An inhibitor does what to a chemical reaction? Stops the reaction
Slows it down
Speeds it up
Nothing

 B) Slows it down

The word "inhibit" means "slow down" or "get in the way". Think of a speedbump that slows down a car.

In contrast, a catalyst increases the chemical reaction rate.

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products

your spelling is a little off : ]