Question

Describe the most common targets of antibiotics in the bacterial cell.

Answer 1

Ans:- there are 3 main targets by which antibiotic kill bacteria, 1. inhibit cell wall synthesis. 2. inhibition od DNA or RNA synthesis 3. inhibition of protein synthesis.

1. inhibition of cell wall synthesis:- antibiotic like beta lactam works by inhibiting bacterial cell wall synthesis. it contains beta lactam ring in its structure. it inhibit synthesis of cell membrane  by preventing cross linking of Peptidoglycan. example. penicillin.

2. inhibition of DNA or RNA :- some antibiotic works by inhibiting DNA dependent RNA polymerase enzyme by which inhibit synthesis of nucleic acid , DNA and restrict proliferation of bacteria and kill them. antibiotic bind to RNA polymerase enzyme which is responsible for transcription and inhibit it.  for example rifamycin.

3. inhibition of protein synthesis:- this class of antibiotic bind to 70s ribosome and interfere with protein translation process. ribosome is site where protein synthesis from mRNA and tRNA takes place. bacterial ribosomes consist of 50s and 30s subunits. antibiotic binds to 50s subunit and inhibit peptide formation which in turn inhibit protein synthesis and kill bacteria for example:- chloramphenicol.