Answer:
Krebs cycle
Step-by-step explanation:
It takes place in the matrix of the mitochondria in a closed loop creating an ATP and GTP molecule, three NADH, and one FADH2. In every part of the cycle, energy is used to pump protons to the intermembrane space between the inner and outer membrane of the mitochondria. This proton motive force created by the Krebs cycle is also used to generate more ATPs molecules by ATP synthase.