6- action of antibiotics

Question 1

bactericidal antibiotics

Answer 1

These antibiotics kill bacteria, often by destroying their cell walls.

Question 2

penicillin action

Answer 2

Inhibits the enzyme transpeptidase, which cross-links peptidoglycan chains in the bacterial cell wall.
Without these cross-links, the cell wall collapses, leaving the cell without a wall.

Question 3

penicillin result

Answer 3

The cell cannot withstand turgor pressure and bursts by osmotic lysis.

Question 4

penicillin effectiveness

Answer 4

Penicillin is most effective against Gram-positive bacteria, which rely on a thick peptidoglycan cell wall. It is less effective against Gram-negative bacteria, as the antibiotic cannot easily cross the outer lipopolysaccharide membrane of the Gram-negative cell walls to reach their peptidoglycan cell wall.

Question 5

penicillin spectrum

Answer 5

As penicillin only affects some bacteria, it is a narrow-spectrum antibiotic.

Question 6

bacteriostatic antibiotics

Answer 6

These antibiotics inhibit the growth and reproduction of bacteria but do not kill them.

Question 7

tetracycline action

Answer 7

Interferes with protein synthesis in 70s ribosomes by binding to them, blocking the attachment of tRNA.
This halts the production of nucleic acids and proteins, preventing the bacteria from growing and dividing.

Question 8

tetracycline effectiveness

Answer 8

As all bacteria have 70s ribosomes, it is effective against almost all bacteria.

Question 9

tetracycline spectrum

Answer 9

Due to its wide range of effectiveness, tetracycline is considered a broad-spectrum antibiotic.