This presentation intends to explore the communication of the cell within and others for sustainability along the regulation mechanisms by the cellular neural networks and others to sing the song of the life.
Cell, in biology, the basic membrane-bound unit that contains the fundamental molecules of life and of which all living things are composed. A single cell is often a complete organism in itself, such as a bacterium or yeast. Other cells acquire specialized functions as they mature. These cells cooperate with other specialized cells and become the building blocks of large multicellular organisms, such as humans and other animals. Although cells are much larger than atoms, they are still very small. The smallest known cells are a group of tiny bacteria called mycoplasmas; some of these single-celled organisms are spheres as small as 0.2 μm in diameter (1μm = about 0.000039 inch), with a total mass of 10−14 gram—equal to that of 8,000,000,000 hydrogen atoms. Cells of humans typically have a mass 400,000 times larger than the mass of a single mycoplasma bacterium, but even human cells are only about 20 μm across. It would require a sheet of about 10,000 human cells to cover the head of a pin, and each human organism is composed of more than 30,000,000,000,000 cells.
similarities and differences between cells
similarities and differences between cells
Basic similarities between cells and ways cells may vary depending on their function.
See all videos for this article
This article discusses the cell both as an individual unit and as a contributing part of a larger organism. As an individual unit, the cell is capable of metabolizing its own nutrients, synthesizing many types of molecules, providing its own energy, and replicating itself in order to produce succeeding generations. It can be viewed as an enclosed vessel, within which innumerable chemical reactions take place simultaneously. These reactions are under very precise control so that they contribute to the life and procreation of the cell. In a multicellular organism, cells become specialized to perform different functions through the process of differentiation. In order to do this, each cell keeps in constant communication with its neighbours. As it receives nutrients from and expels wastes into its surroundings, it adheres to and cooperates with other cells. Cooperative assemblies of similar cells form tissues, and a cooperation between tissues in turn forms organs, which carry out the functions necessary to sustain the life of an organism.
This presentation intends to explore the communication of the cell within and others for sustainability along the regulation mechanisms by the cellular neural networks and others to sing the song of the life.
Cell, in biology, the basic membrane-bound unit that contains the fundamental molecules of life and of which all living things are composed. A single cell is often a complete organism in itself, such as a bacterium or yeast. Other cells acquire specialized functions as they mature. These cells cooperate with other specialized cells and become the building blocks of large multicellular organisms, such as humans and other animals. Although cells are much larger than atoms, they are still very small. The smallest known cells are a group of tiny bacteria called mycoplasmas; some of these single-celled organisms are spheres as small as 0.2 μm in diameter (1μm = about 0.000039 inch), with a total mass of 10−14 gram—equal to that of 8,000,000,000 hydrogen atoms. Cells of humans typically have a mass 400,000 times larger than the mass of a single mycoplasma bacterium, but even human cells are only about 20 μm across. It would require a sheet of about 10,000 human cells to cover the head of a pin, and each human organism is composed of more than 30,000,000,000,000 cells.
similarities and differences between cells
similarities and differences between cells
Basic similarities between cells and ways cells may vary depending on their function.
See all videos for this article
This article discusses the cell both as an individual unit and as a contributing part of a larger organism. As an individual unit, the cell is capable of metabolizing its own nutrients, synthesizing many types of molecules, providing its own energy, and replicating itself in order to produce succeeding generations. It can be viewed as an enclosed vessel, within which innumerable chemical reactions take place simultaneously. These reactions are under very precise control so that they contribute to the life and procreation of the cell. In a multicellular organism, cells become specialized to perform different functions through the process of differentiation. In order to do this, each cell keeps in constant communication with its neighbours. As it receives nutrients from and expels wastes into its surroundings, it adheres to and cooperates with other cells. Cooperative assemblies of similar cells form tissues, and a cooperation between tissues in turn forms organs, which carry out the functions necessary to sustain the life of an organism.
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.
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.
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.
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 .
Nutrition is the science that deals with the study of nutrients and their role in maintaining human health and well-being. It encompasses the various processes involved in the intake, absorption, and utilization of essential nutrients, such as carbohydrates, proteins, fats, vitamins, minerals, and water, by the human body.
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.
3. Why cell Junctions are formed?
• Cells do not like to live in isolation.
