The plant cell wall is a complex structure outside the cell membrane that provides structure and protection to the cell. It is made up of three main layers - the middle lamella, primary cell wall, and secondary cell wall. The primary cell wall is thin and elastic in young cells, and contains cellulose fibrils, hemicellulose, and pectin. As the cell matures, the secondary cell wall is deposited between the primary cell wall and cell contents. It is rigid and made mostly of cellulose and lignin. Together, the cell wall layers strengthen the plant body and play important roles in growth, differentiation, and defense.
CELL ORGANELLS
Plasma membrane
Protoplasm
Cell wall
Cell coat
Mitochondria
Endoplasmic reticulum
Golgi bodies
Ribosome
Nucleus
CONCLUSION
REFRENCE
All living organisms on Earth are divided in pieces
called cells. There are smaller pieces to cells that
include proteins and organelles. There are also larger
pieces called tissues and systems. Cells are small
compartments that hold all of the biological
equipment necessary to keep an organism alive and
successful on Earth.
CELL ORGANELLS
Plasma membrane
Protoplasm
Cell wall
Cell coat
Mitochondria
Endoplasmic reticulum
Golgi bodies
Ribosome
Nucleus
CONCLUSION
REFRENCE
All living organisms on Earth are divided in pieces
called cells. There are smaller pieces to cells that
include proteins and organelles. There are also larger
pieces called tissues and systems. Cells are small
compartments that hold all of the biological
equipment necessary to keep an organism alive and
successful on Earth.
Charles Overton was the first one to suggest that cell membrane is made up of lipids. In the last years of the 19th century Overton did experimental work, allowing the distinction to be drawn between the cell wall of plants and their cytoplasmic membrane.He studied the permeability of a range of biological
materials to around 500 chemical compounds. In 1900, Overton proposed a biomembrane model "Overton Biomembrane Model" which stated that biomembranes are made up of lipids. He gave this statement on the basis of observation of transport of lipid soluble substances across the biomembranes.
Minimize seed deterioration during it’s storage of orthodox or recalcitrant s...AKHILRDONGA
PG major SEMINAR on minimize seed deterioration during its storage of orthodox or recalcitrant seed ppt file delivered by Pratik Bhankhar (M.Sc. Seed Science and Technology) at C. P. College of Agriculture, S. D. Agricultural University, Sardarkrushinagar.
it contains How to minimize the seed deterioration during its storage.
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Charles Overton was the first one to suggest that cell membrane is made up of lipids. In the last years of the 19th century Overton did experimental work, allowing the distinction to be drawn between the cell wall of plants and their cytoplasmic membrane.He studied the permeability of a range of biological
materials to around 500 chemical compounds. In 1900, Overton proposed a biomembrane model "Overton Biomembrane Model" which stated that biomembranes are made up of lipids. He gave this statement on the basis of observation of transport of lipid soluble substances across the biomembranes.
Minimize seed deterioration during it’s storage of orthodox or recalcitrant s...AKHILRDONGA
PG major SEMINAR on minimize seed deterioration during its storage of orthodox or recalcitrant seed ppt file delivered by Pratik Bhankhar (M.Sc. Seed Science and Technology) at C. P. College of Agriculture, S. D. Agricultural University, Sardarkrushinagar.
it contains How to minimize the seed deterioration during its storage.
BREEDING FOR VIRUS RESISTANCE IN PULSES.pptxAKHILRDONGA
PG major SEMINAR on BREEDING FOR VIRUS RESISTANCE IN PULSES ppt file delivered by Dheeraj Bamaniya from M.Sc. (Genetics and Plant breeding) in C. P. college of agriculture, S. D. Agricultural University, Sardarkrushinagar. it Contains how to develop virus-resistant varieties in pulse crops
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PG SEMINAR on Role of Biotechnological Approaches in Underutilized Tropical Fruit Improvements ppt file delivered by Hardiksinh Chavda (M.Sc. in Plant molecular biology and biotechnology) at C. P. College of Agriculture, S. D. Agricultural University, Sardarkrushinagar.
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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.
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/
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.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
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.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
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.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
2. CELL WALL
Cell wall was first observed and named simply as a "wall" by Robert
Hooke in 1665.
In 1804, Karl Rudolphi and J.H.F. Link proved that cells have
independent cell walls.
