnification and resolution. Key similarities and differences between plant and animal cells are also highlighted.
Cell biology is the study of cell structure and function, and it revolves around the concept that the cell is the fundamental unit of life. Focusing on the cell permits a detailed understanding of the tissues and organisms that cells compose.
Cell biology is the study of cell structure and function, and it revolves around the concept that the cell is the fundamental unit of life. Focusing on the cell permits a detailed understanding of the tissues and organisms that cells compose.
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
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
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.
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.
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!
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.
A Strategic Approach: GenAI in EducationPeter 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.
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.
3. Cells
⚫ ALL organisms are made up of cells
⚫ Simplest collection of LIVING matter
⚫ Cell structure correlate to their functions
⚫ All cells are related to earlier cells that they descend
from
5. Microscopy
⚫ Microscope is an instrument that magnifies objects
too small to be seen, producing an image that
appears larger.
⚫ Photographs/ pictures of cells derived from the
microscope - Micrographs
6. Magnification
⚫ A measure how much larger a microscope can
cause an object to appear
⚫ The Ratio of the object to its actual size
(Magnification = measured length[of image]/ actual
length of object)
7.
8.
9. Resolution
⚫ A measure of clarity – the smallest distance by
which two points can be distinguished in an image.
⚫ Limited by the physical properties of light
10. Light Microscope
⚫ Commonly used
⚫ Visible light passes through
the specimen
⚫ Bent through the lens system
– producing magnified image
⚫ X1000 magnification
⚫ Uses blue light – 400 nm
⚫ Lowest Resolution = 200nm
13. Light Colors
⚫ Light with the largest wavelength is red = 700 nm
⚫ Light with smallest wavelength is blue = 400 nm
⚫ With the magnification, resolution is actually half the
wavelength
⚫ Light microscope uses blue – 200 nm resolution
14. Electron microscope
⚫ Uses electron – has a
shorter wavelength
⚫ X-ray is hard to control –
electron can be controlled
using magnets
⚫ Electron can only function
in vacuum – oxygen
molecules may cause the
electron to be knocked
around
⚫ False-coloring by computer
15. SEM
⚫ Scanning Electron
microscope
⚫ Electron bounce back
and forth across
specimen’s surface
⚫ Creating a detailed 3D
image
⚫ Resolution smaller that
TEM
17. Light Vs. Electron
Similarities
⚫ Both uses
Lens
Differences
⚫ One uses visible light, another uses electron molecule
(electron vs. photon)
⚫ Resolution, one is 200, the other is 0.5
⚫ With SEM – 3D image is possible
⚫ Electron is more expensive
⚫ One focuses light with lens, the other focuses light by
electromagnetic control
⚫ One uses electron gun, the other uses low voltage
bulb
⚫ On magnifies up to 1500, the other up to 500000
⚫ One uses air as medium, another uses vacumm
18. Cell Fractionation
⚫ Takes cell apart and separates organelles
⚫ Cells are centrifuged where the heavier components
will sink to the bottom
⚫ Ultracentrifuges – fractionates them into
components
23. Prokaryotic
⚫ Prokaryote – a simple organism e.g. Bacteria
⚫ No nucleus
⚫ No membrane-bound organelles
⚫ Has Cell Walls
⚫ Has Circular chromosomes
⚫ Common cell structures: Plasma membrane,
Cytoplasm, DNA, Ribosomes
27. Animal Cell Structure
⚫ Nucleus: Contains chromosomes/ DNA – code for the
synthesis of proteins that control the function of the cell –
hence the nucleus commands the cell
⚫ Cell Surface membrane: Holds the cell content, controls
the ins/outs, structural forms, cell recognition, adhesion,
signaling, transport of substances, endo/exocytosis
⚫ Cytoplasm: the liquid where all the cell metabolic
activities take place
⚫ Mitochondria: Produces energy in the form of ATP
through respiration
28. Animal Cell Structure
⚫ Ribosomes: Receiving mRNA coded for Protein
synthesis
⚫ Lysosome: Engulfs materials and destroy them with
enzymes
⚫ Rough ER: Has ribosomes on it – involved in protein
synthesis – transport network for protein
⚫ Smooth ER: Synthesis of lipid – involved in cell
detoxification
⚫ Golgi bodies: Process the finished proteins
29. Nucleus
⚫ Double nuclear envelope –
encloses/ protect DNA
⚫ Nuclear pore – received
substances for DNA
Replication(extra phosphate),
exits for mRNA
⚫ small molecules pass through
by diffusion, large ones get in
actively
⚫ in micrographs – RNA/protein
complex can be seen
plucking the pore
30. Nucleus
⚫ Nucleoplasm – contains
chromatin granules,
DNA/associated proteins:
during cell division, they
condense to form
chromosomes
⚫ Nucleolus – produces rRNA
part of ribosomes, proteins,
coenzymes, enzymes for
nucleic acid synthesis, RNA
⚫ Outer membrane continuous
with ER – easier transport
31. Endoplasmic Reticulum
⚫ A system of hollow tubes/ sacs – transportation
purpose
nucleus
Rough
Endoplasmic
Reticulum
Smooth
Endoplasmic
Reticulum
32. Rough ER
⚫ Covered with ribosomes
⚫ Interconnected system of
flattened sacs
⚫ Ribosomes on surface
synthesize proteins which are
then transported through the
interconnected system
⚫ RER is abundant in cells which
needed to produce a lot of
proteins for exports e.g.
