1. Jack consumes two slices of pizza and drinks two large glasses of soda. Half an hour later, he complains of a stomachache. What is the most likely reason for Jack's upset stomach?
A. Soda and lactose from the cheese combined and slowed enzyme activity.
B. Soda mixed with the pizza sauce and sped up digestive enzyme activity.
C. Soda raised the pH in his stomach and sped up digestive enzyme activity.
D. Soda lowered the pH in his stomach and slowed digestive enzyme activity.

2. Which factor decreases the rate of a chemical reaction?
A. An inhibitor
B. A co-factor
C. Increased substrate
D. Cold temperature

3. Which component decreases the activation energy of a chemical reaction?
A. An inhibitor solution
B. Presence of an enzyme
C. Lower substrate concentration
D. Neutral pH levels

4. A biologist adds a vitamin solution to an enzyme/substrate solution that requires co-factors. What will happen to the substrate?
A. The vitamins will bond to the enzymes and increase their reactivity with the substrates.
B. The vitamins will bond to the enzymes and decrease their reactivity with the substrates.
C. The substrate molecules will bond to the vitamin molecules and inhibit bonding of the enzyme.
D. The substrate molecules will bond to the vitamin molecules and stimulate bonding of the enzyme.

5. Jennifer stews peaches to make peach jelly. She believes the homemade jelly will make a healthy treat full of vitamins and enzymes her body needs. Which of the following disproves her prediction?
A. The peaches don't contain enzymes.
B. The jelly has too much sugar to be healthy.
C. The enzymes in the peaches have denatured.
D. The vitamins in the peaches will inhibit the enzymes.

6. What statement best describes what happens during the catalytic cycle?
A. The enzyme breaks the substrate apart to prepare for the reaction.
B. The enzyme positions the substrate to increase access during a reaction.
C. The substrate uses enzyme energy to start the reaction.
D. The active site releases the substrate and replaces it with an inhibitor.

Explanation : Consuming soda after eating pizza lowered the pH of the stomach which consequently, slowed the digestive enzyme activity in the stomach. The enzymes actively digest the food only in highly acidic environment.

Answer 2) Option A) An inhibitor

Explanation : An inhibitor is a substance usually added to a progressing chemical reaction to decrease the rate of reaction and finally stop the reaction.

Answer 3) Option B) Presence of an enzyme

Explanation : When an enzyme is added to a chemical reaction it is often seen that it lowers the energy of activation and catalyzes the reaction. So, enzyme acts as a catalyst and increases the reaction rate.

Answer 4) Option A) The vitamins will bond to the enzymes and increase their reactivity with the substrates.

Explanation : When the biologists adds a vitamin solution to an enzyme or a substrate solution the bonding will take place between vitamins and enzymes and as a result it will increase the reactivity of the substrates.

Answer 5) Option C) The enzymes in the peaches have denatured.

Explanation : When enzymes are stewed or rather boiled they become denatured and the bonds between them breaks, which makes the enzyme useless. Hence, proteins should be eaten raw without boiling at higher temperatures.

Answer 6) Option A) The enzyme breaks the substrate apart to prepare for the reaction.

Explanation : In a catalytic reaction the enzymes usually break the substrate and create more surface area for the reaction to occur.