A report on Cell wall

Diagram of the plant cell, with the cell wall in green.
Cell wall in multicellular plants – its different layers and their placement with respect to protoplasm (highly diagrammatic)
Molecular structure of the primary cell wall in plants
Photomicrograph of onion root cells, showing the centrifugal development of new cell walls (phragmoplast)
Chemical structure of a unit from a chitin polymer chain
Scanning electron micrographs of diatoms showing the external appearance of the cell wall
Illustration of a typical gram-positive bacterium. The cell envelope comprises a plasma membrane, seen here in light brown, and a thick peptidoglycan-containing cell wall (the purple layer). No outer lipid membrane is present, as would be the case in gram-negative bacteria. The red layer, known as the capsule, is distinct from the cell envelope.

Structural layer surrounding some types of cells, just outside the cell membrane.

- Cell wall
Diagram of the plant cell, with the cell wall in green.

72 related topics with Alpha

Overall

Fungus

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Any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms.

Any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms.

Fungal cell cycle showing Dikaryons typical of Higher Fungi
Omphalotus nidiformis, a bioluminescent mushroom
Bracket fungi on a tree stump
In 1729, Pier Antonio Micheli first published descriptions of fungi.
Armillaria solidipes
Mold growth covering a decaying peach. The frames were taken approximately 12 hours apart over a period of six days.
Polyporus squamosus
The 8-spore asci of Morchella elata, viewed with phase contrast microscopy
The bird's nest fungus Cyathus stercoreus
Prototaxites milwaukeensis (Penhallow, 1908)—a Middle Devonian fungus from Wisconsin
Main groups of fungi
Arbuscular mycorrhiza seen under microscope. Flax root cortical cells containing paired arbuscules.
Diagram of an apothecium (the typical cup-like reproductive structure of Ascomycetes) showing sterile tissues as well as developing and mature asci.
A pin mold decomposing a peach
The dark filaments are hyphae of the endophytic fungus Epichloë coenophiala in the intercellular spaces of tall fescue leaf sheath tissue
The lichen Lobaria pulmonaria, a symbiosis of fungal, algal, and cyanobacterial species
The plant pathogen Puccinia magellanicum (calafate rust) causes the defect known as witch's broom, seen here on a barberry shrub in Chile.
Gram stain of Candida albicans from a vaginal swab from a woman with candidiasis, showing hyphae, and chlamydospores, which are 2–4 µm in diameter.
Ergotamine, a major mycotoxin produced by Claviceps species, which if ingested can cause gangrene, convulsions, and hallucinations
Saccharomyces cerevisiae cells shown with DIC microscopy
The mold Penicillium rubens was the source of penicillin G.
A selection of edible mushrooms eaten in Asia
Stilton cheese veined with Penicillium roqueforti
Amanita phalloides accounts for the majority of fatal mushroom poisonings worldwide. It sometimes lacks the greenish color seen here.
Grasshoppers killed by Beauveria bassiana

A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls.

Archaea

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Archaea (singular archaeon ) constitute a domain of single-celled organisms.

Archaea (singular archaeon ) constitute a domain of single-celled organisms.

Archaea were found in volcanic hot springs. Pictured here is Grand Prismatic Spring of Yellowstone National Park.
The ARMAN are a group of archaea recently discovered in acid mine drainage.
Membrane structures. Top, an archaeal phospholipid: 1, isoprene chains; 2, ether linkages; 3, L-glycerol moiety; 4, phosphate group. Middle, a bacterial or eukaryotic phospholipid: 5, fatty acid chains; 6, ester linkages; 7, D-glycerol moiety; 8, phosphate group. Bottom: 9, lipid bilayer of bacteria and eukaryotes; 10, lipid monolayer of some archaea.
Bacteriorhodopsin from Halobacterium salinarum. The retinol cofactor and residues involved in proton transfer are shown as ball-and-stick models.
Sulfolobus infected with the DNA virus STSV1. Bar is 1 micrometer.
Archaea that grow in the hot water of the Morning Glory Hot Spring in Yellowstone National Park produce a bright colour
Methanogenic archaea form a symbiosis with termites.

