Without regulation, all gene products would be synthesized all the time.
Regulation is important for efficiency, only make a product when it is needed.
Regulation is also important in cell differentiation in multicellular organisms, because all cells contain the same DNA template, but the information is utilized differently in different cell types. Gene Structure, multiple regions within a gene sequence are important in regulation. Translational regulation , Sequences in the RNA control the recognition by the translation initiation complex, efficiency of translation initiation, stability of the RNA molecule. Example, binding of a regulatory protein to operator recruits RNA polymerase to the promoter and stimulates transcription. Example, binding of a regulatory protein to operator region blocks RNA polymerase from the promoter and inhibits transcription.