Question

an antibiotic that mimics the structure of aminoacul-tRNA and prevents chain elongation binds at the A site of both prokaryotic and eukaryotic ribosomes, accepting the peptide chain from the P site, and terminating protein synthesis

Answer 1

Antibiotics such as puromycin and tetracycline inhibit protein synthesis in ribosomes by binding to the A site and mimicking or blocking the binding of aminoacyl-tRNA.

Step-by-step explanation:

The topic of the student's question concerns the mechanism through which certain antibiotics prevent protein synthesis in prokaryotic and eukaryotic cells. Antibiotics such as puromycin and tetracycline can bind to the A site of ribosomes to inhibit protein synthesis. Puromycin acts by mimicking the structure of an aminoacyl-tRNA, which leads to premature chain termination, whereas tetracycline blocks the A-site, preventing the binding of aminoacyl-tRNA itself, which is essential for the translation process. Additionally, other antibiotics can have different mechanisms, like aminoglycosides impairing the proofreading ability of the ribosome and macrolides blocking peptide bond formation at the 50S subunit.