The document discusses the structure and function of prokaryotic and eukaryotic cells. It describes that cells are the fundamental unit of life and are classified as prokaryotic or eukaryotic. Prokaryotic cells are smaller, lack organelles, and their DNA is not enclosed in a nucleus. Eukaryotic cells are larger, have membrane-bound organelles, and their DNA is contained within a nucleus. The document proceeds to describe key cellular components of eukaryotic cells including the nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, and cytoskeleton. It provides details on their morphology, functions, and role in cellular processes.
Nucleus: Structure and function
nuclear membrane
nuclear lamins
Nuclear pore complexe
nuclear matrix, composition and its role
cajal bodies
SFCs
nuclear speckles
PML bodies
Nucleolus
Nucleus: Structure and function
nuclear membrane
nuclear lamins
Nuclear pore complexe
nuclear matrix, composition and its role
cajal bodies
SFCs
nuclear speckles
PML bodies
Nucleolus
Presentation include Nucleus and its components like nuclear envelope, nucleolus, chromatin fibers, ultra structure of nucleus and its general functions.
Nucleus” is a Latin word meaning Kernel
It is the “CONTROL CENTER” of the cell
Average diameter of nucleus is 6um, which occupies around 10% of cell volume
Nuclear Envelope
Nuclear Pores and complex
Nuclear lamina
Chromosomes & Chromatin
Nucleolus
Nucleoplasm
Describe the nonmembranous organelles of a typical cell with their structure and specific functions.
Summarize the process of protein synthesis.
Presaented by-
Dr. Subarna Das
Resident, Dept. of Anatomy, BSMMU
Guided by-
Dr. Zinnat Ara Yasmin
Asst. Prof, Dept. of Anatomy, BSMMU
Presentation include Nucleus and its components like nuclear envelope, nucleolus, chromatin fibers, ultra structure of nucleus and its general functions.
Nucleus” is a Latin word meaning Kernel
It is the “CONTROL CENTER” of the cell
Average diameter of nucleus is 6um, which occupies around 10% of cell volume
Nuclear Envelope
Nuclear Pores and complex
Nuclear lamina
Chromosomes & Chromatin
Nucleolus
Nucleoplasm
Describe the nonmembranous organelles of a typical cell with their structure and specific functions.
Summarize the process of protein synthesis.
Presaented by-
Dr. Subarna Das
Resident, Dept. of Anatomy, BSMMU
Guided by-
Dr. Zinnat Ara Yasmin
Asst. Prof, Dept. of Anatomy, BSMMU
Discovered by an English biologist Robert Brown in 1831.
It is also know as the, “Brain of the cell” or “Control centre of the cell”
On the basis of absence and presence of nucleus cell may be divided into Prokaryotes and Eukaryotes respectively.
NUMBER- Mostly uninucleate
Binucleate – Hepatocytes,Chondryocytes, fungi
Polynucleate- Tapetal cell, myocytes
Anucleated Cell- Red Blood cell
Sieve tube element
Component of Nucleus Nuclear membrane
Nuclear pore
Nucleoplasm
Nucleolus
Chromatin
Nuclear Membrane :Also called the nuclear envelope, is a double membrane layer that separates the contents of the nucleus from the rest of the cell.
The nuclear membrane is a lipid bilayer, meaning that it consists of two layers of lipid molecules.
Outer Layer: The outer layer of lipids has ribosomes, structures that make proteins, on its surface. It is connected to the endoplasmic reticulum.
Inner Membrane: Network of fibers and proteins attached to the inner membrane is called the nuclear lamina. It structurally supports the nucleus, plays a role in repairing DNA, and regulates events in the cell cycle such as cell division and the replication of DNA.
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
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
2. Introduction
• All organism are build from
cells.
• All animal including human
are also organized from
collections of cells thus, cell is
the fundamental unit of life
3. TYPES OF CELLS
• In general two types of cells
exists in nature
They are,
– The prokaryotic cell
–The eukaryotic cells
4. PROKARYOTIC CELL
• This name is derived from the
Greek, pro-before and karyon-
nucleus. cells are smaller in size.
