Biochemical function within any cell is determined largely by specific enzymes. remember, enzymes are proteins. different sets of genes must be turned on and off in the various cell types. this is how cells

This is how cells gene regulation occur.

Explanation:

Regulation of gene expression is  very very important thing to maintain the normal levels of all body proteins according to our body"s requirement.

            During positive gene regulation enzymes of various metabolic pathways of the target cell is being activated,thus supplying the cellular need of various metabolites and proteins.

             During negative regulation various enzymes are  turned off thus blocking the formation of metabolites or proteins not required by the cell.