A 60-year-old man with uncontrolled diabetes mellitus presents with fatigue, weight loss, and excessive thirst. Blood tests reveal hyperglycemia and ketosis. The physician explains that his body is breaking down fats to produce ketones for energy because glucose is not being utilized efficiently. This metabolic switch relies on biochemical reactions that must be thermodynamically favorable to proceed. Which of the following best describes a reaction that occurs spontaneously in metabolism?
