Question

What is a regulatory gene?

Answer 1

Hint: It is involved in the expression or regulation of one or more genes. They are present at the start of the regulation site where the process of transcription initiates. They encode proteins or act as the RNA that helps in encoding genes.

Complete answer
Gene regulation includes a range of mechanisms that are used by the cells to increase or decrease the production of specific gene products. The step of the gene expression or regulation that will influence the process of transcription resulting in the formation of RNA or in the process of translation that will form the proteins. This process is done with the help of the regulatory gene. They may also code for the repressor proteins in the case of the prokaryotes.
Regulatory proteins or we can say gene regulatory proteins influence the region of DNA molecules, which during the process of transcription, they were transcribed by RNA polymerase.
-The proteins that are included in the transcriptional factors help in controlling the synthesis of proteins in the cells.
-Transcription factors also increase the transcription of a set of genes. Many of the activators are the DNA binding proteins that generally bind to the enhancers or promoter-proximal elements.
-The position on the DNA where the activator binds refers to as an activator site.
-Activators initiate positive regulation sometimes they are also referred to as inducers whereas Repressors initiate the negative regulation.
-The transcription process either increases in rate or is allowed to continue when the activators or inducers bind to an operon.
-The transcription process is slowed or stops when the repressor binds to an operon.

Note:
Activators initiate the positive regulations and Repressors initiate the negative regulations. The transcription process area increases in rate or decreases in rate, whenever the activators or the inducers bind to an operator. The protein CAP is one of the examples of an activator. The protein CAP binds to the promoter in the presence of cAMP and thus increases the RNA polymerase activity.