1

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Lactase and carbonic anhydrase are examples of what type of substance?

A

substrate

B

reactant

C

product

D

enzyme

2

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Which statement correctly describes a chemical reaction?

A

Reactants come out of a reaction.

B

Energy is always released.

C

Bonds between atoms break and reform.

D

Products go into a reaction.

3

Which is the best definition of activation energy?

A

the energy required to end a chemical reaction

B

the energy required to bind a substrate to an active site

C

the energy required to form or break the bonds of reactant molecules

D

the energy required to re-form bonds in product molecules

4

Which two substances bind using a lock-and-key mechanism?

A

enzyme and substrate

B

reactant and substrate

C

substrate and product

D

reactant and product

5

Photosynthesis is an example of

A

an exothermic reaction.

B

an endothermic reaction.

C

a reaction that gives off heat.

D

a reaction that emits energy.

6

What is a substrate?

A

a molecule that acts as a catalyst

B

a place on the enzyme where the reaction occurs

C

a place on the product where the enzyme fits

D

a reactant that is catalyzed by an enzyme

7

A researcher is designing a laboratory experiment to determine whether the inorganic substance A affects the rate of a reaction between two colored liquids, X and Y. When the reaction is complete, the liquid is clear. The reaction between X and Y is similar to one used by manufacturers to produce certain chemicals in factories.Which method would best answer his question about reaction rate and what will he find out about substance A?

A

First, he should measure the final temperature of the liquid when X and Y react without substance A. Then, he should measure the final temperature when he adds substance A to X and Y. He will find out if substance A is a catalyst.

B

First, he should measure how long it takes for the liquid to become clear if X and Y are mixed together. Then, he should measure how long it takes if he also adds substance A to X and Y. He will find out if substance A is a catalyst.

C

First, he should measure the final temperature of the liquid when X and Y react without substance A. Then, he should measure the final temperature when he adds substance A to X and Y. He will find out if substance A is an enzyme.

D

First, he should measure how long it takes for the liquid to become clear if X and Y are mixed together. Then, he should measure how long it takes if he also adds substance A to X and Y. He will find out if substance A is an enzyme.

8

The lock-and-key mechanism refers to

A

the complementary shapes of an enzyme and a substrate.

B

the attractive forces between an enzyme and a substrate.

C

the ability of an enzyme to lower the activation energy of a reaction.

D

the ability of an enzyme to “unlock” the products of a reaction.

9

A substance that influences the reaction but does not participate in the reaction is a

A

catalyst

B

reactant

C

product

D

substrate

10

How does a catalyst work?

A

by increasing the temperature of a chemical reaction

B

by decreasing the pressure of a chemical reaction

C

by increasing the concentration of reactants in a reaction

D

by decreasing the activation energy of a reaction

Catalysts Answers

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