Question

multiple choice question
which component of the aerobic respiration pathway acts as a proton pump that removes h⁺ from the mitochondrial matrix and pumps it into the space between the inner and outer mitochondrial membranes?

• glycolysis
• the electron - transport chain
• the citric acid cycle
• the matrix reactions

Explanation:

To solve this, we analyze each option:

• Glycolysis occurs in the cytoplasm, not related to mitochondrial proton pumping.
• The electron - transport chain (ETC) in the inner mitochondrial membrane uses energy from electron transfer to pump \(H^+\) from the matrix to the intermembrane space, acting as a proton pump.
• The citric acid cycle (Krebs cycle) in the matrix produces electron carriers and some \(H^+\) but doesn't pump protons across the membrane.
• "Matrix reactions" is a vague term; the main proton - pumping process in aerobic respiration's mitochondrial part is the ETC.

Answer:

The electron - transport chain