Which enzyme is a key target of the hormone adiponectin and plays a central role in regulating the metabolism of lipids and carbohydrates by phosphorylating other key metabolic enzymes?

Correct answer: AMP-activated protein kinase (AMPK)

Explanation

Adiponectin exerts its powerful effects on metabolism primarily by activating AMP-activated protein kinase (AMPK). Activated AMPK then phosphorylates and regulates multiple downstream enzymes, shifting cellular metabolism towards energy-producing pathways (like fatty acid oxidation) and away from energy-consuming pathways (like fatty acid synthesis).