• Eg. Bacteria , cyanobacteria .
5. EUKARYOTIC CELLS
• The eukaryotic cells (Greek ;
Eu – true and Karyon –
nucleus) include the protists ,
fungi , plants and animals
including humans . cells are
larger in size.
6. PROKARYOTIC CELL
• Smaller in size 1 to
10 micro meter.
• Mainly unicellular.
• Single cell
membrane
surrounded by
rigid cell wall.
EUKARYOTIC CELLS
• Larger in size 10 to
100 or more.
• Multicellular.
• Lipid bilayer
membrane with
proteins.
7. • Anaerobic or
aerobic.
• Not well defined
nucleus, only a
nuclear zone
with DNA.
• Aerobic.
• Well defined
nucleus 4-6
micrometer in
diameter contains
DNA and
surrounded by a
perinuclear
membrane.
8. • Histone absent
• No nuclei.
• Cytoplasm contains
no cell organelles.
• Ribosome’s present
free in cytoplasm
• Presence of Histone.
• Nucleolus present
rich in RNA.
• Membrane bound
cell organelles are
present
• Ribosome’s
studded on outer
surface of ER
9. • Mitochondria
absent. Enzymes
of energy
metabolism bound
to membrane
• Golgi apparatus
absent. Storage
granules with
polysaccharides.
• Mitochondria
present power
house of the cell.
• Golgi apparatus
present flattened
yingle membrane
vesicles
10. • Lysosomes –
absent
• Cell division
usually by
fission, no
mitosis.
• Lysosomes
Present -single
membrane vesicle
containing packets
of hydrolytic
enzymes
• Cell division by
mitosis
11. • Cytoskeleton –
absent
• RNA and protein
synthesis in
same
compartment
• Eg.bac cyanobac,
rickettsii
• Cytoskeleton –
present
• RNA synthesized
and processed in
nucleus .proteins
synthesized in
cytoplasm.
• Eg. protists, fungi,
plants and animals
14. NUCLEUS
• spherical or ellipsoidal in
shape
• double layered nuclear
envelope
• outer layer is continuous with
the endoplasmic reticulum
15. • inner layer gives attachment to
the chromosomes
• Contain nuclear pore
• 3000 – 4000 in number
• allow particles less than 9nm to
pass
16.
17. NUCLEAR ENVELOPE
• segregated from the cytoplasm by a
double membrane
• The two membranes separates from
each other by peri nuclear space
• Width - 100 -300A
• Absent during the cell division
18. • The two membranes of the nuclear envelope
are roughly parallel
• separated by perinuclear space
• discountinuous except some areas where the
membranes join to form pore complex.
• frequently coated with ribosomes
• inner layer possesses a crystalline layer
• often coated with filaments and fibrous
structures
19. PORE COMPLEX
• The nuclear envelope is interrupted at
intervals by nuclear pores
• passage ways for transport
• contain some electron- dense materials
• enclosed by some annular material
• These circular structures are called annuli,
which is along with pore form a pore complex.
20. FUNCTION OF NUCLEAR ENVELOPE
• The nuclear envelope separate the cell interior
into two compartments –cytoplasm and
nucleoplasm.
• It act as a transporter to transport materials
between two compartments.
• Act as a diffusion barrier to small cation and
anion.
• Transport very large molecules like
nucleoproteins, macromolecules and other
materials from nucleoplasm to cytoplasm.
21. NUCLEAR MATRIX
• nuclear envelope is made up of a dense- jelly
like mass
• composed of two compartments
– Nuclear gel or karyolymph and chromatin.
