What are the components of the cell wall

The main components of the cell wall are cellulose, glucan, chitin and some other polysaccharide elements. The main function is to maintain the normal growth of cells in our body, while increasing the normal structure of cells. It has a powerful effect on all aspects of body transportation, so it brings full value to the human body, is absorbed and utilized by people's body, and the effects produced are also very rich.

composition

The middle lamella of the cell wall is basically composed of pectin.

If the pectin in plant tissues is broken down by pectinase, the cells will become discrete because the primary wall is composed of water, hemicellulose, pectin, cellulose, protein and lipids. The average values ​​of various components of the primary wall of the coleoptile, stem, leaf, and hair are shown in the table. Of the components that make up the cell wall, about 90% are polysaccharides, and about 10% are proteins, enzymes, and fatty acids. The polysaccharides in the cell wall are mainly cellulose, hemicellulose and pectin, which are polymerized by glucose, arabinose, galacturonic acid, etc. There is also a large amount of lignin in the secondary cell walls.

The extracellular matrix of animals is, in a sense, the cell wall, and its chemical composition is collagen, adhesion protein, aminopolysaccharides and proteoglycans.

The main component of bacterial cell walls is peptidoglycan.

The main components of fungal cell walls are chitin, cellulose, glucan, mannan, etc. These polysaccharides are polymers of monosaccharides.

Function

1. Maintain cell shape and control cell growth. The cell wall increases the mechanical strength of the cell and withstands the turgor pressure generated by the internal protoplasm due to the vacuole absorbing water, so that the cell has a certain shape. This not only protects the protoplasm, but also maintains the inherent morphology of organs and plants. In addition, the wall controls cell growth because the cell wall must relax and irreversibly stretch in order to expand and elongate.

2. Material transport and information transmission: The cell wall allows small molecules such as ions, polysaccharides and low molecular weight proteins to pass through, but blocks large molecules or microorganisms. Therefore, the cell wall is involved in a series of physiological activities such as material transport, reducing transpiration, preventing water loss (secondary wall, surface wax, etc.), and regulating plant water potential. The size of the pits or intercellular filaments on the cell wall is affected by the physiological age of the cell and the intensity of metabolic activity, so the cell wall has a regulatory effect on the transport of substances between cells. In addition, the cell wall is also the medium and pathway for the transmission of chemical signals (hormones, growth regulators, etc.) and physical signals (radio waves, pressure, etc.).

3. Defense and Resistance Some oligosaccharide fragments in the cell wall can induce the formation of phytoalexins. They also have regulatory effects on other physiological processes. Such oligosaccharide fragments with regulatory activity are called oligosaccharins. When a heptanoic acid oligosaccharide is applied to soybean cells, it activates the gene responsible for synthesizing antibiotics that inhibit mold growth and produces antibiotics. The functions of various oligosaccharides are complex and diverse. For example, some act as protease inhibitor inducers, playing a role in plant resistance to diseases and pests; some oligosaccharides can cause allergic death in plants, preventing pathogens from spreading further; and some oligosaccharides are involved in regulating the morphological construction of plants. In addition to being a structural component, extensin in the cell wall also has the function of preventing disease and resisting stress. For example, when a resistant cucumber variety is infected with a fungus, the content of hydroxyproline in its cell wall increases faster than that of a sensitive variety.