Question 1

Which of the following statements best describes the function of channel proteins in the cell membrane?

Accepted Answer

They allow passive movement of molecules down their concentration gradient, sometimes requiring gating but no energy input.

Question 2

Carrier proteins differ from channel proteins in which of the following ways?

Accepted Answer

Carrier proteins undergo conformational changes to transport molecules, while channel proteins form open pores.

Question 3

The sodium-potassium pump (Na⁺/K⁺ ATPase) is an example of:

Accepted Answer

Active transport

Question 4

Which of the following best explains why active transport requires energy input?

Accepted Answer

It moves molecules up their concentration gradient, which is energetically unfavorable.

Question 5

According to the first law of thermodynamics, which of the following is true?

Accepted Answer

Energy is neither created nor destroyed, but can change forms.

Question 6

Which of the following bonds has the highest potential energy in biological molecules?

Accepted Answer

C—H bond

Question 7

A chemical reaction is considered spontaneous if:

Accepted Answer

The change in free energy $$\Delta G is $$negative.

Question 8

Which equation correctly relates free energy change to enthalpy and entropy?

Accepted Answer

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

Question 9

Which of the following scenarios would most likely result in a spontaneous reaction?

Accepted Answer

$$\Delta H is $$negative and $$\Delta S is $$positive

Question 10

Which statement about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy, allowing reactions to occur more rapidly.

Question 11

Which of the following is true regarding the second law of thermodynamics?

Accepted Answer

Entropy of the universe tends to increase in any spontaneous process.

Question 12

A cell wants to concentrate glucose inside against its concentration gradient. Which transport mechanism would it most likely use?

Accepted Answer

Active transport using a pump protein

Question 13

Which of the following is NOT a feature of passive transport?

Accepted Answer

ATP hydrolysis is required

Question 14

If a reaction has $$\Delta H = +10 kJ/$$mol and $$\Delta S = +50 J/($$mol\cdot K)$$ at T = 300$ K, what is $$\Delta G$?

Accepted Answer

$$\Delta G = +10 - (300 	imes 0.05) = -5 kJ/$$mol

Question 15

Which of the following best describes the role of ATP hydrolysis in cellular reactions?

Accepted Answer

It provides energy to drive nonspontaneous reactions by coupling.

Question 16

Which of the following is a consequence of increasing membrane fluidity?

Accepted Answer

Increased permeability to small molecules

Question 17

Which of the following is true about the relationship between spontaneity and reaction rate?

Accepted Answer

Spontaneity ($$\Delta G \u003c 0) $$does not indicate the speed of a reaction.

Question 18

Which of the following would increase the entropy ($$S) of a $$system?

Accepted Answer

Diffusion of a solute from high to low concentration

Question 19

Which of the following is a correct statement about facilitated diffusion?

Accepted Answer

It moves molecules down their concentration gradient using carrier or channel proteins.

Question 20

Which of the following is a real-life example of coupling a nonspontaneous reaction to ATP hydrolysis?

Accepted Answer

Movement of Na⁺ ions out of a cell via Na⁺/K⁺ ATPase

Transport Proteins, Energy, and Metabolism: Key Concepts in General Biology

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