Question

One strand of a DNA molecule has the following sequence: 3-AGTACAAACTATCCACCGTC-5. In order for transcription to occur in that strand, there would have to be a specific recognition sequence, called a(n) __________, to the left of the DNA sequence indicated.

Answer 1

Answer: Promoter

Explanation:

Transcription is the first step in gene expression which consists of copying the DNA sequence of a gene to produce a RNA molecule. There are enzymes called RNA polymerases which perform this process of transcription. These enzymes bind nucleotides (the monomers which are part of the nucleic acids) to create a RNA strand using a DNA strand as a mold.

A promoter is a region of DNA that controls the initiation of transcription of a given portion of DNA to RNA. Therefore they promote the transcription of a gene. The promoter region is composed of a specific sequence of DNA located just where the starting point of the DNA transcription is and contains the information needed to activate or deactivate the gene it regulates. The promoter has a binding site for the RNA polymerase enzyme in charge of mRNA synthesis and when it recognizes this site, transcription begins.