Name the components of lac operon and discuss their role

Explanation

The lac operon encodes for the genes needed to utilize lactose as an energy source. The lac operon contains an operator, promoter, and structural genes. These genes are transcribed together and are under the control of the catabolite activator protein (CAP) or repressor. When the level of glucose is low or nonexistent, but lactose is absent, the lac operon is not activated and transcription remains off.
(i) Promoter is the site where RNA polymerase attaches in order to transcribe mRNA.
(ii) Regulator gene or I gene is transcribed to make mRNA which is translated to a repressor protein. There is a termination signal at the end of the I gene.
(iii) Gene codes for Operator, it is a short sequence of bases that acts like a switch that can be recognized by repressor protein.
(iv) Z, Y and A are all .structural genes (genes that code for polypeptides) Z codes for Bgalactosidase, Y codes for lactose permease, a protein that functions to actively bring lactose from outside to cell to the inside, even against a concentration gradient. A codes for trans-acetylase, an wenzyme that is also needed to breakdown many sugars related to lactose.