Question

Protein synthesis is the main function of which of the following structures? (A) Nucleus (B) Ribosome (C) Chromosome (D) Mitochondrion (E) Vacuole

Answer 1

Answer:

B. Ribosome

Explanation:

Ribosomes are the organelles that serve as a site for protein synthesis. Each ribosome has two subunits. The small subunit first joins with mRNA and the initiator tRNA to start the process of protein synthesis. The large subunit joins the complex and the proteins are synthesized according to the nucleotide sequence of the mRNA read in the form of genetic triplets. Ribosomes are present in cytosol as well as on the surface of the rough endoplasmic reticulum of a eukaryotic cell. In both locations, they are involved in the process of protein synthesis.

Answer 2

Answer:

(B) Ribosome

Explanation:

The ribosome is an organelle composed of RNA proteins and the ribosomal RNA. The proteins and rRNA form the two subunits: the small and large subunit. The ribosomes either attached to the endoplasmic reticulum or float freely in the cytoplasm of the cell.

The structure of RNA contains three sites called A, P and E sites which helps in the "synthesis of proteins" from the mRNA molecule. The mRNA produced in the nucleus gets transported from the nucleus to the ribosomes attached to the endoplasmic reticulum and the proteins are synthesized by the process of translation.

Thus, Option-B is the correct answer.