Which statement about AMPK is true?

• A. It triggers calcium release.
• B. It regulates numerous muscle signaling processes.
• C. It is the primary energy source.
• D. It inhibits protein synthesis.

Answer: (B)

AMPK is an energy-sensing kinase that coordinates metabolic signaling in skeletal muscle. When cellular energy is low, AMPK becomes activated and helps steer the muscle toward pathways that generate ATP while dialing back processes that consume energy. This central coordinating role means it interacts with many different signaling routes in muscle, affecting glucose uptake, fatty acid oxidation, mitochondrial biogenesis, autophagy, and more. That breadth is why the statement it regulates numerous muscle signaling processes is the best description of AMPK’s role.

Calcium release is mediated by calcium channels and receptors, not a primary action of AMPK itself. AMPK is not the fuel source; it’s a sensor and regulator. It can influence protein synthesis indirectly by inhibiting mTORC1 during energy stress, but the defining feature is its wide control over diverse signaling pathways in muscle, which is why that option best captures its function.