MDCAT Biology MCQ #450

Before entering the Krebs cycle, pyruvate undergoes oxidation. Which outcome distinguishes this 'link reaction' from the preceding stage of Glycolysis?

MDCAT Biology MCQ #450

  1. Question 1

    Q1. Before entering the Krebs cycle, pyruvate undergoes oxidation. Which outcome distinguishes this 'link reaction' from the preceding stage of Glycolysis?

    • A) The conversion of a six-carbon sugar into three-carbon acids
    • B) The net production of two ATP molecules via phosphorylation
    • C) The occurrence of the reaction in the absence of oxygen
    • D) The removal of a carbon atom to form a CO2 molecule

    Answer: The removal of a carbon atom to form a CO2 molecule

    Explanation: Pyruvate oxidation produces one CO2 and one NADH per pyruvate, whereas Glycolysis produces two NADH and no CO2.