[Campbell Biology P.235] When electrons flow along the electron transport chains of mitochon... | Practice Question

When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs in the mitochondrial matrix?

  • A: The pH of the matrix increases.
  • B: ATP synthase pumps protons by active transport.
  • C: The electrons gain free energy.
  • D: NAD+ is oxidized.

Explanation

As electrons flow along the electron transport chain, protein complexes pump protons H+ from the mitochondrial matrix into the intermembrane space. This removal of protons from the matrix reduces the proton concentration there, leading to an increase in pH making it more alkaline .