Question

1-Give any two differences between archaea plasma membrane VS the bacterial and eukaryotic membrane.

2-What is difference between the L wall of gram-positive and negative bacteria?

3-Name any 2 structures that are outside the prokaryotic cell wall?

4- what is the difference between amphitrichous and peritrichous flagellar arrangement?

5- what are the general function of a cell wall in a eukaryotic cell?

Answer 1

Ans 1 )

• In archaea plasma membrane is in the L-isomeric form, while in bacteria and eukaryotes it is in D-isomeric form.
• Archea has an ether-linkage between the glycerol and the side chain of phospholipid, while the ester-linked lipids are found in bacteria and eukaryotes.

Ans 2) Cell walls of gram-positive bacteria are composed of thick layers of peptidoglycan. Gram-negative bacteria have cell walls with a thin layer of peptidoglycan. The cell wall also has an outer membrane with lipopolysaccharide molecules attached.

Ans 3) Pili, Flagella , Glycocalyx (capsule) are structures found outside the prokaryotic cell wall.

Ans 4) Amphitrichous bacteria have flagella on each of the polar ends or opposite to each other. In this one flagella on work and other is on rest. It also allows the bacteria to change their course rapidly in the reverse direction.

Peritrichous bacteria have flagella projecting in all directions (e.g., E. coli).It is a genetically-distinct trait that is used to characterize and distinguish bacteria. Ex:- Gram-negative rods, Pseudomonas has polar flagella to distinguish them from enteric bacteria, which have peritrichous flagella.

5.The cell wall is the protective, semi-permeable outer layer of a plant cell. A major function of the cell wall is to give the cell strength and structure, and to filter molecules that pass in and out of the cell