6: ENZYMES

Question 1

1. It is a protein with catalytic properties due to its power of specification.

a. Nucleic Acid

b. Vitamin

c. Enzyme

d. Lipid

Answer 1

c. Enzyme

Question 2

2. Statement 1: Increasing the activation energy can make the reaction of enzymes faster. Statement 2: Increasing the temperature can also make the reaction of enzymes faster.

a. Statement 1 is true, Statement 2 is false

b. Statement 1 is false, Statement 2 is true

c. Both statements are true

d. Both statements are false

Answer 2

b. Statement 1 is false, Statement 2 is true

Question 3

3. A non-protein chemical compound or metallic ion that is required for an enzyme’s activity

as a catalyst.

a. Apoenzyme

b. Holoenzyme

c. Cofactor

d. Coenzyme

Answer 3

c. Cofactor

Question 4

4. Holoenzyme is the complete enzyme consisting of an apoenzyme and a cofactor. Select the option that correctly identifies the nature of the apoenzyme and cofactor.

a. Apoenzyme protein; Cofactor non-protein

b. Apoenzyme non-protein; Cofactor - protein

c. Apoenzyme - protein; Cofactor - protein

d. Apoenzyme - non-protein; Cofactor non-protein

Answer 4

a. Apoenzyme protein; Cofactor non-protein

Question 5

5. Which of the statements regarding enzymes is false?

a. Enzymes are proteins that function as catalysts.

b. Enzymes are specific.

c. Enzymes provide activation energy for reactions.

d. Enzyme activity can be regulated.

Answer 5

c. Enzymes provide activation energy for reactions.

Question 6

6. Without the presence of enzymes, the reactions necessary to sustain life would require in order to occur.

a. Larger Cells

b. Higher Temperatures

c. Larger Proteins

d. Smaller atoms

Answer 6

b. Higher Temperatures

Question 7

7. The part of the enzyme where the substrate binds is called the:

a. Active site

b. Catalyst

c. Inhibitor

d. Large subunit

Answer 7

a. Active site

Question 8

8. Some people cannot digest milk products because they lack a specific enzyme. Which enzyme would be used to break down the lactose in milk?

a. Hydroxylase

b. Maltase

c. Peroxisomes

d. Lactase

Answer 8

d. Lactase

Question 9

9. Enzymes are composed of what organic molecule?

a. Sugars

b. DNA

c. Fatty acids

d. Proteins

Answer 9

d. Proteins

Question 10

10. Which of the following enzyme classes catalyze reactions in which two molecules are covalently connected to each other?

a. Kinase

b. Lyase

c. Isomerase

d. Ligase

Answer 10

d. Ligase

Question 11

11. What is the significance of substrate specificity in enzyme reactions?

a. It allows enzymes to bind to any molecule

b. It ensures that enzymes only react with specific substrates

c. It speeds up all chemical reactions in the cell

d. It prevents the formation of products in a reaction.

Answer 11

b. It ensures that enzymes only react with specific substrates

Question 12

12. The International Union of Biochemistry and Molecular Biology has introduced a concept known as EC numbers. These are categorized into how many groups?

a. 13

b. 5

c. 6

d. 2

Answer 12

c. 6

Question 13

13. Who proposed the ‘Lock and Key Hypothesis’ in 1984?

a. Emil Fischer

b. Albert Einstein

c. Daniel Koshland Jr.

d. Stephen Hawking

Answer 13

a. Emil Fischer

Question 14

14. The following are the factors that affect the activity of enzymes. Which is NOT?

substrate concentration

II. including pH temperature

IV. enzyme concentration

V. substrate molecules

a. I and III

b. Il and IV

c. III only

d. V only

Answer 14

d. V only

Question 15

15. It is the most straightforward and obvious form of enzyme inhibition. It competes with the substrate molecules for the active site.

a. Non-competitive Inhibitors

c. pH range

d. temperature

b. Competitive Inhibitors

Answer 15

b. Competitive Inhibitors