Question

Peptidoglycan is a polymer of millions of N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) sugars based on glucose molecules linked together in long chains cross-braced with four amino acids that link individual polymer chains together in a chain-link fence pattern. Layers of cross-braced NAG and NAM sheets are stacked vertically and held together by proteins with lipid anchors attached to the cell’s cytoplasmic membrane to form a scaffold of sugars and proteins that is able to hold the bacterial cell’s shape, even in response to extreme osmotic pressures. How would you expect a microbiology student to be able to describe the composition of peptidoglycan? What is the composition of the peptidoglycan layers found in the cell wall of bacteria?
Pick the answer that lists the composition of the bacterial cell wall.a. amino acids, NAG, and NAMb. NAG and NAMc. proteins and sugarsd. short amino acid chains, NAG, NAM, and some lipid proteins

Answer 1

Answer:

d) short amino acid chains, NAG, NAM, and some lipid proteins

Explanation:

Bacterial cell walls are made up of a rigid layer that is responsible for the resistance of the cell wall. This layer is called Peptidoglycan.

The basic structure of peptidoglycan is:

- A long chain of sugar derivatives, N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM). These two sugars are linked together by glycosidic bonds. Although these links are strong and make up the structural backbone, they are not sufficient to give the wall rigidity.

- The amino acids (L-alanine, D-alanine, D-glutamic, and Lysin) play an important role as peptide bridges that cross-braced the chains, joining the N-acetylmuramic molecules (NAM) together, giving greater rigidity to the structure.

Lipid proteins embedded in the wall with structure functions can also be found in the cell wall.