Cell wall is comparatively thick and rigid envelope that surrounds
plant cells.
It is considered as secretion of protoplasm the living portion of the
cell. It is laid down in the telophase stage of the cell division, when the
pectin rich vesicles of golgi bodied (about 2.0 m) in diameter, migrate
to the equatorial region of the cell.
3. Cell wall is synthesized later to complete cytokinesis.
The cell wall is a protective layer outside the cell membrance that
also provides support for the cell's structure.
A cell wall refers to the rigid and semi permeable protective layer in
some types of cells.
This outer covering is located next to the plasma membrane of the
cells of plants, algae, bacteria and fungi.
5. CELL WALL LAYER
The plant cell wall is differentiated into three layers as follows.
1. Middle lammella,
2. Primary cell wall,
3. Secondary cell wall.
6. 1. MIDDLE LAMELLA
Middle lamella is the cementing substance between two adjacent
cells.
It is made of pectic compounds, chiefly calcium and magnesium
pectate. Pectic substances are the mixture of polygalacturon (D-
galacturonic acid) and polysaccharides (netural sugar).
Sometimes lignin and hemicellulose also are found in the middle
lamella.
In mature ripe fruits, the softening in due to the dissolution of middle
lamella by the action of pectolytic enzymes.
7. 2. PRIMARY CELL WALL
Primary cell wall is formed when cellulose fibrils produced by
protoplasm, are accumulated in concentric rows on either side of
middle lamella.
It is thin and elastic in young enlarging cells and becomes thick and
rigid during cell maturity.
It is capable of growth and expansion.
The backbone of primary cell wall is formed by the cellulose fibrils.
The matrix is composed of hemicellulose, pectin compounds, lipids,
structural proteins.
9. 3. SECONDARY CELL WALL
Secondary cell wall is laid down between the primary cell wall and
protoplast and is formed when the cell mature.
It is formed by the deposition of cellulose on primary cell wall.
It is inelastic and rigid.
It is chiefly composed of cellulose and other non cellulosic
substances like lignin, fats and proteins.
10. The secondary cell wall commonly has three layers S1,S2, and S3
e.g, outer layer, the middle layer and the inner layer.
11. STRUCTURAL ORGANIZATION OF CELL
WALL
The cell wall is structurally thought as a fine interwoven network of
cellulose strands.
According to siegel (1962) elementary fibrils or micelles are the
smallest structural units of the cell wall.
They are composed of appoximately 100 individual cellulosic chains
with a cross sectional area of about 3000Angsrom.
The matrix
It is the ground substance in which fibrils are embedded. It is
amorphous and is deposited with pectin, or lignin hemicelluloses.
12. The fibrils
The fibrils are composed of cellulose. The cellulose molecules are polymer
of disaccharide cellobiose having approx. 3000 glucose unit which are
arranged in linear order.
The cellulose molecules of the primary wall are arranged along the
longitudinal axis of the cells in definitely organized longitudinal bundles.
These bundles known as macrofibrils.
Plasmodesmata
On maturation, certain fibrous structure develop called plasmodesmata.
Which the adjacent cell are in communication with each other.
Plasmodesmata are also called tonofibrils.
13. COMPOSITION OF CELL WALL
1.Cellulose:
It provides shape and strength to the cell wall. It composes 20-30 %
of the dry weight of primary wall and accounts 40-90% of the dry
weight of secondary wall.
2.Pectins:
They are group of polysaccharides, which are rich in galacturonic
acid, rhamnose, arabinose and galactose. Pectins are present in high
concentration in the middle lamella where they presumably serve the
function of cementing adjacent cells together.
14. 3. Hemicelluloses:
These are matrix polysaccharides built up of a variety of different sugars.
They differ in different species and in different cell types.
Xylan:
It typically makes up roughly 5% of primary cell wall and 20% of
secondary cell wall in dicots. This hemi cellulosic polysaccharide is linked
with xylose and arabinose.
4. Proteins:
Different varieties of protein are present in the cell wall, most of which
are linked with carbohydrate forming glycoprotein. The cell wall glycoprotein
extensin contains an unusual amino acid hydroxyproline (about 40%), which
is generally absent from the protoplast. Extensins are present in the primary
cell walls of dicots making up one to ten percent of the wall.
