State the function of the following in the regulation of the lac operon expression.
i) cAMP receptor protein binding site
ii) LacI operon
i) The CRP binding site is where the activated CRP binds to to enhance the binding of the RNA polymerase to the promoter region and hence enhances the rate of transcription.
ii) The LacI operon contains genes that code for the active repressor protein of the lac operon and hence inhibits the transcription of the genes in the lac operon if the LacI operon is turned on.