MDCAT Biology MCQ #322

Protons are pumped into the thylakoid lumen during light reactions, causing the pH there to:

MDCAT Biology MCQ #322

  1. Question 1

    Q1. Protons are pumped into the thylakoid lumen during light reactions, causing the pH there to:

    • A) Increase significantly
    • B) Stay neutral
    • C) Equalize with the stroma
    • D) Decrease significantly

    Answer: Decrease significantly

    Explanation: Proton accumulation in the lumen lowers the pH. The stroma is tempting because its pH remains higher during light reactions.