Enzymes lower the activation energy for certain reactions, but why is that different from changing the energy released or used in the reaction?

Question

Enzymes lower the activation energy for certain reactions, but why is that different from changing the energy released or used in the reaction?

In: Biology

Answer 1

Chemical reactions don’t instantly go from start to finish, there’s a physical process that has to occur where the atoms must rearrange and move past eachother.

Since atoms are shrouded in electrons that repel eachother with considerable force, it can be difficult to actually make that rearrangement happen – there’s a high energy “transition state” that occurs when the molecules have contacted but not yet fully reacted.

A catalyst changes the process and/or geometry of that transition state, lowering the energy needed to reach it and speeding up the reaction.

Now instead of going 10-28-7 and releasing 3 energy, you can go 10-12-7 and release 3 energy.

You still release only three, but you don’t have to gather up eighteen first to initiate the process anymore.