Answer: Ethanol and carbon dioxide.
- A Acetyl CoA and water
- B Glucose and oxygen
- C Ethanol and carbon dioxide
- D Lactic acid only
Correct answer: C. Ethanol and carbon dioxide
Explanation: Yeast carries out alcoholic fermentation, converting pyruvate into ethanol and CO<sub>2</sub> in the absence of oxygen, regenerating NAD+ needed to sustain glycolysis.
Aerobic respiration unfolds in three locations: glycolysis in the cytoplasm yields a small amount of ATP directly, the Krebs cycle in the mitochondrial matrix harvests electron carriers (NADH, FADH2), and the electron transport chain in the inner mitochondrial membrane uses those carriers to generate the bulk of the ATP, with O2 needed only at this final stage.
Concept context
Glycolysis, the Krebs cycle, the electron transport chain, fermentation, and the respiratory quotient. The cellular energy-release counterpart to photosynthesis.