Week 3

Question 1

What is a protazoa and a helminth?

Answer 1

A protazoa is a unicellular eukaryotic organism that causes disease. A helminth is a multicellular worm that causes disease.

Question 2

What is the difference between gram +ve and -ve?

Answer 2

Gram -ve has an inner and outer membrane whereas gram +ve only has an inner membran but a thick cell wall.

Question 3

Do gram +ve or -ve have techoic and lipo acid?

Answer 3

Gram +ve, part of cell wall.

Question 4

What are the roles or normal bacterial flora?

Answer 4

Stimulate immune response, aid digestion, produce vitamins and protection harmful bacteria.

Question 5

What are the targets for antibiotics?

Answer 5

Cell wall synthesis, cell membrane, protein synthesis, DNA synthesis and metabolic processes.

Question 6

What antibiotics target cell wall synthesis and how do they work?

Answer 6

B lactams work by binding to the transpeptidase enzyme that would normally form the cross links between the peptidoglycan chains.

Question 7

What antibiotics target nucleic acid synthesis and how do they work?

Answer 7

Fluroquinolones work by inhibiting DNA gyrase which would usually uncoil the DNA for replication.

Question 8

What are the mechanisms of intrinsic resistance?

Answer 8

Reducing the permeability of the membrane to the drug by reducing the number of porins. Also efflux pumps which actively remove the drug from the cell.

Question 9

What are the mechanisms of extrinsic resistance?

Answer 9

Modify or change the target so the drug can no longer bind. Modify the drug so it can’t bind, for example acetyltransferases and phosphotransferases.