Question

CAMP activates cAMP-dependent protein kinase by

Answer 1

Answer:

binding regulatory subunits and inducing their release from the  catalytic subunits

Explanation:

cAMP molecules diffuse into the cytoplasm where they bind to an allosteric site on a regulatory subunit of a cAMP-dependent protein kinase ( protein kinase A,  PKA).

-In its inactive form, PKA is a  heterotetramer comprised of two subunits namely, regulatory (R) and two catalytic (C) subunits.

-The regulatory subunits normally inhibit  the catalytic activity of the enzyme. cAMP binding causes the  dissociation of the regulatory subunits, thereby releasing the  active catalytic subunits of PKA.

-cAMP stimulates glucose mobilization by  activating a protein kinase that adds a phosphate group  onto a specific serine residue of the glycogen phosphorylase  polypeptide.