Don’t enzymes always stabilize the transition state?

[u/DrMrSirJr]

Specifically referring to the bullet that says:"Enzymes act by stabilizing the transition state, providing a favorable microenvironment, or binding with the substrate molecules"

Kaplan is phrasing it as if it can either do that or do one of those other options given. It’s also written this way in the main part of the text for this chapter too. But I thought it always stabilizes and lowers the energy of the transition state? Thought that’s like by definition how they work.

[u/Different_Smell_9483]

You are right. Enzymes stabilze the transition state and lower Ea. This is the overarching idea.
They are just also describing catalytic strategies in the above part, and how enzymes work in the bottom part. But what do enzymes do exactly? Stabilize transition state and lower Ea. Hope this helps clarify it for you!

[u/DrMrSirJr → u/Different_Smell_9483]

The specific bullet I was confused by was when it said: "Enzymes act by stabilizing the transition state, providing a favorable microenvironment, or binding with the substrate molecules"

That sounds like stabilizing the transition state is only one of three functions of an enzyme and not necessarily something enzymes always do?

Wouldn’t it be more accurate to say it stabilizes the transition state, and that those other two are a couple mechanisms by which is achieves that?

[u/Different_Smell_9483 → u/DrMrSirJr]

creating a favorable microenvironment or binding substrates, are ways the enzyme can achieve that stabilization. Does this help more?

[u/DrMrSirJr → u/Different_Smell_9483]

Yes it does! That’s what my suspicion was, thank you. The wording just made it sound like it was one of three options rather than the goal of those two means.

Thanks

[u/Frannyj]

They do all of the described mechanisms. Have you taken biochem yet? The microenvironment thing is apparent if you study molecular metabolism. Specific residues will for example donate a proton. Some will provide a metal ligand to stabilize transition states. They do a lot of different things and it shouldn’t be too confusing if you have your requisite content. Watch some khan academy videos if it is still confusing or don’t know where to start. But this is why I hound people to take biochem before the mcat. You’re reading an abridged version of a 900 page textbook 

[u/DrMrSirJr → u/Frannyj]

I took biochem but I’m nontrad. I graduated 7 years ago.

I just meant the one line where it goes:
"Enzymes act by stabilizing the transition state, providing a favorable microenvironment, or binding with the substrate molecules"

Cuz this makes it sound like stabilizing the transition state is only one of three functions of an enzyme and not necessarily something enzymes always do?

Wouldn’t it be more accurate to say it stabilizes the transition state, and that those other two are a couple mechanisms by which is achieves that?

[u/love4painting]

My understanding is if a specific enzyme doesn’t interact with a certain molecule, then it doesn’t affect the transition state of that molecule’s reaction

[u/DrMrSirJr → u/love4painting]

Sorry could you expand?

[u/HamouzArctic]

For the sake of the MCAT yes.