Question
Biology Question on the molecular basis of inheritance
'Lac operon' in E. coli, is induced by
A
I' gene
B
promoter gene
C
P-galactosidase
D
lactose.
Answer
lactose.
Explanation
Solution
Lac operon of E.coli is responsible for the uptake and initial catabolism of lactose. The lac operon consists of three structural genes (lac Z, lac1 Y, lac A). lac Z codes for P- galactosidase which hydrolyses lactose to glucose and galactose. lacY codes for lac permease, a membrane-bound protein constituent of the lactose transport system, lac A codes of thioglactoside transacetylase, an enzyme of uncertain metabolic function.