It is important in the production of ATP through its role as an enzyme cofactor.
Iron is necessary for photosynthesis and is present as an enzyme cofactor in plants.
Add to this the evolution of the posttranslational pathway with four enzyme cofactors and you have a protein that is complicated and expensive to manufacture.
The first evidence for the requirement of flavin as an enzyme cofactor came in 1935.
Some 4Fe-4S clusters bind substrates and are thus classified as enzyme cofactors.
Modern methanogens require nickel as an enzyme cofactor.
Similarly, copper functions as an enzyme cofactor in bone formation.
AB variant is caused by a failure in the gene that makes an enzyme cofactor for beta-hexosaminidase, called the GM2 activator.
Vitamin B acts as an enzyme cofactor in a variety of metabolic processes.
Most of the vitamins are enzyme cofactors, and some doctors believe that a lack of vitamins can make people more sensitive to environmental chemicals (pp 259-60).