Question

(Calmodulin activation pathway) Activated alpha subunit activates ___.

a) Adenylyl cyclase
b) Phospholipase C
c) Protein kinase A
d) Protein kinase C

Answer 1

The activated alpha subunit of a G-protein in the calmodulin activation pathway activates protein kinase A (PKA), which catalyzes phosphorylation and activation of other proteins.

Step-by-step explanation:

The activated alpha subunit of a G-protein in the calmodulin activation pathway activates protein kinase A (PKA). After activation of adenylyl cyclase, cAMP is synthesized and binds to inactive PKA subunits, causing a conformational change that releases active PKA subunits. These active PKA enzymes catalyze phosphorylation and activation of other proteins, including phosphorylase kinase, leading to cellular responses.