Microbiologists tried to classify microorganisms based on the structures of their cell walls, their shapes, and the substances they consume.

Illustration of a Eukaryotic cell membrane

Cell membrane

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Biological membrane that separates the interior of all cells from the outside environment (the extracellular space) and protects the cell from its environment.

Biological membrane that separates the interior of all cells from the outside environment (the extracellular space) and protects the cell from its environment.

Illustration of a Eukaryotic cell membrane
Comparison of Eukaryotes vs. Prokaryotes
Examples of the major membrane phospholipids and glycolipids: phosphatidylcholine (PtdCho), phosphatidylethanolamine (PtdEtn), phosphatidylinositol (PtdIns), phosphatidylserine (PtdSer).
A detailed diagram of the cell membrane
Illustration depicting cellular diffusion
Diagram of the arrangement of amphipathic lipid molecules to form a lipid bilayer. The yellow polar head groups separate the grey hydrophobic tails from the aqueous cytosolic and extracellular environments.
Alpha intercalated cell
Diagram of the Cell Membrane's structures.

The cell membrane controls the movement of substances in and out of cells and organelles, being selectively permeable to ions and organic molecules. In addition, cell membranes are involved in a variety of cellular processes such as cell adhesion, ion conductivity and cell signalling and serve as the attachment surface for several extracellular structures, including the cell wall and the carbohydrate layer called the glycocalyx, as well as the intracellular network of protein fibers called the cytoskeleton.

Bacteria

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Bacteria (singular bacterium, common noun bacteria) are ubiquitous, mostly free-living organisms often consisting of one biological cell.

Bacteria (singular bacterium, common noun bacteria) are ubiquitous, mostly free-living organisms often consisting of one biological cell.

Rod-shaped Bacillus subtilis
Phylogenetic tree of Bacteria, Archaea and Eucarya. The vertical line at bottom represents the last universal common ancestor.
Bacteria display many cell morphologies and arrangements
The range of sizes shown by prokaryotes (Bacteria), relative to those of other organisms and biomolecules.
Structure and contents of a typical Gram-positive bacterial cell (seen by the fact that only one cell membrane is present).
An electron micrograph of Halothiobacillus neapolitanus cells with carboxysomes inside, with arrows highlighting visible carboxysomes. Scale bars indicate 100 nm.
Helicobacter pylori electron micrograph, showing multiple flagella on the cell surface
Bacillus anthracis (stained purple) growing in cerebrospinal fluid
Many bacteria reproduce through binary fission, which is compared to mitosis and meiosis in this image.
A culture of ''Salmonella
A colony of Escherichia coli
Helium ion microscopy image showing T4 phage infecting E. coli. Some of the attached phage have contracted tails indicating that they have injected their DNA into the host. The bacterial cells are ~ 0.5 µm wide.
Transmission electron micrograph of Desulfovibrio vulgaris showing a single flagellum at one end of the cell. Scale bar is 0.5 micrometers long.
The different arrangements of bacterial flagella: A-Monotrichous; B-Lophotrichous; C-Amphitrichous; D-Peritrichous
Streptococcus mutans visualised with a Gram stain.
Phylogenetic tree showing the diversity of bacteria, compared to other organisms. Here bacteria are represented by three main supergroups: the CPR ultramicrobacterias, Terrabacteria and Gracilicutes according to recent genomic analyzes (2019).
Overview of bacterial infections and main species involved.
Colour-enhanced scanning electron micrograph showing Salmonella typhimurium (red) invading cultured human cells
In bacterial vaginosis, beneficial bacteria in the vagina (top) are displaced by pathogens (bottom). Gram stain.
Antonie van Leeuwenhoek, the first microbiologist and the first person to observe bacteria using a microscope.

This wide variety of shapes is determined by the bacterial cell wall and cytoskeleton, and is important because it can influence the ability of bacteria to acquire nutrients, attach to surfaces, swim through liquids and escape predators.

Plant

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Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae.

Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae.

