MDCAT Biology MCQ #430

According to the chemiosmotic hypothesis, ATP synthesis in mitochondria occurs when protons move through ATP synthase from the:

MDCAT Biology MCQ #430

  1. Question 1

    Q1. According to the chemiosmotic hypothesis, ATP synthesis in mitochondria occurs when protons move through ATP synthase from the:

    • A) Matrix to intermembrane space
    • B) Intermembrane space to matrix
    • C) Stroma to thylakoid lumen
    • D) Thylakoid lumen to stroma

    Answer: Intermembrane space to matrix

    Explanation: Protons flow from the intermembrane space back into the matrix. The thylakoid lumen is tempting but applies to chloroplasts, not mitochondria.