structure of human cell: human cell is the basic structural and functional unit of life which having a cytoplasmic region, nucleus and a plasma membrane . the word cell is coined by the scientist Robert Hook in the year of 1665 . cell organelles and their functions . function of the cell and each organelles functions
Cytoplasm. Within cells, the cytoplasm is made up of a jelly-like fluid (called the cytosol) and other structures that surround the nucleus. Scientists concluded that the average human body contains approximately 37.2 trillion cells
Animal cells are typical of the eukaryotic cell, enclosed by a plasma membrane and containing a membrane-bound nucleus and organelles. Unlike the eukaryotic cells of plants and fungi, animal cells do not have a cell wall. This feature was lost in the distant past by the single-celled organisms that gave rise to the kingdom Animalia. Most cells, both animal and plant, range in size between 1 and 100 micrometers and are thus visible only with the aid of a microscope.
All living organisms are made of cells and cellular products. The cell is the smallest structural, functional, and biological unit of all living organisms. It can capable of biosynthesis, replication and energy transformation. All cellular organelles carry out specific functions that are necessary for the normal functioning of the cell. Animal cells work together and function interdependently. Human cells vary in size, shape, and function. Most animal cells are so small they can only be seen with the aid of a microscope. Based on function, there are more than 200 different kinds of animal cells that help each system contribute to the homeostasis of the entire body. Despite their many differences, human cells have several similar structural features: a cell membrane, a nucleus, and cytoplasm and cell organelles.
structure of human cell: human cell is the basic structural and functional unit of life which having a cytoplasmic region, nucleus and a plasma membrane . the word cell is coined by the scientist Robert Hook in the year of 1665 . cell organelles and their functions . function of the cell and each organelles functions
Cytoplasm. Within cells, the cytoplasm is made up of a jelly-like fluid (called the cytosol) and other structures that surround the nucleus. Scientists concluded that the average human body contains approximately 37.2 trillion cells
Animal cells are typical of the eukaryotic cell, enclosed by a plasma membrane and containing a membrane-bound nucleus and organelles. Unlike the eukaryotic cells of plants and fungi, animal cells do not have a cell wall. This feature was lost in the distant past by the single-celled organisms that gave rise to the kingdom Animalia. Most cells, both animal and plant, range in size between 1 and 100 micrometers and are thus visible only with the aid of a microscope.
All living organisms are made of cells and cellular products. The cell is the smallest structural, functional, and biological unit of all living organisms. It can capable of biosynthesis, replication and energy transformation. All cellular organelles carry out specific functions that are necessary for the normal functioning of the cell. Animal cells work together and function interdependently. Human cells vary in size, shape, and function. Most animal cells are so small they can only be seen with the aid of a microscope. Based on function, there are more than 200 different kinds of animal cells that help each system contribute to the homeostasis of the entire body. Despite their many differences, human cells have several similar structural features: a cell membrane, a nucleus, and cytoplasm and cell organelles.
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 fundamental unit of life is cell. It is briefly explained about it in this ppt , actually you can read this for school exams too. Thank you please leave a like
Cell :Structure & Functions for Medical and Health allied StudentsRajendra Dev Bhatt
The cell is the basic structural and functional unit of all known living organisms.
It is the smallest unit of life that is classified as a living thing, and is often called the building block of life.
Cell Anatomy and physiology ( structure and function for NEET asparients, Biology, MBBS, BPT, Allied, nursing , medical and paramedical students. This is the easiest form of slide share to understand the context better.
eukaryote, any cell or organism that possesses a clearly defined nucleus. The eukaryotic cell has a nuclear membrane that surrounds the nucleus, in which the well-defined chromosomes (bodies containing the hereditary material) are located.
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 fundamental unit of life is cell. It is briefly explained about it in this ppt , actually you can read this for school exams too. Thank you please leave a like
Cell :Structure & Functions for Medical and Health allied StudentsRajendra Dev Bhatt
The cell is the basic structural and functional unit of all known living organisms.
It is the smallest unit of life that is classified as a living thing, and is often called the building block of life.
Cell Anatomy and physiology ( structure and function for NEET asparients, Biology, MBBS, BPT, Allied, nursing , medical and paramedical students. This is the easiest form of slide share to understand the context better.
eukaryote, any cell or organism that possesses a clearly defined nucleus. The eukaryotic cell has a nuclear membrane that surrounds the nucleus, in which the well-defined chromosomes (bodies containing the hereditary material) are located.
A microarray is a laboratory tool used to detect the expression of thousands of genes at the same time. DNA microarrays are microscope slides that are printed with thousands of tiny spots in defined positions, with each spot containing a known DNA sequence or gene.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
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.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
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.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
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.
Richard's aventures in two entangled wonderlandsRichard 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.
2. •The individual cells can grow, reproduce, process information,
respond to stimuli, and carry out an amazing array of chemical
reactions. These abilities define life.
•Cells come in an amazing variety of sizes and
shapes.
•All cells share certain structural features and carry out
many complicated processes in basically the same way.
3. A cell is chemical system that is able to maintain its structure and reproduce.
Cells are the fundamental unit of life. All living things are cells or composed of
cells
4. Cell Theory
•Cells are the fundamental unit of life -nothing less than
a cell is alive.
•All organisms are constructed of and by cells.
•All cells arise from preexisting cells. Cells contain the
information necessary for their own reproduction. No
new cells are originating spontaneously on earth today.
