Answer to Question #274229 in Microbiology for fati

Question

1.    Compare between the structure of the ribosomes in prokaryotic and eukaryotic cells? (1 point):  

2. Explain how exo-enzymes produced by bacteria which digest different macro-molecules in the surrounding environment, won’t digest these molecules inside the bacterial cells? (1 point):  

3. In the peptidoglycan layer of bacterial cells: give a reason why the tetrapeptide side chain is only binding to the NAM molecule and not to the NAG?

4.   Two types of prokaryotic cells can be distinguished: bacteria and archaea. How do these cells differ from each other? Compare their cell wall structure, patterns of cytoplasmic membranes and ribosomal entities and 16S-rRNA? (1.5 points): 

5.Compare between the structure of cell wall in prokaryotic and eukaryotic cells?

Answer 1

1.

The key difference between prokaryotic and eukaryotic ribosomes is that the prokaryotic ribosomes are 70S particles composed of 50S large subunit and 30S small subunit while the eukaryotic ribosomes are 80S particles composed of 60S large subunit and a 40S small subunit.

2.

exo enzymes are enzymes produced by bacteria and fungi , which helps in breaking down of macromolecules and helps in absorbing the small digested molecules . 

these exoenzymes are produced inside the bacteria and are secreted outside environment . inside the bacterial cells, these enzymes are usually inactive , as the optimal conditions for activity of the enzymes is not provided . 

the intracellular environment is usually acidic in nature and these enzymes wont work well under these conditions . 

hence these enzymes are not degrading any intracellular macromolecules .

3.

In any bacterial cell wall structure, it is made of peptidoglycan in which the glycan part of has two alternating sugars. They are NAM( N- acetyl muramic acid) and NAG( N-acetyl glucosamine).

4.

Bacteria and Archaea differ in the lipid composition of their cell membranes and the characteristics of the cell wall.

5.

Most prokaryotic cells have a rigid cell wall that surrounds the plasma membrane and gives shape to the organism. In eukaryotes, vertebrates don't have a cell wall but plants do