Question

Gram-negative and Gram-positive bacteria have cell membrane made up of:

• A. Peptidoglycan
• B. Cellulose
• C. Fats
• D. Chitin

Answer 1

Answer: (A)

• The cell wall of Gram-positive bacteria contains a thick peptidoglycan layer with teichoic acids. It can retain the gram stain and the bacteria appear purple because the thick layer of peptidoglycan traps the stain.
• The cell of Gram-negative bacteria contains a thin peptidoglycan layer without teichoic acids. Gram-negative bacteria appear bright pink or red because they have only a thin peptidoglycan layer sandwiched between two lipid layers.
• Cellulose is the major component of the cell wall of the plant. It provides strength and rigidity to the cell.
• Fats in the form of lipids form an integral component of the plasma membrane where it forms a bilayer.
• Chitin provides an integral component of the cell wall of fungi. It is a long-chain polymer of N-acetylglucosamine. It is the second most abundant homopolysaccharide.

So, the correct answer is option A.