Final answer:
Bacterial ribosomes are the target of antibiotics that inhibit host cell protein synthesis. Tetracyclines and chloramphenicol are examples of such inhibitors that block tRNA attachment and peptidyl transfer, respectively, affecting the 70S ribosome structure unique to prokaryotes.
Step-by-step explanation:
Part of bacteria that inhibits host cell protein synthesis primarily involves the bacterial ribosomes, which are the sites where protein synthesis occurs. In bacteria, these ribosomes have a distinct 70S structure, different from the 80S ribosomes found in eukaryotic cells, making them a selective target for antibacterial drugs.
Specific antibiotics, such as tetracyclines, bind to the bacterial ribosome in a way that blocks the attachment of tRNA to the ribosome's A site, thus inhibiting the codon-anticodon interaction necessary for protein synthesis. Chloramphenicol is another example that blocks peptidyl transfer during this process. While these antibiotics can inhibit protein synthesis in eukaryotic cells as well, the mechanisms or conditions required for such effects within host cells are generally less likely to occur due to differences in cellular uptake and differences in ribosome structure.