Question

antibacterial drugs that bind to the 70s ribosome inhibit prokaryotic protein synthesis. what organelle in a human cell might also be targeted, possibly accounting for some of the toxicity observed with some of these drugs?

Answer 1

Antibacterial drugs targeting the 70S ribosome can affect human mitochondria, which contain similar ribosomes, potentially leading to drug toxicity.

Step-by-step explanation:

Antibacterial drugs that bind to the 70S ribosome in prokaryotic cells to inhibit protein synthesis can sometimes also affect eukaryotic cells. This is due to the presence of mitochondria in human cells, which contain ribosomes similar to those of prokaryotes. Human mitochondria have 70S ribosomes, which can be unintentionally targeted by these drugs, contributing to their toxicity.

Despite the structural differences between bacterial 70S ribosomes and human cytoplasmic 80S ribosomes, the commonality in mitochondrial ribosomes can lead to side effects. This is because antibiotics like aminoglycosides, tetracyclines, and macrolides are designed to be selective, yet can sometimes influence mitochondrial protein synthesis, potentially causing toxicity in human cells.

For instance, aminoglycosides impair the proofreading ability of the bacterial ribosomal complex, which can have unintended effects on human mitochondrial ribosomes, leading to negative side effects like nephrotoxicity, neurotoxicity, and ototoxicity, due to their similarity to prokaryotic ribosomes.