– Nucleolus and chromatin
22. Nuclear gel
• Nuclear gel is highly granular, containing
fibrous material
• rich in proteins and small percentage of DNA,
RNA and phospholipids
• replication of DNA,
• transcription and
• transport of substance takes place
23. Chromatin
• chromatin in nucleolus is present in
condensed form called heterochromatin
• matrix also has a network of non –
chromatin material forming
interchromatinic matrix
24. NUCLEOLUS
• Nucleus contain one (or) more dense
bodies called nucleoli (or)
plasmosomes
• present in all eukaryotic nuclei
except sperm
25. STRUCTURE OF NUCLEOLUS
• dense, heavy staining interior surrounded by a
light staining external layer
• nucleus contains one large or two small
nucleoli
• chromosomes have specific sites or nucleolar
organizing region
• responsible for their synthesis and organize
them into dense bodies, engaged in protein
synthesis
26. Function of nucleolus
–Transcription of the genes that code
ribosomal RNA.
–Processing of peri ribosomal molecule
–Assembly of ribosomal subunits
27. CHROMATIN
• Basis of heredity
• Human chromatin fibre has a
diameter of about 20 nm
• contains DNA, RNA and protein
(Histone)
• DNA sequences are functionally
inactive
28. • RNA is less than 10 percent of the mass of
DNA
• The fibre is folded within the chromatid along
its length in a specific manner. It has been
hypothesized that there is a single DNA helix
in each chromatid. This is known as uniname
hypothesis
29. NUCLEOSOME
• each bead chromatin is a discrete unit called
nucleosome
• nucleosomes are connected by a fine thread,
the free DNA duplex
• Nucleosomes can be isolated by treating
chromatin with an endonuclease, micrococcal
nuclease, which cut DNA in between the
nucleosome
30. MITOCHONDRIA
• Present in all eukaryotic aerobic cells
• Supply biological energy, and they do so
primarily by oxidizing the substrates of the
Kreb cycle
• cell gets its energy from the enzymatic
oxidation of chemical compounds within the
mitochondria, hence they are generally
referred to as “power house” of the cell.
31. LOCATION
• uniformly distributed in the cytoplasm
• accumulated in the peripheral cytoplasm
• structures where energy requirements are the
heaviest, (muscle cells, secretary cells etc)
• structures where energy requirements are the
heaviest, (muscle cells, secretary cells etc)
32. SHAPE AND SIZE
• different shapes ranging from granular to
filamentous depending upon the functional
state of the cell
• spherical in yeast, elliptical in kidney,
elongated in liver cell and filamentous in
fibroblast
• 0.5μ wide and 0.5 to 0.7μ long
33. STRUCTURE
• According to Palade
– smooth outer membrane
– inter membrenal space - 60 – 70 Å wide
– inner membrane - invagination called cristae
– matrix,
– the mitochondrial lumen
– 70Å thick
– cristae – villose, finger like
34.
35. • matrix is filled with a dense
proteinaceous materials
• the sites for binding divalent cations
• cristae is packed with lollipop like
particles, elementary particles - F1
particle
• elementary particle has a hexagonal basal
plate, a stalk and a knob like structure
• Contain four electron transfer complex I, II, III,
and IV
36. • outer membrane also bears elementary
particles but lack basal plate and stalk
• The outer membrane particle harbor NAD+
linked dehydrogenase
• the particle of the inner membrane are rich
enzymes of the respiratory chain and electron
transport system.
39. Outer membrane Intermediate
space
Inner membrane Matrix
FA elongation
system
Ubiquinone Isocitrate
dehydrogenase
Phospholipase A Electron
transferring flavo-
protein (ETF)
α-oxo-glutarate
dehydrogenase
Malate
dehydrogenase
40. Outer membrane Intermediate
space
Inner membrane Matrix
Nucleoside
diphosphokinase
Vector ATP
synthetase
FA oxidation system
β–OH-butyrate
dehydrogenase
Ornithine
transcarbamolylase
Carnitine-
palmityl
transferase
Carbamoyl
phosphate
synthetase- I
All translocases
41. FUNCTION
• Most of the metabolisms are carried out
mitochondria.
• Mitochondrion is specialized for the rapid
oxidation of NADH and FAD.
