Are cofactors consumed in the reaction?

sameeralord

Hello everyone,

I have a quick clarification. Enzymes are not consumed in the reaction but cofactor like NAD+ is consumed in reaction right. So does NAD+ first bind to the enzyme and then get reduced in certain reactions? Thanks

alxm

"Cofactor" really means anything that's not an amino acid which is bound to the enzyme and required for it to function. A cofactor like NAD+/NADH usually participates as an electron acceptor/donor in the reaction, so it's part of the reaction.
On the other hand a metal ion might just sit in the protein and coordinate to a couple of negatively charged ligands and have a purely structural role, with no participation at all. And the cytochrome cofactors in Cytochrome C Oxidase participate in the reaction, but act as catalysts and aren't consumed.

So 'cofactor' doesn't imply anything about whether or not it plays a role in the reactivity.

sameeralord

Ok thanks