A cell wall is a structural layer that surrounds some cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes rigid. Primarily, it provides the cell with structural support, shape, protection, and functions as a selective barrier.[1] Another vital role of the cell wall is to help the cell withstand osmotic pressure and mechanical stress. While absent in many eukaryotes, including animals, cell walls are prevalent in other organisms such as fungi, algae and plants, and are commonly found in most prokaryotes, with the exception of mollicute bacteria.
The composition of cell walls varies across taxonomic groups, species, cell type, and the cell cycle. In land plants, the primary cell wall comprises polysaccharides like cellulose, hemicelluloses, and pectin. Often, other polymers such as lignin, suberin or cutin are anchored to or embedded in plant cell walls. Algae exhibit cell walls composed of glycoproteins and polysaccharides, such as carrageenan and agar, distinct from those in land plants. Bacterial cell walls contain peptidoglycan, while archaeal cell walls vary in composition, potentially consisting of glycoprotein S-layers, pseudopeptidoglycan, or polysaccharides. Fungi possess cell walls constructed from the polymer chitin, specifically N-acetylglucosamine. Interestingly, diatoms have a unique cell wall composed of biogenic silica.[2]
^Romaniuk JA, Cegelski L (October 2015). "Bacterial cell wall composition and the influence of antibiotics by cell-wall and whole-cell NMR". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 370 (1679): 20150024. doi:10.1098/rstb.2015.0024. PMC 4632600. PMID 26370936.
^Rutledge RD, Wright DW (2013). "Biomineralization: Peptide-Mediated Synthesis of Materials". In Lukehart CM, Scott RA (eds.). Nanomaterials: Inorganic and Bioinorganic Perspectives. EIC Books. Wiley. ISBN 978-1-118-62522-4. Retrieved 2016-03-14.
A cellwall is a structural layer that surrounds some cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes...
The secondary cellwall is a structure found in many plant cells, located between the primary cellwall and the plasma membrane. The cell starts producing...
bacterial cell and a typical human cell (assuming both cells are spheres) : The cell envelope is composed of the cell membrane and the cellwall. As in other...
providing the cell with structural support, protection, and a filtering mechanism. The cellwall also prevents over-expansion when water enters the cell. The major...
mesh-like layer. Peptidoglycan serves a structural role in the bacterial cellwall, giving structural strength, as well as counteracting the osmotic pressure...
cells are the cells present in green plants, photosynthetic eukaryotes of the kingdom Plantae. Their distinctive features include primary cellwalls containing...
The cell envelope comprises the inner cell membrane and the cellwall of a bacterium. In gram-negative bacteria an outer membrane is also included. This...
the cell theory, Hooke misled the cell membrane theory that all cells contained a hard cellwall since only plant cells could be observed at the time. Microscopists...
movement of vesicles and organelles within the cell) and can be a template for the construction of a cellwall. Furthermore, it can form specialized structures...
consists of one or more cells surrounded by a tubular cellwall. In most fungi, hyphae are divided into cells by internal cross-walls called "septa" (singular...
humans. The cellwall and cell membrane of Methanobrevibacter smithii determine susceptibility to antibiotics and statins. The cellwall is composed of...
cells. Ordinary companion cells, which have smooth walls and few or no plasmodesmatal connections to cells other than the sieve tube. Transfer cells,...
Cell division is the process by which a parent cell divides into two daughter cells. Cell division usually occurs as part of a larger cell cycle in which...
(proplastids). Meristematic cells are packed closely together without intercellular spaces. The cellwall is a very thin primary cellwall. The term meristem was...
Microbiologists tried to classify microorganisms based on the structures of their cellwalls, their shapes, and the substances they consume. In 1965, Emile Zuckerkandl...
build intricate hard but porous cellwalls called frustules composed primarily of silica.: 25–30 This siliceous wall can be highly patterned with a variety...
and physical properties of their cellwalls. Gram-positive cells have a thick layer of peptidoglycan in the cellwall that retains the primary stain, crystal...
Plant cellwalls resist further water entry after a certain point, known as full turgor, which stops plant cells from bursting as animal cells do in the...
broadly based on the composition of their cellwall. Gram staining uses crystal violet to stain cellwalls, iodine (as a mordant), and a fuchsin or safranin...
nature of the cellwalls. This tissue system is present between the dermal tissue and forms the main bulk of the plant body. Parenchyma cells have thin primary...
Mycoplasma pneumoniae is a very small cellwall-less bacterium in the class Mollicutes. It is a human pathogen that causes the disease mycoplasma pneumonia...
The plant ECM includes cellwall components, like cellulose, in addition to more complex signaling molecules. Some single-celled organisms adopt multicellular...
Global Information