• The energy produced is trapped and stored as
ATP for future use of energy in the body
42. Clinical aspect
• lufts disease, involving mitochondrial energy
transduction
• Parkinsons disease - Age related degenerative
disorders
• cardio myopathy
43. ENDOMEMBRANE SYSTEM
• several interrelated membrane-bound
compartments - endomembrane system
• important role in cellular activities
• Includes
– chloroplast, mitochondria , golgi , micro bodies ,
vacuoles etc
44. ENDOPLAMIC RETICULUM
• several membrane complexes that are
interconnected by several separate organelles
• they are involved in protein synthesis,
transport, modification, storage and secretion.
45. MORPHOLOGY OF ER
• Three morphological patterns
– Granular (or) rough endoplasmic reticulum (RER)
– Smooth ER.
– Lamellar and vesicular ER
46. ROUGH ER
• forms a lace-like system
• In sections they appear as cisternae
• The cisternae are tubular, closed at the ends and
bear numerous ribosomes load with rich RNA
deposits.
• The ribosomal particles give them a rough
appearance
47. • Ribosomes are found on the outer surface of the
ER attached through mRNA
• giving rise to spiral or rosette shaped structure
• Proteins are found at the interface between the
ribosomes and the membranes of the ER.
• synthesized protein are then transferred to the
lumen of cisternae to the cytoplasm depending on
the nature and function of synthesized proteins.
48. SMOOTH ER
• The membrane lacks ribosome
• found in continuation with the RER
• engaged in lipid metabolism
• special significance in mycofibrils which
contract after receiving the stimulus
49. LAMELLAR AND VESICULAR ER
• ER reticulum exists in lamellar, tubular and
vesicular forms also
• lamellar form -more or less similar to RER
• Granular lamellae - derived from the outer
membrane of the nuclear envelope
• annulated lamellae - originate as small
vesicles - pinched off from the nuclear
membrane
50. CHEMISTRY OF ENDOPLASMIC
RETICULUM
• enzyme glucose-6-phosphate - almost present
in the membrane and it is used as a marker of
ER
• enzymes present in the ER are utilized for the
synthesis of triglycerides, phosphatides
glycolipids, plasmalogen, fatty acid,
cholesterol
53. FUNCTION
• Involved in secretion, synthesis, modification
and transport of compounds.
• Act like a circulatory system. The molecules,
metabolites and ions may circulate through
them.
• Responsible for the transport of nucleoprotein
and RNA from the nucleus to the cytosol.
• Detoxify hydrocarbons or carcinogen.
54. • In the cells engaged in protein synthesis
the rough ER always predominates,
where as cells involved in lipid synthesis
SER predominant.
• Involved in the biosynthesis of
cholesterol, synthesis of hormone and
bile acids.
57. GOLGI COMPLEX
• Discoverer, Comillo golgi
• important role in the secretory process
• secretions are mostly synthesized in the rough
endoplasmic reticulum
• passed through the golgi complex
• stored in the secretory or storage vesicles
clustered in the vicinity of the golgi complex
58. MORPHOLOGY
• shallow saucer-shaped bodies or narrow neck-
bowl like forms
• consisting of
–interconnecting tubules,
–vesicles and
–cisternae
59. 3 components
• Stacks of flatted disc or cisternae.
• Bunches of tubules and small vesicles
• Large vesicles filled with amorphous materials
60. • Large vesicles are appear at the periphery of
the cisternae
• small vesicles are found in clusters at the
cisternal tips or in the curvature of cisternae
as small elliptical, oval or circular bodies
61. • The cisternae are polarized structure having a
forming face, in close proximity to the nuclear
envelope.
• The curvature of the cisternae is known as the
maturing face in whose concavity a number of
secretory vesicles are lodged.
• It often contains small sac like structure rich in
alkaline phosphates
62. CHEMICAL COMPOSITION
• 60 percent proteins and 40 percent lipid
materials
• phospholipids are present in the form of
phosphatidyl choline
• The carbohydrates are in the form of glucose,
glucosamine, galactose, mannose and fucose
63. • Enzymes
–glycosyl transferase -transfers
oligosaccharides to protein components
–thiamine pyrophosphatase, acid
phosphatase and several hydrolase of the
lysosomal type are also present in the golgi
64. FUNCTION
• It is an important link in the secretary
pathway.
