Question 1

Which level of protein structure is primarily stabilized by hydrogen bonds between the peptide backbone, and what is a common example of this structure?

Accepted Answer

Secondary structure; alpha-helix

Question 2

A cell is placed in a solution containing 1.0 M glucose on one side of a semipermeable membrane and 0.5 M glucose on the other. Which direction will water move, and what is the process called?

Accepted Answer

Water will move from 0.5 M to 1.0 M by osmosis

Question 3

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

Accepted Answer

They allow specific molecules to diffuse passively across the membrane

Question 4

Which equation best represents the rate of diffusion across a membrane, given concentration difference $$C_1$$ - $$C_2$$ and distance $$d$$?

Accepted Answer

$$ \frac{C_1 - C_2}{d} $$

Question 5

A red blood cell is placed in pure water. What will happen to the cell, and why?

Accepted Answer

It will swell and possibly burst because water enters the cell by osmosis

Question 6

Which of the following statements about the cell membrane is correct?

Accepted Answer

It is selectively permeable, allowing some molecules to pass while blocking others

Question 7

Which process requires energy input from the cell to move molecules across the membrane?

Accepted Answer

Active transport

Question 8

According to the second law of thermodynamics, what happens to the entropy of a closed system over time?

Accepted Answer

Entropy increases

Question 9

Which of the following best describes an exergonic reaction?

Accepted Answer

A reaction that releases energy and has $$\Delta G \u003c 0$$

Question 10

A scientist observes that a solute moves from an area of high concentration to an area of low concentration across a membrane without energy input. Which process is being observed?

Accepted Answer

Simple diffusion

Question 11

Which of the following is a correct statement about osmosis?

Accepted Answer

Osmosis is the movement of water from low solute concentration to high solute concentration

Question 12

Which of the following best explains why the Na+/K+ ATPase pump is considered an example of active transport?

Accepted Answer

It requires energy from ATP to move ions against their concentration gradients

Question 13

If a cell membrane's surface area is doubled, what happens to the rate of diffusion across the membrane, assuming all other factors remain constant?

Accepted Answer

The rate of diffusion is doubled

Question 14

Which of the following is NOT a function of proteins in the cell membrane?

Accepted Answer

Storing genetic information

Question 15

A solution contains 0.25 M glucose on one side of a semipermeable membrane and 0.5 M glucose on the other. Which side has higher osmotic pressure, and what is the expected net movement of water?

Accepted Answer

0.5 M side; water moves toward 0.5 M

Question 16

Which of the following best describes the difference between facilitated diffusion and active transport?

Accepted Answer

Facilitated diffusion moves molecules down their gradient without energy; active transport moves them against their gradient using energy

Question 17

Which of the following is a real-world example of an exergonic reaction in the human body?

Accepted Answer

Hydrolysis of ATP to ADP and inorganic phosphate

Question 18

Which of the following statements about the law of conservation of energy is correct?

Accepted Answer

Energy cannot be created or destroyed, only transformed

Question 19

Which of the following best describes the quaternary structure of a protein?

Accepted Answer

The association of multiple polypeptide chains to form a functional protein complex

Question 20

A patient is given an intravenous solution that is hypertonic relative to their blood plasma. What is the most likely effect on their red blood cells?

Accepted Answer

The cells will shrink as water leaves them

Protein Structure and Cellular Transport: Key Concepts in General Biology

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