24. What is a chemical reaction? What are the chemicals that are added and made called? 25. What is a catalyst?
26. What type of macromolecule are enzymes?
27. How are enzymes able to speed up reactions?
28. Why are enzymes important in living organisms?

24. A chemical reaction is a process in which some substances change into different substances

25. A substance capable of initiating or speeding up a chemical reaction

26. protein macromolecules

27. by lowering the activation energy needed for the reaction to start.

28. Enzymes allow reactions to occur at the rate necessary for life. In animals, an important function of enzymes is to help digest food.

Explanation:

i have this same assignment :)

the sphincter muscles at the end of the digestive tract is the anus.