Question

Ribososomes are CORRECTLY characterized by which of the following statements?

• A. They are composed entirely of r-RNA
• B. They are composed of two equal subunits.
• C. They differ in response to antibiotics depending on whether they are eukaryotic or prokaryotic in origin.
• D. They are composed of three equal subunits.

Answer 1

Answer: (C)

Ribosomes are membrane less organelles found in both types of cells- eukaryote and prokaryote. Ribosomes are made of mix of proteins and ribosomal RNA. This organelle is important for the process of protein synthesis. It helps in translating mRNA and joining the amino acids together forming long polypeptide chain. Each ribosome is made up of two subnits - one large subunit and other small subunits.
The ribosomes of the eukaryotes are of 80S type and that of prokaryotes are of 70S.
Antibiotics are chemicals that kill or inhibit growths of bacterial cells. Certain antibiotics work by targeting the ribosomes where it inhibits the ribosomal functions either by blocking peptide formation or interfering with the translation process. Antibiotics chemical bind to the ribosomal subunits and inhibit the process. The bacterial antibiotics are specific to the prokaryotic ribosome and do not bind to the eukaryotic ribosome.