Enzymes – Online MCQs Test – Biology MCAT

Enzymes-Medical College Admission Test Preparation Notes

MCAT Biology Notes from Chapter 7 [Enzymes] for Medical College Entry Test Preparation

1. Enzyme having different molecular arrangement but similar functions is

HoIo-enzyme

Iso-enzyme

Apo-enzyme

Co-enzyme

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

Allosteric Inhibition

Non-competitive Inhibition

Competitive Inhibition

Feed-back Inhibition

3. The organic prosthetic groups in holoenzymes are called:

Co-enzymes

Co-factors

Co-activators

Holo-group

4. Which one of the following statements regarding enzyme inhibition is correct?

Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the enzyme.

Non-competitive inhibition of an enzyme can be overcome by adding large amount of substrate

Non-competitive inhibitors often bind to the enzyme irreversibly.

Competitive inhibition is seen when a substrate competes with an enzyme for binding to an inhibitor protein.

5. Concerning effects of Radiation on enzymes:

generally inactivated by both, UV-rays and X-rays

generally activated by exposure to UV-rays & X-rays

generally activated by UV-rays and inactivated by X-rays

generally inactivated by UV-rays and activated by X-rays

6. The important role play by enzymes during reaction is

Increase energy of activation of reaction

Maintain energy of activation of reaction

Lower down energy of activation of reaction

no effect on energy of activation of reaction

7. The conversion of complex food into simpler and soluble substances by the action of enzymes is

Assimilation

Translocation

Digestion

Ingestion

8. An enzyme acts by

Increasing the pH

Decreasing the pH

Reducing the energy of activation

Increasing the energy of activation

9. Competitive Inhibitor is one which:

Normally binds to active site of an enzyme

Binds away from the active site of an enzyme

Competes for the active site of an enzyme

Binds close to the active site of an enzyme

10. Naturally, most of the enzymes are:

Vitamins

Carbohydrates

Lipids

Proteins

11. Enzymes function because of their particular shape or conformation. Which level of protein structure is most directly responsible for the shape of a protein?

Quaternary

Secondary

Primary

Tertiary

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

Co-enzymes

Co-activators

Co-factors

Ho a-group

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

They speed up the rate of biochemical reactions.

They are proteinaceous in nature.

They are used up in reactions.

They are specific in nature.

14. 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.

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.

15. Sometimes, the activator functions

Apo-enzymes

Co-enzymes

Protectors

Inhibitors

16. Coenzyme can function

Independently of the Apo-enzyme

In association with an Apo-enzyme

In association with a vitamin

In association with a protein

17. The charge and shape of the active site is formed by:

Amino acids

Globular shape

Cofactor

Allosteric site

18. Enzymes can be denatured at:

High temperature only

Low temperature & High pressure

Low pressure only

High temperature & Low pressure

19. Which of the following statements is not correct?

All enzymes are biocatalysts

All proteins are enzymes

All enzymes are proteins

All enzymes are thermo-labile

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

None of the above

Feedback inhibition

Non-competitive inhibition

Competitive inhibition

Online MCQs Test preparation for Biology MCAT (Medical College Admission Test Preparation Notes) helps students practice effectively. These multiple-choice questions are taken from Chapter 7 “Enzymes” of the Biology MCAT textbook.

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