• intermediary between the endoplasmic
reticulum and the secretary granule.
• formation of plant cell wall
65. • Primary lysosomes originates from the
maturating face of the golgi complex.
• formation of lysosome like organelles in the
sperm (acrosome).
• Acrosome is rich in hyaluronidase which
lyses the protective covering of the ovum. So
as to allow the entry of the sperm.
66. LYSOSOME
• Bound by limiting membrane and rich in
hydrolase of acidic nature
• size ranges from 0.1 to 5.0 μm
• Four types
– PRIMARY LYSOSOME
– SECONDARY LYSOSOME
– AUTO LYSOSOME
– TELO LYSOSOME
67. • PRIMARY LYSOSOME: Newly formed - virgin
lysosome
• SECONDARY LYSOSOME - digestion of
exogenous materials or cells of own
intracellular substances – phagolysosome
• AUTO LYSOSOME: (Autophagic vacuoles) arise
by fusion of primary lysosome
• TELO LYSOSOME: Aged lysosome - when they
degenerate, the left over vesicles are known as
residual bodies or post lysosome
68. FUNCTION
• Participation in cellular digestion.
• Exogenous materials such as
macromolecules and colloidal substance
entering the cells through pinocytosis are
digested called heterophagy.
69. PINOCYTOSIS
• In this mechanism substances are incorporated
into the cell.
• These materials are absorbed on the plasma
membrane and the affected area invaginate to
form pinocytic vesicles containing the absorbed
materials.
• These vesicles are eventually pinched off into the
cytoplasm as membrane bound vesicles and
latter fuse to form phagosome.
•
70. • Phagosome fuse with lysosome resulting in
secondary lysosome or phagoglycosome.
• The lysosomal enzyme digest the material
useful to the cell diffuses into the cytoplasm,
leaving behind the unwanted portions in the
vesicles.
• These vesicles are known as residual bodies.
These are removed by reverse pinocytosis.
71. PEROXISOMES
• similar to lysosomes having a diameter of about
500nm
• formed from the smooth endoplasmic reticulum
• contain enzyme oxidases
• peroxisomes in a cell is increased by a variety of
chemicals like clofibrate (drug for
hyperlipidemia), some herbicides and industrial
plasticizers.
• This may lead to hepatic cancer in the long term
72. FUNCTION
• Combined with vacuoloplasm enzyme it
catalyse a variety of metabolic
reaction.(ex: catabolism of very long fatty
acid)
• Play a useful role in detoxifying
poisonous substance. Ex. Alcohol
73. INTRACELLULAR VESICLES
• also membrane bound and contain either
solids or liquids
• contents of the vesicles may be in the process
of being taken up by the cell (endocytic
vesicle), ejected from the cell (exocytic vesicle)
or being transferred from one organelle to
another (transport vesicles)
74. RIBOSOMES
• granules of about 15nm in diameter
• site of protein synthesis
• Individual ribosomes consist of ribosomal
RNA, and protein,
• Their sizes are generally expressed in S
value
75.
76.
77. Ribosome
• two types of ribosome which are
differentiated on the basis of their
sedimentation properties
–70S ribosome and
–80S ribosomes - eukaryotes
78. • two unequal subunits (large and small).
• appear in a string like arrangement when
attachment to the messenger RNA - called
polyribosomes or polysomes
80. CYTOSKELETON
• The cytoskeleton is a complex,dynamic
network of interlinking protein filaments
present in the cytoplasm of the cell. It extends
from the cell nucleus to the cell membrane
and is composed of similar proteins in the
various organisms.
81. FUNCTION
• The cytoskeleton gives a cell
– Its shape
– Offer support
– Facilitates movement through three main
components
–Microfilaments
–Intermediate filaments
–Microtubules
