Looking for classes? Ksquare Career Institute, Bengaluru →
In negative operon : -
A
Inducer binds with repressor
B
Co-repressor does not bind with repressor
C
Co-repressor binds with inducer
D
cAMP has negative effect on lac operon
Detailed Solution
In negative control (e.g. the lac operon), a repressor protein binds to the operator and switches the genes off.
In an inducible operon, the inducer (e.g. lactose or allolactose) binds to the repressor, changes its shape and makes it unable to bind to the operator. So the genes are switched on.
In a repressible operon (e.g. trp operon), the co-repressor (tryptophan) binds to the repressor (not to the inducer) and activates it.
cAMP, with CAP, has a positive effect on the lac operon.
So in a negative operon, the inducer binds with the repressor.
In an inducible operon, the inducer (e.g. lactose or allolactose) binds to the repressor, changes its shape and makes it unable to bind to the operator. So the genes are switched on.
In a repressible operon (e.g. trp operon), the co-repressor (tryptophan) binds to the repressor (not to the inducer) and activates it.
cAMP, with CAP, has a positive effect on the lac operon.
So in a negative operon, the inducer binds with the repressor.