Digestive enzymes/ growth
33. Smooth ER
⚫ Lacks ribosomes
⚫ A system of interconnected
tubules
⚫ Carbohydrate/ lipids metabolism
⚫ Synthesizes: triglycerides,
phospholipid, cholesterol
⚫ Modification of steroid hormones
⚫ High percentage in cells
involved with metabolism of
lipids/drugs
34. Golgi Body
⚫ Flattened cisternae
⚫ Invaginate/ fuse to form
vesicles
⚫ Internal transports by
vesicles
⚫ Vesicles protect molecules
⚫ In case of enzymes –
protect the cells
35. Cell Membrane
⚫ Fluid mosaic bilayers which surround the cell content
⚫ Control the ins/outs of the cell
⚫ Gives the cell stability during temperature changes
⚫ Endocytosis/ exocytosis
⚫ Important in cell recognition
⚫ Cell signaling
⚫ Cell adhesion
36. Cytoplasm
⚫ Makes up of liquid: Cytosol
⚫ Where the metabolism takes place
⚫ Contains water/ solution
⚫ Most organelles float here
⚫ Osmoregulation
37. Mitochondria
⚫ Double Membrane – isolate
certain reaction – high
concentration of enzymes/
substrates can be maintained
⚫ Outer membrane –
permeable to salt, sugar,
nucleotides
⚫ Inner membranes –
selectively permeable
(control chemical composition
of the matrix – optimizes
enzyme activity)
38. Mitochondria
⚫ Porins on inner membranes – entry of
oxygen/pyrovic acid – exit of ATP/ Carbon dioxide
⚫ Folded inner membrane (cristae) – increases
surface area for enzymes/ coenzymes
⚫ 70s ribosomes – protein manufacturing
⚫ Loop of circular DNA – codes for protein
⚫ Enzymes
39.
40. Endosymbiosis theory
⚫ States that mitochondria’s
ancestors were bacterial
ingested by a eukaryote
⚫ The eukaryote kept it as it is
useful for respiration
⚫ Evidences: 70s vs. 80s
ribosomes
⚫ Evidences: Own DNA
⚫ Evidences: Divides by itself
41. Ribosomes
⚫ 2 subunits
⚫ Made of rRNA/ Protein
⚫ rRNA – formed in nucleus –
moves out via pores
⚫ Protein part – assembled in
the cytoplasm
⚫ Found as dense clusters
(polysomes)
⚫ On membranes of RER
42. Lysosomes
⚫ Vesicles that contains
hydrolytic enzymes
⚫ Break down old organelles –
recycle the materials
⚫ Break down storage
molecules
⚫ Break down whole cell when
it dies
43. Cytoskeleton
⚫ Microtubules – tubulin proteins : Thickest fo the
three – around 25 nm
⚫ Microfilaments – actin proteins
⚫ Intermediate filaments
44. Microfilament
⚫ Rods of about 7nm in diameter
⚫ Made up of a twisted double chain of actin subunits
45. Microfilaments
⚫ Create tension
⚫ Support the shape of the cell
⚫ 3-D Cortex inside plasma membrane
⚫ Bundles of microfilaments indie the microvilli
48. Microtubules
⚫ 25 nm wide
⚫ Made up of tubulin proteins
⚫ Arranged in dimers (alpha tubulin/ beta tubulin)
⚫ This dimer repeat in vertical format – forming a
protofilament
⚫ 13 protofilaments arrange around a hollow core
⚫ MICROTUBULES FORM
49. Microtubules
⚫ Shapes the cell
⚫ Guide the movements of cells/ organelles – with
help of motor proteins
⚫ Make up spindles that separate chromosomes
during cell division
50. Centrosome
⚫ Contains 2 centrioles
⚫ The location for MTOC (Microtubules organizing
center)
⚫MAY have a role in regulating the cell division
51. Centrioles
⚫ Microtubules form triplets (1
complete microtubule, 2 partial
microtubules)
⚫ These triplets then arrange into a
cylinder
⚫ 200 nm in diameter, 500 nm long
⚫ Two of these line up perpendicular
to form centriole
⚫ Not sure of its function yet
⚫ Some believe it might be MTOCs
for spindles during cell division
52.
