Final answer:
During the TCA cycle, substrate-level phosphorylation occurs in TCA-7.
Step-by-step explanation:
During the TCA cycle, substrate-level phosphorylation occurs in TCA-7. In this step, 1,3-bisphosphoglycerate donates a high-energy phosphate to ADP, forming one molecule of ATP. This is an example of substrate-level phosphorylation, where a phosphate group is directly transferred from a substrate molecule to ADP to form ATP.