This document discusses cell organelles. It describes the structures and functions of various membranous organelles like mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, and peroxisomes. It also discusses non-membranous organelles such as ribosomes, cytoskeleton components, centrioles, and cell inclusions. The key organelles and their roles in cellular processes are summarized, with comparisons made between related structures like rough and smooth endoplasmic reticulum. Micrographs are also included to show organelle features under light and electron microscopy.
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: 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
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.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
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Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
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.
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. Objectives
1. Discuss the ultra-structure of different cell organelles and correlate
with function.
2. Identify the microscopic characteristic of each organelle.
2
3. Cell organelles
❑ Membranous organelles ( bounded
by membranes ) such as
mitochondria, Golgi complex,
nucleus, endoplasmic reticulum,
lysosomes & peroxisomes.
❑ Non- membranous organelles (not
bounded by membranes) such as
ribosomes, centrioles &
cytoskeleton.
3
4. Mitochondria
• They are found where metabolic activity is high
such as those of liver and skeletal muscle, thus
termed the powerhouse of the cell.
• Found in all cells except mature red blood cells.
• Mitochondria are very mobile, moving around
the cell by means of microtubules, a component
of the cytoskeleton
4
5. • Under Light microscope(L/M ): Thread-like, rod-shaped organelles.
• Under Electron microscope (E/M):
1. They have an outer smooth and inner irregular folded membrane
(cristae).
2. The cristae, which project into the matrix and greatly increase the
membrane’s surface area
The number of cristae in mitochondria also corresponds to the energy needs
of the cell.
L/M E/M
5
6. ❑ The space found in between the two
membranes is called intermembranous space.
❑Inside the inner membrane is the Matrix Space.
❑The matrix space consists of:
I. Circular molecular of DNA and three varieties of
RNA.
II. Rounded electron dense granules rich in Ca+2.
III. Enzymes for the citric acid (Krebs)cycles.
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7. Endoplasmic reticulum
• A system of interconnected tubules and vesicles whose lumen is
termed cisternae
• It is either : rough or smooth.
• It may be covered by ribosomes ( rER )
• May have NO ribosomes (sER)
7
8. Rough endoplasmic reticulum
• Increase in cells having high protein
secretion (e.g. Fibroblast).
• Sometimes continuous with the outer
nuclear membrane.
• Functions:
1. Synthesis of proteins (via ribosomes)
2. Storage and transport of proteins.
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9. Smooth endoplasmic reticulum
• The SER is made up of tubules and vesicles that
branch out to form a network.
• NO attached ribosomes.
• Its cisternae are more tubular.
• Functions:
1. The principal functions of smooth endoplasmic
reticulum are lipid biosynthesis (e.g steroid
hormones) and membrane synthesis and repair.
2. Calcium ion storage
3. Drug detoxification
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11. Golgi apparatus
• The organelle was named after histologist
Camillo Golgi who discovered it in 1898.
• Composed of series of flattened, slightly
curved cisternae (Golgi stack).
• Has two surfaces:
• Cis-face: immature & close to RER
• Trans-face: mature & toward the cell
membrane
• The periphery of each cisterna is dilated
and show vesicles that are fusing with or
budding off.
11
13. Function of Golgi Apparatus
It modifies proteins that have been delivered in transport vesicles from the RER.
The Golgi apparatus modifies, sorts, and packages different substances for secretion
out of the cell, or for use within the cell.
13
14. Lysosomes
• Usually spherical membranous vesicles formed by the Golgi
apparatus .
• They contain more than 40 different degradative enzymes including
proteases, lipases and nucleases.
• These are collectively known as acid hydrolases because they are
optimally active at a pH of about 5.0
• Increase in cells with high phagocytic activity (e.g. macrophages).
14
15. Lysosomes
• Primary lysosomes : which are newly formed from Trans-face
of Golgi
• Secondary lysosomes: which are formed from the fusion of
primary lysosomes with other substances.
• Functions:
1. Digestion of certain substances such as solid material,
fluids and dead organelles.
2. Cell metabolism: Lysosomes are important in breakdown
of intracellular glycogen e.g. in liver cells.
3. Phagocytosis of bacteria and viruses so contribute in
defense mechanism
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17. Ribosomes
• Non-membranous cell organelles, about
20 nm in diameter.
• They are formed in nucleus and then pass
to the cytoplasm to perform their
functions.
• The main function are proteins synthesis.
• Each ribosome is composed of a large and
a small subunit
17
18. • Each subunit consists of a strand of
RNA (ribosomal RNA, rRNA) with
associated ribosomal proteins
forming a globular structure.
• Ribosomes are often found attached
to mRNA molecules in small spiral-
shaped aggregations called
polyribosomes or polysomes
• Ribosomes and polyribosomes may
be free or attached to the surface of
endoplasmic reticulum.
18
19. Cytoskeleton
• A network of protein filaments.
• Responsible for keeping the cell
morphology, help in cellular
motion. Consist of :
1.Microtubules.
2.Thin filaments(microfilaments).
3.Intermediate filaments.
19
20. 1) Microtubules
• Tubular structures consist of α and β tubulin.
• Their synthesis is controlled by the microtubule organizing centers.
• Keep the cell shape.
• Transport of organelles and vesicles, such as secretory granules.
20
21. 2) Intermediate filaments
• They are intermediate in size with an average diameter of 10-12 nm.
• Types of intermediate filaments :
A. Keratins are found in epithelium.
B. Desmin is found in smooth muscle skeletal and cardiac muscle.
C. Vimentin filaments are found in the cells of mesemchymal origin
(e.g. fibroblast).
D. Glial filaments in the astrocytes.
E. Neurofilaments consist of several polypeptides in the nerve cells.
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22. 3) Microfilaments
• Mainly contractile thin (actin) and
thick (myosin) filaments in the skeletal
muscle.
• They form a thin sheath under plasma
membrane called the cell cortex .
• Help in moving cytoplasmic
components.
• Help in cleavage of mitotic cells.
22
23. Centrioles
• They are non membranous organelles.
• By E.M.: Non membranous small paired structures
arranged at right angle to each other.
• One pair of centrioles is called a centrosome. Each
centriole is cylinder in shape.
• In cross section, the wall of the centriole is formed of
9 bundles of microtubules and each bundle is formed
of 3 microtubules (triplet), embedded in fibrillar
material.
• Function: They are essential for cell division to
form mitotic spindle.
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24. Cell Inclusions
• Non-living components of the cell.
• The most common inclusions are glycogen, lipid droplet and
pigments.
• Glycogen is very common, abundant in cells of muscle and liver.
Pigments: hemoglobin of red blood cells and melanin manufactured
by melanocytes.
• Lipids: stored mainly in specialized cells, adipocytes in the form of
triglycerides. They work for energy reserve
24
29. References
• Mescher, A. L., Mescher, A. L., & Junqueira, L. C. U. (2016).
Junqueira's basic histology: Text and atlas (14th ed.). New York:
McGraw-Hill Education.
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