Hey, maybe I’m falling too deep into thinking about this, but I’m very confused about the delineation between coenzymes and cofactors, and how prosthetic groups, minerals, and vitamins add to the confusion.
Cofactors are inorganic, usually mineral-derived but can be mineral derive, that act as helper molecules, usually metal cations, that participate in catalysis, such as DNA polymerase using Mg²⁺ to stabilize the negative charge of the phosphates on DNA.
Coenzymes are organic nonprotein molecules, ONLY vitamin-derived d, that assist enzymes by carrying electrons, atoms, or functional groups between reactions.
My confusion is how I’m supposed to delineate something like FAD, which is vitamin-derived. It functions as a coenzyme that carries electrons, but also as a cofactor because it directly participates in catalysis, and also as a prosthetic group because it is covalently bound to Complex II. I’m assuming that the MCAT wouldn’t give me all three options and that I should broadly know that coenzymes are organic and cofactors are inorganic, and that the hierarchy of classification from broadest to most specific goes:
cofactors → coenzymes → prosthetic groups.