I'm writing a sentence about energy coupling:
Energy coupling is a phenomenon where cells use the energy released from an exergonic reaction to fuel a different, endergonic reaction.
I can see "endergonic reaction" being regarded as a noun by itself rather than an adjective and a noun, and therefore the sentence wouldn't need a comma. I can also see "endergonic" being an adjective and "reaction" being a noun, so a comma would be needed before "endergonic".
Do I need a comma after "different"?