Fig. 2
From: Essential roles of mitochondrial and heme function in lung cancer bioenergetics and tumorigenesis
Multiple forms of heme are required for the proper functioning of mitochondrial OXPHOS Complexes. Heme serves as the prosthetic group for many mitochondrial respiratory complexes. This cartoon demonstrates the different types of heme that serve as prosthetic groups for mitochondrial complexes—complex II, complex III, and complex IV. Hence, heme serves a pivotal role in mitochondrial oxidative phosphorylation. Indicated in red is the direction of electron transport through a series of transporters embedded in the mitochondrial inner membrane that shuttles electrons from NADH and FADH2 to molecular oxygen