•Cells are the functional units of life. All biochemical
processes are carried out by cells.
•Groups of cells can be organized and function as
multicellular organisms
•Cells of multicellular organisms can become specialized
in form and function to carry out sub-processes of
multicellular organisms
5.
6. Macromolecules that make the cell
ATP : energy storage and signaling
Proteins: structural components, transporters, enzymes
Sugars: structural components, source of energy
Vitamins: co factors of enzymes or precursors
Ions: change electrical properties of a cell to generate action potential
Nucleic acids: carry genetic information
7. Cellular Organelles
Nucleus-the largest and most obvious membrane bound compartment -
controls cell activities contains
the nucleolus-a darkened region where ribosomal RNA is synthesized
contains chromosomes-consist of DNA wrapped around proteins
Nucleus is surrounded by the nuclear envelope-a double membrane Nuclear
membrane has nuclear pores that control entry and exit of materials
8. •Most of the cell’s ribosomal RNA is synthesized in the
nucleolus
•The finished or partly finished ribosomal subunits, as
well as tRNAs and mRNA-containing particles, pass through
a nuclear pore into the cytosol for use in protein synthesis
•replicating DNA and synthesizing rRNA, tRNA, and
mRNA.
10. Endosomes
• small membrane-bounded vesicle that contains extracellular
material and is delivered to an early endosome, a sorting station of
membrane-limited tubules and vesicles. The endocytic pathway
ends when a late endosome delivers its membrane and internal
contents to lysosomes for degradation
Lysosomes
• lysosomes are responsible for degrading certain components that have
become obsolete for the cell or organism. The process by which an aged
organelle is degraded in a lysosome is called autophagy (“eating
oneself”). Materials taken into a cell by endocytosis or phagocytosis also
may be degraded in lysosomes .
Nuclease, protease, phosphatases
11. • Cytosolic and nuclear proteins generally are not
degraded in lysosomes but rather in proteasomes,
large multiprotein complexes in the cytosol
• All the lysosomal enzymes work most efficiently at
acid pH values and collectively are termed acid
hydrolases. Two types of transport proteins in the
lysosomal membrane work together to pump H and Cl
ions (HCl) from the cytosol across the membrane,
thereby acidifying the lumen
12. Peroxisomes
Peroxisomes contain several oxidases—enzymes that use molecular
oxygen to oxidize organic substances, in the process forming hydrogen
peroxide (H2O2), a corrosive substance. Peroxisomes also contain
copious amounts of the enzyme catalase, which degrades hydrogen
peroxide to yield water and oxygen
peroxisomal oxidation of fatty acids yields acetyl groups and is not
linked to ATP formation. The energy released during peroxisomal
oxidation is converted into heat, and the acetyl groups are transported
into the cytosol, where they are used in the synthesis of cholesterol
and other metabolites.
Plant seeds contains, small organelles that oxidize stored lipids as a source
of carbon and energy for growth. They are similar to peroxisomes and
contain many of the same types of enzymes as well as additional ones
used to convert fatty acids into glucose precursors.
Glyoxisome
13. Endoplasmic reticulum (ER)—an extensive network of closed,
flattened membrane-bounded sacs called cisternae
Functions: synthesis of lipids, membrane proteins and secreted
proteins. The smooth endoplasmic reticulum is smooth because it lacks
ribosomes. In contrast, the cytosolic face of the rough endoplasmic
reticulum is studded with ribosomes.
The Smooth Endoplasmic Reticulum: The synthesis of fatty acids and
phospholipids takes place in the smooth ER. Enzymes in the smooth ER
of the liver also modify or detoxify hydrophobic chemicals such as
pesticides and carcinogens by chemically converting them into more
water-soluble, conjugated products that can be excreted from the body.
High doses of such compounds result in a large proliferation of the
smooth ER in liver cells.
The Rough Endoplasmic Reticulum : Ribosomes bound to the rough ER
synthesize certain membrane and organelle proteins and virtually all
proteins to be secreted from the cell.
14. The Golgi Complex
•Proteins synthesized in rough ER leave the ER in small transport
vesicles and reach Golgi Complex.
•The enzymes in the Golgi complex modify the different
kind of proteins depending on their structures and final destination.
•They are transported out of the complex by a second set of
vesicles, which seem to bud from the trans side of the Golgi
complex.
15. Vacuoles:
•Most plant cells contain at least one membrane limited internal
vacuole.
•A variety of transport proteins in the vacuolar membrane
allow plant cells to accumulate and store water, ions, and
nutrients
•the lumen of a vacuole contains a battery of degradative
enzymes and has an acidic pH, which is maintained by
similar transport proteins in the vacuolar membrane.
the vacuolar membrane is permeable to water but is poorly
permeable to the small molecules stored within it. Because
the solute concentration is much higher in the vacuole lumen
than in the cytosol or extracellular fluids, water tends to
move by osmotic flow into vacuoles- Cell Expansion
16. Mitochondria
•the main sites of ATP production during aerobic metabolism, are
generally exceeded in size only by the nucleus, vacuoles, and
chloroplasts.
•In eukaryotic cells, the initial stages of glucose degradation take
place in the cytosol, where 2 ATP molecules per glucose molecule are
generated. The terminal stages of oxidation and the coupled
synthesis of ATP are carried out by enzymes in the mitochondrial
matrix and inner membrane. As many as 28 ATP molecules per
glucose molecule are generated in mitochondria.
