Question

With the help of a schematic diagram, explain the location and the role of the following in a transcription unit:
Promoter, Structural gene, Terminator.

Answer 1

The answer is stated below:

Explanation:

• A typical transcription unit is comprised of:

1. Promoter: It is a specific sequence in the DNA which is recognised by the RNA polymerase as the transcription start site. It is the location where the process of transcription begins. It is often rich in the nucleotides Thymine(T) and Adenine(A) which form the TATA box.
2. Structural Gene: This region is comprised of the  DNA sequence that encodes for a particular protein. The part of the mRNA or messenger RNA transcribed from this region is recognised by the ribosome to be translated into the corresponding amino acid sequence.
3. Terminator : This is the region where the RNA polymerase stops transcription. This region is usually rich is Adenine (A) nucleotides.