Enzymes – Online MCQs Test – Biology MCAT

1. The inorganic ions which act as a prosthetic group in holoenzymes are called:

Ho a-group

Co-factors

Co-activators

Co-enzymes

2. Enzyme having different molecular arrangement but similar functions is

Iso-enzyme

Co-enzyme

HoIo-enzyme

Apo-enzyme

3. Class hdyrolases includes:

Hydroxylase

Oxidase

Epimerase

Phosphatase

4. Magnesium (Mg⁺²) is an inorganic activators for the enzyme:

Esterase

Carbonic Anhydrase

Amylase

Phosphatase

5. Regarding nature of enzymes, which one is correct?

They are specific both in their nature and action.

They are inorganic catalyst.

They are non-specific in their nature but specific in their action.

Large quantities are required to bring a change in large amount of substrate.

6. Enzymes are useful to plants because.

They are essential for the metabolic processes

They are used up in reactions.

They enhance absorption of water and salts.

They are building blocks of chlorophyll.

7. The pesticides DDT and parathion are inhibitors of key enzymes in the

Nervous System

Respiratory system

Digestive System

Cardivascular System

8. Enzyme hydroxylase is included in class:

Transferases

Hydrolases

Lyases

Oxidoreductases

9. Regarding enzyme molecules:

Smaller in size than the substrate

No relation with substrate

Greater in size than the substrate

Of same size as substrate

10. Decarboxylases and Dehydratases, are enzymes included in class:

Hydrolases

Transferase

Lyases

Ligases

11. Which of the following is not an attribute of enzymes?

They are used up in reactions.

They speed up the rate of biochemical reactions.

They are specific in nature.

They are proteinaceous in nature.

12. Zinc (Zn⁺²) is an inorganic activator for the enzyme:

Esterase

Phosphatas

Amylase

Carbonic Anhydrase

13. The organic prosthetic groups in holoenzymes are called:

Co-enzymes

Co-factors

Holo-group

Co-activators

14. temperature of enzymes present in human body is __________Optimal

33°C

47°C

37°C

27°C

15. Non-competitive inhibitor is one which:

Competes to the active site of enzyme

Binds away from the active site of an enzyme

Binds close the active site of an enzyme

Normally binds to active site of an enzyme

16. Regarding nature of enzymes, which one of the following is correct?

Simple enzyme consists of protein and non-protein part.

Conjugated enzyme consists of non-protein part.

Enzymes are modified lipids.

Amylase is an enzyme which entirely consists of protein.

17. All of the following are correct about enzymes EXCEPT

The mechanism by which enzymes work is known as lock and key

They denature at high temperatures

They are proteins

They are assisted by vitamins and minerals

18. If enzyme concentration is low than substrate, pH and temperature values are equal to requirement then which of the following will increase rate of reaction.

Increase in temperature

Increase in concentration of substrate

Increase in pH

Increase in concentration of enzyme

19. Blocking of active site of an enzyme temporarily is a kind of:

Feedback inhibition

Competitive inhibition

Non reversible

Non-competitive inhibition

20. The prosthetic group (metallic cofactor) of various respiratory enzymes is

Enzymes-Medical College Admission Test Preparation Notes