What does an inhibitor do ?

Enzyme inhibitors are molecules or compounds that bind to enzymes and result in a decrease in their activity. An inhibitor can bind to an enzyme and stop a substrate from entering the enzyme's active site and/or prevent the enzyme from catalyzing a chemical reaction. There are two categories of inhibitors.

Explanation:

I had to look this up lol. hope it helps tho!

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.