question_answer

Which of the following factor is required for the protein synthesis?

(i) Initiation codon

(ii) GTP and ATP

(iii) Peptidyl transferase

(iv) tRNA

(v) mRNA

(vi) Amino acid activating enzyme

(vii) rRNA

Choose the correct combination.

A) (i), (ii) and (iii)

B)                    (iii), (iv) and (v)

C) (v), (vi) and (vii)                        

D) All of these

Correct Answer: D

Solution :

[d] Machinery for Protein Synthesis (i) Ribosome protein synthesis occurs over the ribosome. They are also called protein factories. There are two kinds of ribosomes found in eukaryotes and prokaryotes respectively called prokaryotic ribosome (70S) and eukaryotic ribosome (80S). There are three reactive sites in ribosome P-site (Peptidyl transfer or donor site) A-site (Amino acyl or acceptor site) E-site (Exit site)   (ii) Amino Acid- There are about 20 amino acids and amides which constitutes the building blocks of protein. They occurs in cellular pool. (iii) mRNA- It brings coded information from DNA and takes part in its translation by bringing amino acids in a particular sequence. (iv) tRNA - They pick up particular amino acids in the process called charging. The charged tRNAs take codons corresponding to their anticodons. (v) Aminoacyl tRNA synthetase enzyme helps in combining amino acid to its particular tRNA. The enzyme is specific for each amino acid and also called as amino acid activating enzyme.