The ATP molecule shown is the universal energy source for cellular activities. Which of these processes is used to break down glucose into ATP that is usable by the cell? A) chemosynthesis B) photosynthesis C) respiration D) transpiration

Let's do this by process of elimination: A cannot be the answer because glucose is broken down, not built up or synthesized. B is ruled out for the same reason. D is incorrect because transpiration results in water loss, not energy gain. The only correct answer choice is C respiration, specifically by the process of substrate-level phosphorylation during glycolysis in order to break down glucose into two pyruvate molecules and two net ATP