AMS AFFECTING PROTIEN SYNTHESIS

2. Antimicrobial agents affecting protein
synthesis

5. Mode of action of antibiotics. Antibiotics can
inhibit the growth of bacteria by targeting the
bacterial cell wall or the cell membrane. Other
targets are the nucleic acid synthesis and the
protein synthesis. The latter is a process
performed by ribosomes , nucleoprotein
complexes which consist of a small and large
subunit (30S and 50S in bacteria, as shown in
the figure). Antibiotics can also act as
antimetabolites by inhibit ing the folate
metabolism (and consequently the DNA
synthesis) in a pathway involving
paraaminobenzoic acid (PABA) and two
precursors of folic acid, dihydrofolic acid (DHF)
and tetrahydrofolic acid (THF). Antibiotics can
inhibit DNA gyrase, an enzyme which modifies
the DNA conformation, playing a role in
replication and transcription. Class of
antibiotics involved in each mechanism are
shown in grey