Which statement correctly describes exergonic and endergonic reactions and the role of ATP?

• A. Exergonic reactions release energy and are spontaneous; endergonic reactions require energy input. ATP hydrolysis releases energy that is used to drive endergonic cellular reactions, often via coupling to phosphate transfer.
• B. Endergonic reactions release energy and are spontaneous; exergonic reactions require energy input.
• C. Exergonic reactions release free energy and are spontaneous; endergonic reactions require energy input; ATP hydrolysis provides energy for endergonic processes.
• D. ATP hydrolysis stores energy in ATP for later use.

Answer: (C)