Question

What percentage of RNAP (RNA polymerase) is present in a storage form (core) and how much is actually in elongation mode?

A. 50%; 50%
B. 40%; 60%
C. 25%; 75%
D. 50%; 25%

Answer 1

The correct option is B. Approximately 40% of RNA polymerase is present in the storage form (core), while the remaining 60% is in the elongation mode.

Step-by-step explanation:

The percentage of RNA polymerase (RNAP) present in the storage form (core) and in elongation mode can be determined by understanding the composition and function of RNA polymerase in prokaryotes. In E. coli, the RNA polymerase is composed of five subunits: α, α, β, β', and σ. The core enzyme is made up of four subunits (α, α, β, β') and accounts for approximately 40% of the total RNA polymerase.

During transcription elongation, the core enzyme proceeds along the DNA template and synthesizes mRNA in the 5' to 3' direction at a rate of approximately 40 nucleotides per second. This elongation mode accounts for the remaining 60% of the total RNA polymerase.