In a biological reaction involving an enzyme, what does not directly participate in the reaction?

the active site of an enzyme

the active site of the substrate

the inactive site of the substrate

the reactant chemicals

What some science videos to you

Mitochondria produce atp, a high energy compound. atp is used for all sorts of enzyme-mediated reactions, such as making proteins/nucleotides/etc, certain compounds cross the cell membrane, muscles move, etc.  without this source of energy, a cell will die. it will not be able to repair itself, defend against pathogens, etc.

Your answer is going to be a. i know my biology