Health Tooty Fruity

Iron is important to energy production in the cell in several different ways. Ironcontaining heme is an essential component of cytochromes. Cytochromes are important for aerobic energy production as part of the electron transport chain. They serve as electron carriers during the synthesis of ATP (adenosine triphosphate), the primary energy storage compound in cells. In the electron transport chain, hydrogen (H) and oxygen (O2) are combined into water (H2O) plus electrons. The ironcontaining cytochromes pass the electrons along the transport chain.

An iron-sulfur protein is also used in the electron transport chain, which pumps up ATP. The final step in the electron transport chain uses a complex containing two copper atoms and two compounds of heme. An enzyme that contains iron and transports electrons is succinate dehydrogenase. This enzyme contains heme and is very important in energy metabolism. Succinate dehydrogenase also contains riboflavin (vitamin B2). This enzyme functions at the crossroads between the tricarboxylic acid (TCA) cycle and the electron transport chain.


There are iron-containing enzymes that do not contain heme that are important to energy metabolism. For example, iron and niacin work together in the enzyme NADH (nicotinamide adenine dinucleotide hydrogenase) to transport electrons in the electron transport chain. You may recall that nicotinamide is a form of niacin, vitamin B3.