Electron Transport Chain Steps

Step 1:

Electron Donations from NADH and FADH2

NADH and FADH2, produced during glycolysis and the Krebs cycle, donate electrons to the first protein complexes(Complex I for NADH and Complex II for FADH2)

Step 2:

Proton Pumping into intermembrane space

As electrons move through the chain, they release energy. This energy is used by protein complexes (Complexes I, III, and IV) to pump protons (H+) from the mitochondrial matrix into the inter membrane space, creating a proton gradient.

Step 3:

Oxygen - the final electron acceptor!

At the end of the chain oxygen acts as the final electron acceptor, which combines with protons and forms water.

Step 4:

Chemiosmosis via ATP Synthase

The proton gradient drives protons back into the matrix through ATP synthase, a protein complex that uses the energy from this movement to convert ADP and phosphate into ATP.