Consider the cycle between glycolysis and gluconeogenesis. The two pathways operate in opposite directions. Identify which pathway is exergonic and which is endergonic.

• A. Both are endergonic reactions.
• B. Both are exergonic reactions.
• C. Glycolysis is endergonic while gluconeogenesis is exergonic.
• D. Glycolysis is exergonic while gluconeogenesis is endergonic.

Answer: (D)