• Formation of multicellular organisms require specific interaction
between cells to hold the cells together and to communicate in order
to coordinate activities.
• Cell junctions are structures where long term, permanent association
between cells are established.
• Mainly 3 types of cell junctions
1. Occluding junctions
2. Anchoring junctions
3. Communicating junctions
3
6. 1. Occluding junctions / Tightjunctions
• A cell-cell junction
• Seals cells together in an epithelium .(Skin,
intestinal lining.)
• No space between plasma membranes of adjacent cells.
• Prevents even small molecules from leaking from one side of the
sheet to other .
• Block lateral movement of lipids & membrane proteins to keep a
cell polarized.
6
7. Functions
• Gives strength and stability to the cell.
• Fencing(Protective) function.
• Maintains cell polarity.
• Prevents flow of glucose between cells.
• Selectively permeable for ions.
7
9. a.Adherence junction
• A cell-cell junction.
• Cadherins are the cell adhesion molecules.
• Interaction of Cadherin is Calcium dependent.
• Cadherin attach with actin filament via specific adaptors like alpha
catenin, beta catenin etc.
• When there is enough Ca2+ Cadherin get attached to nearby cells &
form adherence junctios.
9
10. b.Desmosomes
• They are bipartite structures of apposing cell membranes.
• An attachment plaque on the cytoplasmic side anchors
tonofilaments which are intermediate filaments.
• Desmosomes form strong points of adhesion between cells
in a tissue such that 2 adjoining cells are separated by a thin
space of 25-35 nm.
• Cell adhesion molecules are Desmosomal Cadherins.
10
11. c.Hemidesmosomes
• Connect a cell, through a plaque to the basal lamina (ECM) by
integrins.
• As in Desmosomes, Hemidesmosomes interact with tonofilament-
intermediate filaments .
• Hemidesmosomes occur at most basal surface of stratified squamous
epithelia, where the superficial layer lack junctional complexes & the
basal cells are exposed to the underlying cytoplasm.
11
12. Functions
• Provide firm structural & mechanical attachment between 2 cells or
between a cell and ECM.
• Responsible for structural integrity of tissue.
• Developing polarity in Neural tube closure.
• Imp .in pancreatic branching.
12
13. Adherens junction & Cancerformation
• In tumour cells Adherens junction are not present.
• Adherens junction proteins are heavily down regulated .
• So, tumour cells easily gets dissociated, travel through blood supply &
reach secondary organs via metastasis.
• Over expression of Cadherin protein prevent them to metastasize.
13
14. 3.Communicating junctions (Gap junctions )
First discovered in
myocardium &nerve
cells because of
their properties of
electrical
transmission
between adjacent
cells.
14
15. Communicating junctions (Gap junctions)
• A Cell-cell junction .
• Clusters of intercellular channels, that allow direct diffusion of
ions& small molecules between adjacent cells.
• Present in heart, basal part of epithelial cell of intestinal
mucosa…etc.
• As sites of electron- coupling (reduced resistance to ion flow) ,it
is the only type of junction mediating flow of current between
cells.
• Junctional unit - Connexins
• 6 proteins called Connexins form a Connexon.
• 2 connexons end to end form a 1.5nm channel between 2 cells.
15
16. Functions
• Important in intercellular communication
and coordination.
• Allows passage of ions, cyclic AMP, amino
acids &other small molecules.
• Synchronizingbeat of heart muscle cells.
• Rapid propagation of action potential
from one cell to another.
• Exchange of chemical messages between
cells.
• Cancer cells generally do not have gap
junctions,so that cells fail to communicate
their mitotic activity to each other, which
may explain their uncontrolled growth.
16
17. Plasmodesmata
• Adherence between plant cells –
mediated by their cell walls rather than
by transmembrane proteins.
• Middle lamella –a pectin rich region of
cell wall acts as a glue to hold adjacent
cells together.
• Plant cells do not require formation of
cytoskeletal links(desmosomes &
Adherens junctions of animal cells)- due
to rigidity of plant cell wall.
• Function is analogous to Gap junctions.
17
18. • An extension of smooth
Endoplasmic reticulum passes
through the pore, leaving a ring of
surrounding cytoplasm – through
which ions and small molecules
are able to pass.
• Plasmodesmata are dynamic
structures that can open and
close in response appropriate
stimuli.
• Regulated passage of
macromolecules is possible.
18
