Tag: cell wall and cell membrane

The mucopeptide is a peptidoglycan that is insoluble in nature. It is also called as murein. It is present in almost all bacterial cell walls. However, its percentage is higher in cell wall of gram positive bacteria than in cell wall of gram negative bacteria. 

It holds receptor molecules that help bacteria detect and respond to chemicals in their surroundings

Gram positive bacteria differs from Gram negative bacteria in having multiple layers of peptidoglycan. They have 20–30 nm thick and smooth cell wall. They contain 70-80% murein or peptidoglycan in cell wall. They do not have outer membrane like Gram negative bacteria, which have an outer LPS layer. Due to absence of outer LPS layer, Gram positive bacteria has two rings in basal body of flagellum, one attached to the plasma membrane and one attached to the peptidoglycan wall. They have prominent mesosomes. Mesosomes are folded invaginations of the plasma membrane.

Teichoic acids are found within the cell wall of most Gram-positive bacteria such as species in the genera Staphylococcus, Streptococcus, Bacillus, Clostridium, Corynebacterium, and Listeria, and appear to extend to the surface of the peptidoglycan layer.

Gram-negative bacteria are bacteria that do not retain the crystal violet stain during gram-staining procedure. Gram positive bacteria are bacteria that retain the crystal violet stain during gram staining procedure. Examples of Gram negative bacteria include Escherichia coli, Helicobacter pylori. Examples of Gram positive bacteria include Bacillus subtilis, Streptomyces coelicolor, Streptomyces orientalis (Ampycolatopsis orientalis).

• Glycocalyx or pericellular matrix is a carbohydrate-enriched coating of glycoprotein and a glycolipid that covers the cell membranes of few bacteria, epithelial cells and other cells. 
• It is mainly used in the recognition of the cell (distinguish between healthy and diseased cells) and also regulates the endothelial vascular tissues.
  
• So, the correct answer is 'Oligosaccharide part of glycolipids and glycoproteins'.

On the basis of composition of cell wall, the bacteria are classified into two groups, namely Gram positive and Gram negative bacteria. Cell wall of all bacteria is made up of peptidoglycan. The gram positive bacteria contains thick layer of peptidoglycan. However, Gram negative bacteria contains thin layer of peptidoglycan. Apart from this, it also contains an outer layer of lipopolysaccharide (LPS). Hence, the wall of Gram negative bacteria is two-layered.

• Cell recognition and adhesion occur due to biochemicals of cell membranes name glycoproteins and glycolipids.
  
• Glycocalyx or pericellular matrix is a carbohydrate-enriched coating of glycoprotein and a glycolipid that covers the cell membranes of few bacteria, epithelial cells and other cells. 
  
• It is mainly used in the recognition of the cell (distinguish between healthy and diseased cells) and also regulates the endothelial vascular tissues.
• So, the correct answer is 'Glycoproteins and glycolipids'.

The mucopeptide is a peptidoglycan that is insoluble in nature. It is also called as murein. It is present in almost all bacterial cell walls.