15. FUNCTION OF CELL WALL
They determine the morphology, growth and development of plant cells.
They protect the protoplasm from invasion by viral, bacterial and fungal
pathogens.
They withstand the turgor pressure which develops within the cells due to
high osmotic pressure.
It helps the aerial portion of the land plants to tolerate gravitational forces.
It being permeable, helps in the transport of materials in and out of the cell.
It provides a definite shape to the cell and protects internal organelles from
external shocks.
16. ORIGIN OF CELL WALL
1) Formation of matrix
2) Synthesis and orientation of cellulose microfibrils
17. Growth of the plant cell wall
Daniel J. Cosgrove (2005). Nature reviews molecular cell biology. 6(11): 850-861.
Summary:
Plant cells encase themselves within a complex polysaccharide wall, which
constitutes the raw material that is used to manufacture textiles, paper,
lumber, films, thickeners and other products.
The plant cell wall is also the primary source of cellulose, the most
abundant and useful biopolymer on the Earth.
The cell wall not only strengthens the plant body, but also has key roles in
plant growth, cell differentiation, intercellular communication, water
movement and defence.
Recent discoveries have uncovered how plant cells synthesize wall
polysaccharides, assemble them into a strong fibrous network and regulate
wall expansion during cell growth.
18. CELL MEMBRANE
The cell membrane (also called the plasma membrane or
plasmalemma) is a biological membrane separating the interior of a
cell from the outside environment.
It appears in thin sections with the electron microscope as structure
about 7.5-10 nanometers thick.
Term coined by C. Nageli and C. Cramer in 1855, and Plasmalemma
coined by J. Q. Plowe in 1931.
20. MODELS OF CELL MEMBRANE
Sandwich model:
It is proposed by Danielli and Dayson in 1935.
In this model a lipid bilayer was coated on its either side with
proteins.
Mutual attraction between the hydrocarbon chains of the lipids and
electrostatic force between the protein and the head of lipid were
thought to maintain the stability of the membrane.
They predicted the lipid bilayer to be about 6.0 nm in thickness, and
each of the protein layer of about 1.0 nm thickness, giving a total
thickness of about 8.0 nm.
21.
22. Unit membrane model:
Using evidence from various electron micrographs, Robertson in
1960, proposed the unit membrane hypothesis.
This hypothesis states that all cellular membranes have an identical
trilaminar structure (or dark-light- dark or railway track pattern, see
Thorpe, 1984).
However, thickness of the unit membrane has been found to be greater
in plasma membrane (10 nm) than in the intracellular membranes of
endoplasmic reticulum or Golgi apparatus (i.e., 5 to 7 nm).
23.
24. Fluid mosaic model:
S. J. Singer and G. L. Nicolson (1972) suggested the widely accepted
fluid mosaic model of biological membranes. According to this model,
the plasma membrane contains a bimolecular lipid layer, both surfaces
of which are interrupted by protein molecules.
Proteins occur in the form of globular molecules and they are dotted
about here and there in a mosaic pattern. Some proteins are attached at
the polar surface of the lipid (i.e., the extrinsic proteins); while others
(i.e., integral proteins) either partially penetrate the bilayer or span the
membrane entirely to stick out on both sides (called transmembrane
proteins).
25. Further, the peripheral proteins and those parts of the integral proteins
that stick on the outer surface (i.e., ectoproteins) frequently contain
chains of sugar or oligosaccharides (i.e., they are glycoproteins).
Likewise, some lipids of outer surface are glycolipids.
The fluid-mosaic membrane is thought to be a far less rigid than was
originally supposed. In fact, experiments on its viscosity suggest that it
is of a fluid consistency rather like the oil, and that there is a
considerable sideways movement of the lipid and protein molecules
within it.
26. On account of its fluidity and the mosaic arrangement of protein
molecules, this model of membrane structure is known as the “fluid
mosaic model” (i.e., it describes both properties and organization of
the membrane).
27. CHEMICAL COMPOSITION OF PLASMA
MEMBRANE
The basic structural framework is the lipid bilayer.
1)Lipids
2)Proteins
3)Carbohydrate.
1) MEMBRANE LIPIDS:
75% - phospholipids
20% - cholesterol
5% - glycolipids.
