Question

Penicillin halts bacterial infections:

Select one:
a. By stimulating a person's immune system
b. By damaging the cell membrane
c. By causing the DNA of a bacterium to mutate
d. By interfering with the construction of the cell wall
e. All of the above are correct

Answer 1

Penicillin combats bacterial infections by inhibiting the enzyme needed for building their cell walls, leading to bacterial cell destruction due to osmotic pressure. Human cells are not affected as they do not have cell walls.

Step-by-step explanation:

Penicillin halts bacterial infections by interfering with the construction of the cell wall. This antibiotic works specifically by inhibiting the enzyme transpeptidase, which is essential for the biosynthesis of bacterial cell walls, especially in peptidoglycan synthesis. Without a proper cell wall, bacteria are subjected to osmotic pressure, which causes them to burst. It is noteworthy that human cells are unaffected by penicillin because they lack cell walls, which ensures selective toxicity against bacteria.

The correct answer to the question would, therefore, be 'By interfering with the construction of the cell wall.' Human immunity is not directly stimulated, the cell membrane is not damaged, nor is the DNA mutated by penicillin; hence, other options are incorrect.