Question 1

Which of the following best describes the primary function of an enzyme in a biological reaction?

Accepted Answer

To lower the activation energy required for the reaction.

Question 2

Which effect is responsible for lowering the activation energy by inducing strain on the bonds of the substrate?

Accepted Answer

Energy effect

Question 3

Which class of enzyme catalyzes the transfer of a phosphoryl group ($$ -PO_3^{2-} ) $$between substrates?

Accepted Answer

Kinase

Question 4

Which subclass of hydrolases is responsible for digesting proteins by hydrolyzing peptide bonds?

Accepted Answer

Proteases

Question 5

Which enzyme class catalyzes the rearrangement of atoms within a molecule to produce an isomer?

Accepted Answer

Isomerases

Question 6

Which class of enzymes requires ATP hydrolysis to provide energy for the reaction to occur?

Accepted Answer

Ligases

Question 7

A scientist is studying an enzyme that catalyzes the removal of two hydrogen atoms from a substrate to form a double bond. Which coenzyme is most likely required for this reaction?

Accepted Answer

NAD^+ or FAD

Question 8

Which statement best explains why the induced fit model is more accurate than the lock-and-key model for enzyme-substrate binding?

Accepted Answer

The substrate forces the enzyme to change shape, optimizing binding and catalysis.

Question 9

Which of the following statements about enzyme specificity is correct?

Accepted Answer

Highly specific enzymes catalyze one type of reaction for a single substrate.

Question 10

Which of the following best describes the effect of increasing substrate concentration on enzyme activity when enzyme concentration is constant?

Accepted Answer

The reaction rate increases and then levels off at a maximum value.

Question 11

A patient is diagnosed with a genetic mutation that causes their body to produce a defective coenzyme. Which of the following is a likely consequence?

Accepted Answer

The enzyme will remain as an apoenzyme and be catalytically inactive.

Question 12

Which of the following best describes the effect of temperature on enzyme activity?

Accepted Answer

Enzyme activity is highest at an optimal temperature and decreases at temperatures above or below this value.

Question 13

Which of the following is true regarding the role of enzymes in chemical reactions?

Accepted Answer

Enzymes can be modified during the reaction but return to their original state after the reaction is complete.

Question 14

Which of the following best describes the role of a cofactor in enzyme catalysis?

Accepted Answer

A cofactor is a nonprotein substance required for enzyme activity.

Question 15

A researcher adds more enzyme to a reaction mixture with excess substrate. What is the expected effect on the reaction rate?

Accepted Answer

The reaction rate will increase proportionally with enzyme concentration.

Question 16

Which of the following is a real-life example of a transferase enzyme?

Accepted Answer

Phosphofructokinase transferring a phosphate group to fructose-6-phosphate

Question 17

Which of the following statements about enzyme-substrate binding is correct?

Accepted Answer

The substrate induces a conformational change in the enzyme upon binding.

Question 18

Which of the following best describes the difference between a highly specific enzyme and a nonspecific enzyme?

Accepted Answer

Highly specific enzymes catalyze one reaction for a single substrate, while nonspecific enzymes catalyze one reaction for a group of similar substrates.

Question 19

Which of the following scenarios best illustrates the effect of substrate concentration on enzyme activity?

Accepted Answer

A pizza party with unlimited pizza (substrate) and only a few students (enzymes) reaches a maximum rate of pizza consumption.

Question 20

Would the human form of trypsin be active in a thermophile organism that lives at 75 $$ ^\circ \mathrm{C} $$?

Accepted Answer

No, because human trypsin denatures at high temperatures.

Enzyme Classification and Regulation: GOB Chemistry Study Notes

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