Question

You are working in a laboratory producing new antibiotics for human and veterinary use. One compound with potential value inhibits the action of prokaryotic ribosomes. The compound, however, was shown to inhibit the growth of animal cells in culture. What is one possible explanation for its effect on animal cells?

Applications

A research laboratory in pharmaceutical company is studying environmental factors that would inhibit the growth of Archaea. One question they have is if adding of antibiotic penicillin would be effective in controlling their growth. Explain to your best knowledge the probable results of an experiment in which penicillin is added to a culture of Archaea?

Critical Thinking

Most medically used antibiotics interfere with either peptidoglycan synthesis or ribosome function. Why do you think the cytoplasmic (cell) membrane would be a POOR target for antibacterial medications?

Focus Point

Compare and describe the following Prokaryotic and Eukaryotic cell structure/functions:

General Characteristics:

Size:

Cell Division:

Structures:

Cell Membrane:

Nucleus:

Functions:

Transport

Answer 1

An antibiotic that inhibits prokaryote growth through ribosome inhibition would also effect animal Cells' growth since animal cells also use ribosome for protein synthesis. Although the antibiotics would have a higher affinity for prokaryotic ribosomes but on the basis of structural similarity they bind eukaryotic ribosomes and inhibit protein synthesis in animal cells.

The mode of action of penicillin is through inhibition of cross linking of peptide chain by deactivating enzyme transpeptidase. This is the first step in peptidoglycan wall synthesis in bacteria. Archae on the other hand do not have a peptidoglycan cell wall and thus penicillin does not act on archae to inhibit their growth.

Inhibiting the bacterial cell membrane would be a poor choice because it would be a physical means of antibiotic mechanism against which it is easier for the bacteria to develop antibiotic resistance against.