alleryStart learning →The oxidation of isocitrate in step three produces a molecule with how many carbon atoms?
AThree carbon atoms
BFour carbon atoms
CFive carbon atoms
DSix carbon atoms
Answer & Solution
Correct answer: C. Five carbon atoms
1. Citrate and its isomer isocitrate both carry six carbons.
2. Step three oxidizes isocitrate and produces a five-carbon molecule.
3. The carbon that leaves does so as carbon dioxide, alongside two electrons that reduce the carrier to NADH.
4. A count of six would mean nothing had been released, which contradicts the carbon dioxide leaving.
_Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 7 "Cellular Respiration", section 7.3 Oxidation of Pyruvate and the Citric Acid Cycle_
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