In this diagram the inner mitochondrial membrane is indicated in the yellow. The enzymes of the electron transport chain are located in clusters that are embeded in the inner mitochondrial membrane.
NADH-CoQ reductase complex
CoQH-cytc reductase complex
Succinate-CoQ reductase complex
CytC oxidase complex.
The pathway of electron flow is indicated by the arrows.
The relationship between the enzyme clusters and the individual reactions is shown in the diagram below.