53. Cilia/ Flagella
⚫ Long structures projecting out of a cell membrane
⚫ A core of microtubules sheathed by the plasma
⚫ Flagellum – longer and for movement of cell
⚫ Cilia – shorter – usually to beat up things
56. Cell Wall
⚫ Cellulose fiber embedded in
other polysaccharides/
proteins
⚫ Pectin and cellulose fiber
(strong)
⚫ Permeable
⚫ Space between cells above
the wall: middle lamella
⚫ Things like wood may have
secondary cell wall
57. Cell Wall
⚫ The osmotic pressure vs. the pressure from cell wall
gives the plant its structure
⚫ Structure of Cellulose – resistant to degradation and
enzymes – only cellulase – Protects the cell
⚫ Prevent bursting
58. Cell Wall
⚫ May have multiple layers
1. Primary Cell Wall – thin and flexible
2. Middle lamella – a thin layer between primary walls
and adjacent cells
3. Secondary cell wall (only found in certain cells) :
between plasma membrane and primary cell wall –
on the inside where it grows
59.
60. Cell Wall
⚫ Tunnels between cells: Plasmodesmata
⚫ Protoplast:A plant, bacterial or fungal cell with its
cell wall removed
61. Vacuoles
⚫ Enclosed membrane
compartments – filled with water
content/ enzymes/ proteins etc.
⚫ Storage for waste, harmful
materials
⚫ Storage for water
⚫ Hydrostatic pressure controlled
⚫ Work with cell wall to maintain
turgidity
⚫ The membrane around it:
Tonoplast
62. Chloroplasts
⚫ Plant organelles specialized in conducting
photosynthesis
⚫ Larger than mitochondria
⚫ Double membrane
⚫ Has its own DNA
⚫ Endosymbiosis theory applied to it as well
63.
64. Chloroplast
⚫ Inner/ Outer membrane
⚫ Stroma: The liquid inside the inner membrane
⚫ Grana: Made up of stacks of thylakoid
⚫ Thylakoid: Has chlorophyll on the surface
65. Virus
⚫ Size: 20 – 750 nm
⚫ We are not sure if virus
is considered an
organism
⚫ As it is unable to fully
function without a host
⚫ Nevertheless, virus is a
fascinating component
to Biology worthy of
studies
66. Virus Structure
⚫ Consists of an RNA molecule
protected by a protective
protein coat called capsid
⚫ Capsid made up of proteins
called capsomere
⚫ On the outside a protein
envelope gives it another
layer of protection
⚫ Glycoproteins/lipids stuck out
from the envelope
67. Plant Cell Vs. Animal Cell
Common
⚫ Nucleus
⚫ ERs/ Golgi body
⚫ Plasma membranes
⚫ Phospholipid bilayer
⚫ Mitochondria
⚫ Gap between cells (gap junction/
Plasmodesmata)
⚫ Both have cytoskeleton
⚫ Peroxisomes
Differences
⚫ Cell Wall
⚫ Cell membrane: Glycolipid/
Glycoprotein
⚫ Centrioles
⚫ Central vacuoles
⚫ Chloroplasts