Final answer:
The two NADHs generated during glycolysis indirectly contribute to ATP production in mitochondria through the electron transport chain. Each NADH can yield approximately three ATP, whereas each FADH2 molecule yields about two ATP. Overall, about 36 ATP are produced from one molecule of glucose during aerobic respiration.
Step-by-step explanation:
In the process of glycolysis, 2 NADH is generated in the cytoplasm of most cells. These NADH molecules shuttle electrons to the mitochondria, but they do not directly transfer their electrons to FADH2. Instead, through the electron transport chain (ETC), the electrons from NADH travel through several complexes that aid in the production of ATP. For every NADH molecule that donates electrons to the ETC, approximately three ATP are produced. However, the two NADH molecules generated during glycolysis need to be transported into the mitochondria using a shuttle system, which consumes ATP and can alter the net ATP gain.
Nevertheless, considering the overall catabolism of glucose, two FADH2 molecules are generated in the mitochondria during the citric acid cycle, and each FADH2 molecule yields about two ATP when oxidized in the ETC. This is because electrons from FADH2 enter at a lower energy level in the ETC (Complex II) than those from NADH (Complex I), resulting in fewer ATPs generated per FADH2.
Therefore, considering the entire cellular respiration process and accounting for the NADH shuttle mechanisms, the net ATP yield might differ. Typically, each glucose molecule eventually results in the formation of approximately 36 ATP during aerobic respiration.