Enzymes – Online MCQs Test – Biology MCAT

1. Which statements are correct for all enzymes?

1 and 4 only

2 and 4 only

1, 2 and 3 only

1, 2, 3 and 4

2. The protein part of enzyme is known as

lsoenzyme

Apo-enzyme

All of the above

Holoenzyme

3. In non-competitive inhibition, the binding site other than the active site is called:

Allosteric site

Prosthetic site

Allo-enzyme site

Prosteric site

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

Non reversible

Feedback inhibition

Competitive inhibition

Non-competitive inhibition

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

Amylase is an enzyme which entirely consists of protein.

Conjugated enzyme consists of non-protein part.

Enzymes are modified lipids.

Simple enzyme consists of protein and non-protein part.

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

Esterase

Amylase

Carbonic Anhydrase

Phosphatase

7. Synthetases are enzymes included in class:

Transferase

Hydrolases

Ligases

Lyases

8. Non-protein part of an enzyme is Known as

Holoenzyme

All of the above

Apoenzyme

Coenzyme

9. A cofactor made of inorganic ion which is detachable is called

Coenzyme

Cofactor

Activator

Prosthetic group

10. Regarding enzyme molecules:

Of same size as substrate

Greater in size than the substrate

Smaller in size than the substrate

No relation with substrate

11. All of the following are correct about enzymes EXCEPT

Enzymes lower the energy of activation

Enzymes are assisted by cofactors

Enzymes are affected by changes in temperature but not changes in pH

Enzymes are organic catalysts

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

Apoenzyme

Proteino-enzyme

Proenzyme

Protoenzyme

13. Enzymes can be denatured at:

High temperature only

Low pressure only

Low temperature & High pressure

High temperature & Low pressure

14. Enzyme having different molecular arrangement but similar functions is

Apo-enzyme

Iso-enzyme

Co-enzyme

HoIo-enzyme

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

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

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

pH has no effect on enzyme activity.

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

16. Enzymes are classified into _________classes:

Four

Five

Six

Three

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

18. Vitamins are essential for the body because:

Prosthetic groups of enzymes are synthesized from them

Co enzyme of enzyme is synthesized from them

Some activators have direct link with them

They are part of some enzyme

19. Most vitamins are:

Competitive inhibitors

Non-competitive inhibitors

Co-factors

Co-enzymes

20. Who is credited with proposing ‘Lock and Key’ theory?

Emil Fischer

Buchner

Summer

Koshland

Enzymes-Medical College Admission Test Preparation Notes