Green algae from Ernst Haeckel's Kunstformen der Natur, 1904.
A variaty of fungi species
Dicksonia antarctica, a species of tree fern
A petrified log in Petrified Forest National Park, Arizona
Range of pangaea glossopteris.
The leaf is usually the primary site of photosynthesis in plants.
There is no photosynthesis in deciduous leaves in autumn.
Plant cell structure
The Venus flytrap, a species of carnivorous plant.
Mechanical harvest of oats.
Melocactus plants being used as medicine.
Timber in storage for later processing at a sawmill
A rose espalier at Niedernhall in Germany.
Capitals of ancient Egyptian columns decorated to resemble papyrus plants. (at Luxor, Egypt)
Barbara McClintock (1902–1992) was a pioneering cytogeneticist who used maize (corn) to study the mechanism of inheritance of traits.
Musk Thistle are invasive species in texas.

All of these plants have eukaryotic cells with cell walls composed of cellulose, and most obtain their energy through photosynthesis, using light, water and carbon dioxide to synthesize food.

The arrangement of cellulose and other polysaccharides in a plant cell wall.

Cellulose

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Organic compound with the formula, a polysaccharide consisting of a linear chain of several hundred to many thousands of β linked D -glucose units.

Organic compound with the formula, a polysaccharide consisting of a linear chain of several hundred to many thousands of β linked D -glucose units.

The arrangement of cellulose and other polysaccharides in a plant cell wall.
Cellulose under a microscope.
A triple strand of cellulose showing the hydrogen bonds (cyan lines) between glucose strands
Cotton fibres represent the purest natural form of cellulose, containing more than 90% of this polysaccharide.
A strand of cellulose (conformation Iα), showing the hydrogen bonds (dashed) within and between cellulose molecules.

Cellulose is an important structural component of the primary cell wall of green plants, many forms of algae and the oomycetes.

Eukaryote

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Eukaryotes are organisms whose cells have a nucleus enclosed within a nuclear envelope.

Eukaryotes are organisms whose cells have a nucleus enclosed within a nuclear envelope.

The endomembrane system and its components
Simplified structure of a mitochondrion
Longitudinal section through the flagellum of Chlamydomonas reinhardtii
Structure of a typical animal cell
Structure of a typical plant cell
Fungal Hyphae cells: 1 – hyphal wall, 2 – septum, 3 – mitochondrion, 4 – vacuole, 5 – ergosterol crystal, 6 – ribosome, 7 – nucleus, 8 – endoplasmic reticulum, 9 – lipid body, 10 – plasma membrane, 11 – spitzenkörper, 12 – Golgi apparatus
This diagram illustrates the twofold cost of sex. If each individual were to contribute the same number of offspring (two), (a) the sexual population remains the same size each generation, where the (b) asexual population doubles in size each generation.
Phylogenetic and symbiogenetic tree of living organisms, showing a view of the origins of eukaryotes and prokaryotes
One hypothesis of eukaryotic relationships – the Opisthokonta group includes both animals (Metazoa) and fungi, plants (Plantae) are placed in Archaeplastida.
A pie chart of described eukaryote species (except for Excavata), together with a tree showing possible relationships between the groups
The three-domains tree and the Eocyte hypothesis
Phylogenetic tree showing a possible relationship between the eukaryotes and other forms of life; eukaryotes are colored red, archaea green and bacteria blue
Eocyte tree.
Diagram of the origin of life with the Eukaryotes appearing early, not derived from Prokaryotes, as proposed by Richard Egel in 2012. This view implies that the UCA was relatively large and complex.

Animal cells are distinct from those of other eukaryotes, most notably plants, as they lack cell walls and chloroplasts and have smaller vacuoles.

3D structure of cellulose, a beta-glucan polysaccharide

Polysaccharide

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Polysaccharides, or polycarbohydrates, are the most abundant carbohydrates found in food.

Polysaccharides, or polycarbohydrates, are the most abundant carbohydrates found in food.

