Question

Teichoic acid is present in which component of bacteria.
a. Cell wall
b. Plasma membrane
c. Outer membrane
d. Flagella

Answer 1

Hint: Teichoic acids are the copolymers of carbohydrates and glycerol phosphate or ribitol phosphate which are linked together through phosphodiester bonds. These acids are water-soluble polymers. Teichoic acids are substituted by sugars, amino sugars, and d-alanine.

Complete answer:
Gram-positive bacteria have the peptidoglycan layer which is made up of anionic glycopolymers known as wall teichoic acids. Teichoic acids have an important role in the determination of cell shape, cell division regulation, etc. Teichoic acids are present in the cell wall of Gram-positive bacteria such as Streptococcus, Staphylococcus, Bacillus, Corynebacterium, Clostridium, etc.

The plasma membrane consists of lipids and proteins but no acid is present in the plasma membrane.

The outer membrane contains lipopolysaccharide and glycolipid. It is present in Gram-negative bacteria.

Flagella consists of 20 proteins, which are divided into three substructures the filament, basal body, and the hook.

Hence, the correct answer is option (A).

Additional information:
- Teichoic acids along with their attached substituents plays a role in hydrophobicity and bacterial cell surface charge, by which binding of extracellular molecules gets affected.
- Teichoic acids protect bacteria from many adverse conditions and threats.
- This is a short linear anionic polysaccharide that is responsible for the negative charge of the cell surface.
- Teichoic acids are present only in the Gram-positive bacteria and are not present in Gram-negative bacteria.

Note: Teichoic acids are the polymers of glycerol phosphate or ribitol phosphate and carbohydrates, linked together via a phosphodiester bond. Teichoic acid has two forms of wall teichoic acid that is attached to the peptidoglycan wall and lipoteichoic acid that is attached to the lipid membrane. A major component of Gram-positive bacteria cell wall is Lipoteichoic acid which is related to various inflammatory diseases from minor skin diseases to severe diseases.