Question

reexamining catalase

background information: hydrogen peroxide (h₂o₂) is a toxic byproduct of cell metabolism. it must be broken down into a non-toxic form in our bodies. this is accomplished by an enzyme called catalase. catalase is found in both plant and animal cells. in plants, such as a potato plant, it is highly concentrated in the “meat” part of the potato. in animals, it is highly concentrated in the cells of the liver.

1. what type of organic macromolecule (nucleic acid, carbohydrate, lipid, protein) is catalase? ______

1. many enzymes either use water from, or release water into, the cellular environment during an enzymatic reaction.

(a) describe how water from the cellular environment might be used to complete an enzymatic reaction.
(b) describe how water might be released into the cellular environment to complete an enzymatic reaction.

Explanation:

Question 1

Enzymes are biological catalysts, and most enzymes are proteins. Catalase is an enzyme, so it is a protein.

In hydrolysis reactions (catalyzed by enzymes), water is used to break down macromolecules. The enzyme facilitates the addition of a water molecule to break a covalent bond in a substrate, e.g., breaking a peptide bond in a protein or a glycosidic bond in a carbohydrate.

In dehydration synthesis (condensation) reactions (catalyzed by enzymes), two molecules are joined. A hydroxyl group from one and a hydrogen from another combine to form and release water, e.g., forming a peptide bond between amino acids or a glycosidic bond between monosaccharides.

Answer:

Protein

Question 2(a)