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Multiple Choice
When we consume food, which process in cellular respiration is primarily responsible for converting the chemical energy in glucose into ATP?
A
Glycolysis
B
Citric acid cycle (Krebs cycle)
C
Photosynthesis
D
Electron transport chain
Verified step by step guidance
1
Understand the context: Cellular respiration is the process by which cells convert the chemical energy stored in glucose into ATP, the energy currency of the cell. This process involves multiple stages: glycolysis, the citric acid cycle (Krebs cycle), and the electron transport chain.
Clarify the role of glycolysis: Glycolysis is the first step in cellular respiration, where glucose is broken down into pyruvate. This process generates a small amount of ATP and NADH but is not the primary source of ATP production.
Clarify the role of the citric acid cycle: The citric acid cycle occurs in the mitochondria and processes pyruvate into carbon dioxide while generating NADH and FADH2. These molecules are crucial for the next stage but do not directly produce large amounts of ATP.
Explain why photosynthesis is not relevant: Photosynthesis is a process used by plants, algae, and some bacteria to convert light energy into chemical energy stored in glucose. It is not part of cellular respiration and does not produce ATP in animal cells.
Describe the electron transport chain: The electron transport chain is the final stage of cellular respiration, located in the inner mitochondrial membrane. NADH and FADH2 donate electrons to the chain, creating a proton gradient that drives ATP synthesis via oxidative phosphorylation. This is the primary process responsible for converting the chemical energy in glucose into ATP.