What is the defining characteristic of a catalyst?
AIt is consumed during the reaction
BIt speeds up a reaction without being used up
CIt increases the amount of product formed
DIt changes the products of a reaction
A catalyst speeds up a reaction without being permanently changed or consumed. It participates in the reaction process but is regenerated at the end, so it can catalyze the same reaction many times. It does not change what products form or how much product is made.
Question 2 True / False
A catalyst increases the total amount of product that a reaction can produce.
TTrue
FFalse
Answer: False
A catalyst speeds up the rate at which products form but does not change the total amount of product. The same amount of product would eventually form without the catalyst — it would just take much longer. Catalysts affect speed, not quantity.
Question 3 Short Answer
What is the name for catalysts that speed up chemical reactions in living organisms?
Think about your answer, then reveal below.
Model answer: Enzymes.
Enzymes are biological catalysts — specialized protein molecules that speed up the thousands of chemical reactions happening in your cells every second. Without enzymes, reactions like digesting food or building DNA would be far too slow to sustain life. Each enzyme typically catalyzes one specific reaction.