Enzymes – Online MCQs Test – Biology MCAT

1. Enzymes Oxidases and Peroxidases are included in class:

Hydrolases

Lyases

Transferases

Oxidoreductases

2. Enzymes are basically or all enzymes contain

Fats

Vitamins

Sugars

Proteins

3. Co-enzymes include:

Flavin mononucleotide

Acylglycerol

Manganese

Phospholipids

4. Concerning enzyme activity at O°C, which of the following statement is correct?

Activity is reduced to minimum but enzymes are not destroyed.

Activity is reduced to minimum but enzymes are destroyed.

Activity is increased to maximum but enzymes are destroyed.

Activity is increased to maximum but enzymes are not destroyed.

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

Substrate and enzyme concentration are directly 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.

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

6. Enzyme, Glycosidases is included in class:

Hydrolases

Transferases

Ligases

Lyases

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

Cofactor

Prosthetic group

Activator

Coenzyme

8. “When the product is in abundance, it binds competitively with enzyme’s active site, as the product is used up, more product can be produced”, this is an example of:

Competitive Inhibition

Non-competitive Inhibition

Activation

Feed-back Inhibition

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

Lipases

Amino acids

Carbohydrates

CO₂

10. The protein part of enzyme is known as

lsoenzyme

Holoenzyme

Apo-enzyme

All of the above

11. Biological control for the regulation of most of the enzyme is provided by:

Non-competitive Inhibition

Allosteric Inhibition

Competitive Inhibition

Feed-back Inhibition

12. Naturally, most of the enzymes are:

Proteins

Lipids

Vitamins

Carbohydrates

13. Which statements are correct for all enzymes?

1 and 4 only

1, 2, 3 and 4

2 and 4 only

1, 2 and 3 only

14. When an enzyme-induced product inhibits enzymatic activity, inhibition is called

Feedback inhibition

Non-competitive inhibition

None of the above

Competitive inhibition

15. Penicillin blocks the active site of an enzyme that many bacteria use for:

Synthesis of cell-wall

ATP hydrolysis

Synthesis of proteins

Cellular respiration

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

Lyases

Ligases

Transferase

Hydrolases

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

Phosphatase

Esterase

Carbonic Anhydrase

Amylase

18. Who discovered that certain molecules of ribonucleic acid also function as enzymes?

Sidney Altman & Thomas Cech

Thomas Cech only

Friedrich and Thomas Cech

Friedrich Wilhem Kuhne only

19. Enzyme hydroxylase is included in class:

Lyases

Oxidoreductases

Transferases

Hydrolases

20. Competitive Inhibitor is one which:

Binds away from the active site of an enzyme

Binds close to the active site of an enzyme

Normally binds to active site of an enzyme

Competes for the active site of an enzyme

Enzymes-Medical College Admission Test Preparation Notes