28. Mostly lipids are Amphipathic having both polar & nonpolar parts.
Acts as permeability barriers. Essential for the maintenance of fluidity
of membranes.
Phospholipids
"Head" - Polar part-phosphate group
"Tail" - Non polar part - long chain
fatty acids
29. Cholesterol molecules are weakly amphipathic & are interspersed
among the other lipids in both layers of the membrane.
Glycolipids present only in the membrane layer that faces the
extracellular fluid.
30. MEMBRANE PROTEIN
Two types of proteins are present in membrane
1) Integral proteins 2) peripheral proteins
Integral proteins extend through the lipid bilayer are firmly
embedded in it.
Most integral proteins are transmembrane proteins.
Peripheral proteins are not embedded in the membrane.
They associate more loosely with the polar heads of membrane lipids
at the inner or outer surface of the membrane.
Many membrane proteins are glycoproteins.
32. MEMBRANE CARBOHYDRATE
Carbohydrate are covalently bound to lipids to form glycolipids and to
the protein to form glycoproteins.
These are mostly
• Glucose
• Galactose
• Mannose
• N-acetyl glucosaine
• N-acetyl galactosamine
33. TRANSPORT ACROSS CELL
MEMBRANE
1) Passive transport
Simple diffusion
Facilitated diffusion
2) Active transport
Primary Active Transport
Secondary Active Transport
3) Bulk Transport
Exocytosis
Endocytosis
34. Active Transport
1) Primary Active Transport.
Transport against concentrate gradient in which energy is used
directly. It is carrier mediated.
Example -sodium-potassium pump, calcium pump.
2) Secondary Active Transport
Transport against concentrate gradient in which energy is used
indirectly.
The transport of two or three molecules are coupled.
This transport is coupled with Na-KATPase, that requires the ATP. It
occurs by symport and antiport.
35. Bulk Transport
Also called transport by vesicle formation. It involves formation of
membrane bound vesicles. It involves transport of macromolecule.
1) Exocytosis
Expulsing out of molecules from the cell.
2) Endocytosis
Engulfing large molecules by the cell.
36. FUNCTION OF CELL MEMBRANE
Keeps a cell intact
Protective barrier
Regulate transport in & out of cell (selectively permeable)
Small lipid-soluble molecules, e.g. oxygen and carbondioxide can pass easily
Water can freely cross the membrane
Ions and large molecules cannot cross without assistance
Allow cell recognition
Provide anchoring sites for filaments of cytoskeleton
Provide a binding site for enzymes
Interlocking surfaces bind cells together (junctions)
Contains the cytoplasm (fluid in cell)
37. ORIGIN OF CELL MEMBRANE
All cellular membranes grow from pre- existing membranes which act
as templates for the addition of new precursors.
All cells divide, daughter cells receive a full complement of
membrane systems which undergo growth until the next division, to be
passed on to subsequent progeny.
Meanwhile the molecules within the membrane undergo continuous
replacement.
38. The basic structure and dynamics of cell membranes: An update of
the Singer–Nicolson model
Felix M. Goni (2014). Biochimica et Biophysica Acta 1838 (2014) pp.1467–1476.
Summary
The fluid mosaic model of Singer and Nicolson (1972) is a
commonly used representation of the cell membrane structure and
dynamics. However a number of features, the result of four decades of
research, must be incorporated to obtain a valid, contemporary version
of the model. Among the novel aspects to be considered are:
(i) the high density of proteins in the bilayer, that makes the bilayer a
molecularly “crowded” space, with important physiological
consequences;
(ii) the proteins that bind the membranes on a temporary basis, thus
establishing a continuum between the purely soluble proteins, never in
contact with membranes, and those who cannot exist unless bilayer-
bound;
39. (iii) the progress in our knowledge of lipid phases, the putative
presence of non-lamellar intermediates in membranes, and the role of
membrane curvature and its relation to lipid geometry,
(iv) the existence of lateral heterogeneity (domain formation) in cell
membranes, including the transient microdomains known as rafts, and
(v) the possibility of transient and localized transbilayer (flip-flop)
lipid motion.
40. REFERENCES
Verma, P. S. and Agarwal, V. K. (2005). CELL BIOLOGY, GENETICS,
MOLECULAR BIOLOGY, EVOLUATION AND ECOLOGY.
Page no. 112-153.