Question

what is the series of reactions in which pyruvate is broken down into carbon dioxide called?
light dependent reaction
glycolysis
calvin cycle
krebs cycle
electron transport chain

Explanation:

• Light - dependent reactions occur in photosynthesis and use light energy, not related to pyruvate breakdown.
• Glycolysis breaks down glucose into pyruvate, not pyruvate into CO₂.
• Calvin cycle is part of photosynthesis for carbon fixation, not pyruvate breakdown.
• Krebs cycle (Citric Acid Cycle) takes pyruvate (after conversion to acetyl - CoA) and breaks it down, producing CO₂, ATP, and electron carriers.
• Electron transport chain uses electron carriers from Krebs cycle and glycolysis to produce ATP, not directly break down pyruvate into CO₂.

Answer:

D. Krebs cycle