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What is the function of the electron transport system (ETS)?

A. It metabolizes pyruvic acid to form ATP, NADH, and FADH2. Both NADH and FADH2 are then used to make four molecules of ADP using electron transfer. The stroma of the cell is the site of this cyclical process.

B. It breaks down a six-carbon sugar into two three-carbon pyruvic acid molecules. For each six-carbon sugar, two molecules of ATP and one molecule of NADH are formed. This process takes place in the thylakoid membrane.

C. It takes electron-carrier molecules made during glycolysis and the Krebs cycle and uses them to make ATP. The ETS takes place in the cristae of the mitochondria and provides 34 molecules of ATP for every one glucose molecule that enters glycolysis.

D. It takes six-carbon sugar molecules made during the Krebs cycle and uses them to make ADP. The ETS takes place in the granum of the mitochondria and provides 16 molecules of ADP for every one glucose molecule that enters glycolysis.