Two ATP molecules are expended in the energy investment phase of glycolysis. Why is this energy necessary to begin the process of glucose catabolism? A) It isn't; glucose contains 686 kcal/mole in its chemical bonds, so its catabolism is spontaneous. B) It is needed to prime the enzymes of glycolysis. C) Glucose is a stable molecule; thus, some energy must be invested to make the molecule unstable and begin the process of catabolism. D) It is needed to generate the electron carrier NAD⁺.

Question

Quizplus · Accepted Answer

Glucose is indeed a stable molecule, and the initial investment of energy in the form of two ATP molecules helps to destabilize glucose, making it more reactive and thus facilitating its breakdown in subsequent steps of glycolysis. This initial investment is crucial for the catabolic pathway to proceed.

Two ATP Molecules Are Expended in the Energy Investment Phase