Catalysts and Intermediates

$V_{0} = \frac{V_{max}[S]}{K_{M} + [S]}; K_{M} = \frac{[E][S]}{[ES]}$

AlyssaPeckham1A
Posts: 49
Joined: Fri Sep 29, 2017 7:04 am

Catalysts and Intermediates

could someone further explain the concepts for catalysts and intermediates?

YashDeshmukh1D
Posts: 42
Joined: Fri Sep 29, 2017 7:05 am

Re: Catalysts and Intermediates

Both catalysts and intermediates get cancelled out during the elementary steps of a reaction and do not appear in the overall reaction equation.

Catalysts speed up the reaction by providing an alternate pathway (or reaction mechanism) with a lower activation energy, allowing the reaction to proceed at a faster rate. However, since the rate increases for both forward and reverse reactions, the equilibrium constant (K) stays the same.

Catalysts are usually part of the first step of the reaction and are quickly cancelled out after. This is different from intermediates, which are produced by one of the reaction steps and then consumed by another step.

Justin Lai 1C
Posts: 50
Joined: Fri Sep 29, 2017 7:04 am

Re: Catalysts and Intermediates

The main difference is that catalysts occur in the beginning and the end of the reaction. They may both be cancelled out, but catalysts occur in the beginning and may be consumed in one of the elementary steps, but in the end the catalyst will reform as it was in the beginning. An intermediate will be formed and consumed in the elementary steps meaning that it will not be present in the end of the reaction.

Katie Lam 1B
Posts: 52
Joined: Fri Sep 29, 2017 7:06 am

Re: Catalysts and Intermediates

Catalysts are usually part of the original reactants. They are not formed in one of the reactions, like intermediates are.

Gwyneth Huynh 1J
Posts: 30
Joined: Fri Sep 29, 2017 7:05 am

Re: Catalysts and Intermediates

Also, catalysts show up in the rate law while intermediates do not.

Rachel Wang
Posts: 49
Joined: Fri Sep 29, 2017 7:04 am

Re: Catalysts and Intermediates

Intermediates are not present at the beginning of the rxn and are instead produced during the rxn. They are always consumed by the end of the rxn.
Catalysts are present at the beginning AND the end as they are not consumed by the rxn. They speed up the rxn but are not present in the overall rxn equation.