Enzymes – Online MCQs Test – Biology MCAT

1. In case of conjugated enzymes the non-protein part is called:

Prosthetic group

Protosthetic group

Apoenzyme

Holoenzymes

2. In case of conjugated enzymes, the protein part is called:

Apoenzyme

Protoenzyme

Proenzyme

Proteino-enzyme

3. Enzymes are classified into _________classes:

Three

Five

Four

Six

4. Competitive Inhibitor is one which:

Binds close to the active site of an enzyme

Competes for the active site of an enzyme

Normally binds to active site of an enzyme

Binds away from the active site of an enzyme

5. Enzymes Oxidases and Peroxidases are included in class:

Hydrolases

Oxidoreductases

Lyases

Transferases

6. An enzyme can be synthesized by chemical bonding together molecules of

CO₂

Amino acids

Carbohydrates

Lipases

7. Enzymes are basically or all enzymes contain

Sugars

Proteins

Fats

Vitamins

8. An enzyme acts by

Increasing the pH

Decreasing the pH

Reducing the energy of activation

Increasing the energy of activation

9. Enzymes are useful to plants because.

They enhance absorption of water and salts.

They are essential for the metabolic processes

They are building blocks of chlorophyll.

They are used up in reactions.

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

They are inorganic catalyst.

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

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

They are specific both in their nature and action.

11. The important role play by enzymes during reaction is

Increase energy of activation of reaction

Lower down energy of activation of reaction

no effect on energy of activation of reaction

Maintain energy of activation of reaction

12. The organic prosthetic groups in holoenzymes are called:

Co-factors

Co-enzymes

Holo-group

Co-activators

13. Enzyme hydroxylase is included in class:

Hydrolases

Lyases

Oxidoreductases

Transferases

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

Ligases

Transferase

Lyases

Hydrolases

15. Regarding factors affecting enzyme activity, which of the following statement is correct?

pH has no effect on enzyme activity.

Substrate and enzyme concentration are directly proportional upto a certain maximum velocity.

Substrate and enzyme concentration are inversely proportional upto a certain maximum velocity.

Rate of reaction decreases with an increase in enzyme concentration until enzyme saturate.

16. Enzymes can:

React with acidic and alkaline substances both.

No react with acidic and alkaline substances as they are proteins.

React with alkaline substances only as they are proteins.

React with acidic substances only as they are proteins.

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

Esterase

Amylase

Carbonic Anhydrase

Phosphatase

18. Vitamins are essential for the body because:

They are part of some enzyme

Some activators have direct link with them

Co enzyme of enzyme is synthesized from them

Prosthetic groups of enzymes are synthesized from them

19. Substances which decrease the activity of enzyme are called:

Activators

Apo-enzymes

Inhibitors

Co-enzymes

20. At low concentration of substrate the reaction rate is directly proportional to the available.

Substrate

Coenzyme

Enzyme

Cofactor

Enzymes-Medical College Admission Test Preparation Notes