## Catalyst

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

Jessica Jones 2B
Posts: 80
Joined: Fri Sep 29, 2017 7:04 am

### Catalyst

How are you able to determine which molecule is the catalyst?

Christine Wastila 1H
Posts: 61
Joined: Fri Sep 29, 2017 7:04 am

### Re: Catalyst

I assume you mean in a chemical equation. In this case, since catalysts are neither reactants nor products, they are written above the arrow. If that's not given, I think it would have to be stated in the problem.

Renee Delamater 2H
Posts: 31
Joined: Wed Nov 16, 2016 3:02 am

### Re: Catalyst

I agree - usually the enzyme or catalyst is used in the rxn to change its rate. It wold go above the equation or be given in the word problem.

Jessica Jones 2B
Posts: 80
Joined: Fri Sep 29, 2017 7:04 am

### Re: Catalyst

Yes I thought that was true as well but for problem 5.71, it asks you to figure out which molecule is the catalyst from the equations? How do I do this?

vicenteruelos3
Posts: 42
Joined: Fri Sep 29, 2017 7:07 am

### Re: Catalyst

Catalysts are not consumed so in the steps of the reaction, the species that is used as a reactant in one step, and comes out as a product in a future step is the catalyst

Nicole Jacobs 1C
Posts: 59
Joined: Thu Jul 13, 2017 3:00 am

### Re: Catalyst

the catalyst is in the reactant side of the first step and in one of the other steps it is on the reactant side, so it is used

Marina Georgies 1C
Posts: 30
Joined: Sat Jul 22, 2017 3:00 am

### Re: Catalyst

Catalysts are enzymes; they are "recycled." So look for the substance that appears as a reactant in the first step of a reaction, and the reappears later as a product.