MDCAT Biology MCQ #248

During chemiosmotic ATP synthesis in chloroplasts, protons are actively pumped into the thylakoid lumen. What is the immediate effect on the stroma?

MDCAT Biology MCQ #248

  1. Question 1

    Q1. During chemiosmotic ATP synthesis in chloroplasts, protons are actively pumped into the thylakoid lumen. What is the immediate effect on the stroma?

    • A) Increase in stromal pH
    • B) Decrease in stromal pH
    • C) Increase in lumen pH
    • D) Neutralization of lumen

    Answer: Increase in stromal pH

    Explanation: Pumping protons into the lumen makes the stroma basic (higher pH). The lumen becomes acidic (lower pH), which is a common distractor.