Question 1

Which of the following best describes the difference between kinetic and potential energy in biological systems?

Accepted Answer

Kinetic energy is the energy of motion, such as thermal energy, while potential energy is stored in position or configuration, such as chemical energy in bonds.

Question 2

According to the first law of thermodynamics, which statement is correct regarding energy in chemical reactions?

Accepted Answer

Energy is conserved; it cannot be created or destroyed, only transferred and transformed.

Question 3

Which type of chemical bond has the highest potential energy?

Accepted Answer

Weak nonpolar bonds with equally shared electrons.

Question 4

What does a negative value for enthalpy ($$\Delta H \u003c 0) $$indicate about a chemical reaction?

Accepted Answer

The products have lower potential energy than the reactants and heat is released.

Question 5

Which equation correctly relates Gibbs free energy to enthalpy, entropy, and temperature?

Accepted Answer

$$\Delta G = \Delta H - T\Delta S$$

Question 6

A reaction is considered spontaneous if:

Accepted Answer

$$\Delta G \u003c 0$$

Question 7

Which of the following best describes the role of enzymes in chemical reactions?

Accepted Answer

Enzymes lower the activation energy, allowing reactions to proceed faster.

Question 8

Which statement about enzyme specificity is correct?

Accepted Answer

Enzymes are specific for a single type of reaction and substrate.

Question 9

What is the effect of increasing substrate concentration on the rate of an enzyme-catalyzed reaction?

Accepted Answer

The reaction rate increases linearly at low substrate concentrations, then levels off at high concentrations due to enzyme saturation.

Question 10

Which of the following is an example of competitive inhibition?

Accepted Answer

A molecule competes with the substrate for binding at the enzyme's active site.

Question 11

Which statement about ATP hydrolysis is correct?

Accepted Answer

ATP hydrolysis forms ADP and inorganic phosphate, releasing energy.

Question 12

How does phosphorylation typically affect a protein?

Accepted Answer

It causes a change in the protein's shape, which may activate or inactivate the protein.

Question 13

Which of the following is true about metabolic pathways?

Accepted Answer

Catabolic pathways break down large molecules into small ones, releasing energy.

Question 14

Which molecule acts as a coenzyme in redox reactions, transferring electrons?

Accepted Answer

NADH

Question 15

What is the main function of feedback inhibition in metabolic pathways?

Accepted Answer

To shut down a pathway when the final product is no longer needed by the cell.

Question 16

Which of the following best describes the induced fit model of enzyme function?

Accepted Answer

The enzyme undergoes a conformational change when the substrate binds, improving the fit.

Question 17

Which factor does NOT directly affect enzyme activity?

Accepted Answer

The color of the enzyme

Question 18

In a redox reaction, what happens during oxidation?

Accepted Answer

A molecule loses electrons.

Question 19

Which statement about enzyme regulation is correct?

Accepted Answer

Allosteric regulation involves a molecule binding to a site other than the active site, changing enzyme shape and activity.

Energy and Enzymes: An Introduction to Metabolism (General Biology Study Notes)

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