Unit 2 Practice Test- Enzymes and Chemical Reactions

1.

Multiple Choice

45 sec

1 pt

An enzyme speeds up a reaction by

lowering the activation energy.

raising the activation energy.

releasing energy.

absorbing energy.

2.

Multiple Choice

45 sec

1 pt

In a chemical reaction, a reactant binds to an enzyme at a region known as the

catalyst.

product.

substrate.

active site.

3.

Multiple Choice

30 sec

1 pt

What are the substances that are created by a chemical reaction?

Products

Reactants

Molecules

Ingredients

4.

Multiple Choice

30 sec

1 pt

The energy needed to start a reaction is called the

activation energy

starting energy

promoting energy

reacting energy

5.

Multiple Choice

45 sec

1 pt

Once an enzyme has helped a reaction take place, it can then

be reused for another reaction with the same reactants.

be broken down.

be stored in the cell until it is needed again.

be used to help different reactants go through a reaction.

6.

Multiple Choice

30 sec

1 pt

What type of macromolecules does an enzyme belong?

Protein

Carbohydrate

Lipid

Nucleic Acid

7.

Multiple Choice

30 sec

1 pt

An enzyme fits its substrate like

a lock and key

peas and carrots

a product and reactant

8.

Multiple Choice

1 min

1 pt

What is the purpose of an enzyme?

give permission for the reaction

raise activation energy

speed up reactions

control how many reactions occur

9.

Multiple Choice

1 min

1 pt

After the enzyme and substrate bind together and perform the reaction, what does the substrate become?

a substrate

an enzyme

a product

an active site

10.

Multiple Choice

1 min

1 pt

In the diagram, what is letter A?

product

substrate

enzyme-substrate complex

active site

11.

Multiple Choice

2 mins

1 pt

The graph shows how enzymes affect reactions in cells. Which statement best summarizes the information shown in the graph?

Enzymes increase the energy of the reactants.

Enzymes decrease the energy level of the products.

Enzyme decrease the activation energy of the reaction.

Enzymes reverse the direction of the reaction.

12.

Multiple Choice

1 min

1 pt

Based on the graph, what is the optimal temperature for this enzyme?

15^oC

40^oC

30^oC

35^oC

13.

Multiple Choice

30 sec

1 pt

Which letter represents the enzyme-substrate complex?

A

B

C

D

14.

Multiple Choice

30 sec

1 pt

Which letter represents the Product ?

B

C

D

E

15.

Multiple Choice

30 sec

1 pt

Which of the following factors affect the action of enzymes to a substrate?

pH and temperature

color and light

salinity and temperature

acidity and oxygen level

16.

Multiple Choice

30 sec

1 pt

What is the optimal pH for this enzyme?

6

10

9

7

17.

Multiple Choice

30 sec

1 pt

Which color line represent a reaction with an enzyme present?

Blue

Red

Both

Neither

18.

Multiple Choice

30 sec

1 pt

The graph below shows how the activity of an enzyme changes over a range of pH values. Which of the following conclusions can be drawn from this graph?

The optimum pH of the enzyme is 6.6.

The optimum pH of the enzyme is 5.8

The enzyme’s activity continually increases as pH increases from 5.0 to 9.0

The enzyme’s activity is greater around pH of 8.0 than around pH of 5.0.

19.

Multiple Choice

2 mins

1 pt

The graph shows how enzymes affect reactions in cells. Which statement best summarizes the information shown in the graph?

Enzymes increase the energy of the reactants.

Enzymes decrease the energy level of the products.

Enzyme decrease the activation energy of the reaction.

Enzymes reverse the direction of the reaction.

20.

Multiple Choice

2 mins

1 pt

Which line represents an enzyme-catalyzed reaction?

Line 1

Line 2

21.

Multiple Choice

1 min

1 pt

The graph shows the effect of temperature on enzyme action. What characteristic do enzymes E₁, E₂, and E₃ share?

Their activity increases between 20°C and 30°C.

Their activity is greatest between 5°C and 10°C.

Their activity is at a low level between 15°C and 25°C.

Their activity is at a high level between 30°C and 40°C.

22.

Multiple Choice

30 sec

1 pt

The portion labeled "D" represents the

reaction with enzyme

reaction without enzyme

reactants

products

23.

Multiple Choice

30 sec

1 pt

The portion labeled "B" represents the

reaction with enzyme

reaction without enzyme

reactants

products

24.

Multiple Choice

30 sec

1 pt

What is the optimal pH of enzyme A?

8

2

5.7-10

10

25.

Multiple Choice

30 sec

1 pt

What is the pH range of enzyme A?

2

0-3.7

3.7

0

26.

Multiple Choice

30 sec

1 pt

Which enzyme is most efficient in a basic solution?

A

B

27.

Multiple Choice

30 sec

1 pt

What type of reaction is this?

Exothermic

Endothermic

Exorcism

Endoscopy

28.

Multiple Choice

30 sec

1 pt

What type of reaction is this?

Exothermic

Endocrine System

Exon Mobil

Endothermic

29.

Multiple Choice

30 sec

1 pt

If the activation energy is lowered, the reaction will....

Speed up

Slow down

Nothing will happen

Both A and B

30.

Multiple Choice

1 min

1 pt

What happens when enzymes are heated to a high temperature?

The enzymes die.

The shapes of the enzyme are altered denature

The enzymes' amino acid sequence changes.

The enzymes remain the same

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