Each complex in the electron transport chain collectively acts as a ________ pump that removes H⁺ from the mitochondrial matrix and pumps it into the space between the inner and outer mitochondrial membranes.

A) proton
B) electron
C) neutron
D) sodium-potassium
E) calcium

Proton Pump

An integral membrane protein that builds up a proton gradient across a biological membrane by actively transporting protons.

Electron Transport Chain

An assembly of complex molecules that facilitate the movement of electrons from donating molecules to accepting ones using redox reactions, and this movement is linked with the relocation of protons (H+ ions) through a membrane.

Mitochondrial Matrix

The innermost compartment of the mitochondria, filled with enzymes important for ATP production, mitochondrial DNA, and ribosomes.