Assume that there is a mutation in the lac I gene List two p

Assume that there is a mutation in the lac I gene. List two possible affects a mutation in this gene could have on the activity of the beta galactosidease enzyme within the cell, and explain HOW the effect would be achieved. Thinking at the level of the codon, what types of mutations would have the greatest effect on enzymatic activity, and which would have the least?

Solution

Lac I encodes for Lac Repressor means it is normally bound to operator but when combined with allolactose it cannot bind to repressor and start gene expression .....

Now in your case if lac I is mutated it will form a non functional repressor which cannot bind to operator .... so it will never stop gene expression and lac operon will always be on B-GAL will always be expressed ... irrespective of wheather lactose is in the environment or not.....

regarding mutations

Frame shift mutations insertions or deletions will have greatest affect on enzymatic activity .... where as simple SNPs ( single nucleotide polymorphisms) which do not result in change of amino acid and conserve amino acid sequece will have least effect on activity

Hope it answers .... Regards .... Feel free to discuss I will be glad to help