3D structure of cellulose, a beta-glucan polysaccharide
Amylose is a linear polymer of glucose mainly linked with α(1→4) bonds. It can be made of several thousands of glucose units. It is one of the two components of starch, the other being amylopectin.
Some important natural structural polysaccharides
Schematic 2-D cross-sectional view of glycogen. A core protein of glycogenin is surrounded by branches of glucose units. The entire globular granule may contain approximately 30,000 glucose units.<ref>{{cite book | url = https://books.google.com/books?id=SRptlOx7yj4C | page = 12 | title = Exercise physiology: energy, nutrition, and human performance | vauthors = McArdle WD, Katch FI, Katch VL | edition = 6th | publisher = Lippincott Williams & Wilkins | date = 2006 | isbn = 978-0-7817-4990-9 }}</ref>
A view of the atomic structure of a single branched strand of glucose units in a glycogen molecule.

Cellulose is used in the cell walls of plants and other organisms and is said to be the most abundant organic molecule on Earth.

Onion (Allium cepa) root cells in different phases of the cell cycle (drawn by E. B. Wilson, 1900)

Cell (biology)

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Basic structural and functional unit of life forms.

Basic structural and functional unit of life forms.

Onion (Allium cepa) root cells in different phases of the cell cycle (drawn by E. B. Wilson, 1900)
Structure of a typical prokaryotic cell
Structure of a typical animal cell
Structure of a typical plant cell
Detailed diagram of lipid bilayer of cell membrane
A fluorescent image of an endothelial cell. Nuclei are stained blue, mitochondria are stained red, and microfilaments are stained green.
Deoxyribonucleic acid (DNA)
Human cancer cells, specifically HeLa cells, with DNA stained blue. The central and rightmost cell are in interphase, so their DNA is diffuse and the entire nuclei are labelled. The cell on the left is going through mitosis and its chromosomes have condensed.
Diagram of the endomembrane system
Prokaryotes divide by binary fission, while eukaryotes divide by mitosis or meiosis.
An outline of the catabolism of proteins, carbohydrates and fats
An overview of protein synthesis.
Within the nucleus of the cell (light blue), genes (DNA, dark blue) are transcribed into RNA. This RNA is then subject to post-transcriptional modification and control, resulting in a mature mRNA (red) that is then transported out of the nucleus and into the cytoplasm (peach), where it undergoes translation into a protein. mRNA is translated by ribosomes (purple) that match the three-base codons of the mRNA to the three-base anti-codons of the appropriate tRNA. Newly synthesized proteins (black) are often further modified, such as by binding to an effector molecule (orange), to become fully active.
Staining of a Caenorhabditis elegans highlights the nuclei of its cells.
Stromatolites are left behind by cyanobacteria, also called blue-green algae. They are the oldest known fossils of life on Earth. This one-billion-year-old fossil is from Glacier National Park in the United States.
Robert Hooke's drawing of cells in cork, 1665

Enclosing the cell is the cell envelope – generally consisting of a plasma membrane covered by a cell wall which, for some bacteria, may be further covered by a third layer called a capsule. Though most prokaryotes have both a cell membrane and a cell wall, there are exceptions such as Mycoplasma (bacteria) and Thermoplasma (archaea) which only possess the cell membrane layer. The envelope gives rigidity to the cell and separates the interior of the cell from its environment, serving as a protective filter. The cell wall consists of peptidoglycan in bacteria and acts as an additional barrier against exterior forces. It also prevents the cell from expanding and bursting (cytolysis) from osmotic pressure due to a hypotonic environment. Some eukaryotic cells (plant cells and fungal cells) also have a cell wall.

Peptidoglycan.

Peptidoglycan

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Peptidoglycan.
The structure of peptidoglycan. NAG = N-acetylglucosamine (also called GlcNAc or NAGA), NAM = N-acetylmuramic acid (also called MurNAc or NAMA).
Gram-positive cell wall
Penicillin binding protein forming cross-links in newly formed bacterial cell wall.

Peptidoglycan or murein is a polymer consisting of sugars and amino acids that forms a mesh-like peptidoglycan layer outside the plasma membrane of most bacteria, forming the cell wall.