The electron transport chain of cell respiration occurs:
a. in the cytoplasm
b. within the matrix
c. across the inner membrane
d. across the outer membrane

The electron transport chain is a series of electron transporters embedded in the inner mitochondrial membrane that shuttles electrons from NADH and FADH2 to molecular oxygen. In the process, protons are pumped from the mitochondrial matrix to the intermembrane space, and oxygen is reduced to form water.