Question

Which RNA polymerase(s) transcribes 5S RNA? (5S RNA is a structural RNA found in ribosomes.)

A) III
B) I and III
C) I
D) I and II
E) II

Answer 1

RNA polymerase III is responsible for transcribing the 5S RNA, a structural component of ribosomes. This enzyme also synthesizes tRNAs and snRNAs, crucial for various cellular processes including protein synthesis.

Step-by-step explanation:

The RNA polymerase that transcribes 5S RNA, a structural RNA found in ribosomes, is RNA polymerase III. This enzyme is specifically responsible for synthesizing various types of structural RNAs, including the 5S rRNA, transfer RNAs (tRNAs), and small nuclear RNAs (snRNAs).

While RNA polymerase I is involved in transcribing other rRNA components like 18S, 5.8S, and 28S, and RNA polymerase II synthesizes mRNAs, it is RNA polymerase III that is tasked with producing 5S rRNA, which is a crucial part of the ribosomal machinery needed for protein synthesis.