Q: Which of the following equations correctly represents the movement of water during osmosis across a selectively permeable membrane?

$$\text{Water moves from an area of low solute concentration to high solute concentration}$$

Q: The sodium-potassium pump moves ions across the plasma membrane. Which equation best represents its action?

$$3\ \text{Na}^+_{\text{inside}} \rightarrow 3\ \text{Na}^+_{\text{outside}}$$ and $$2\ \text{K}^+_{\text{outside}} \rightarrow 2\ \text{K}^+_{\text{inside}}$$

Question 1

Which of the following best describes the amphipathic nature of phospholipids in the plasma membrane?

Accepted Answer

Phospholipids have both hydrophilic and hydrophobic regions, with hydrophilic heads facing the aqueous environment and hydrophobic tails facing inward.

Question 2

A freshwater fish is adapted to cold environments. Which membrane adaptation would you expect in its cells?

Accepted Answer

A high proportion of unsaturated fatty acids in membrane phospholipids.

Question 3

Which statement about the Fluid Mosaic Model is correct?

Accepted Answer

The plasma membrane consists of a mosaic of proteins embedded in a fluid phospholipid bilayer.

Question 4

How does cholesterol affect membrane fluidity at moderate temperatures (e.g., 37°C)?

Accepted Answer

It decreases fluidity by reducing the movement of phospholipids.

Question 5

Which of the following equations correctly represents the movement of water during osmosis across a selectively permeable membrane?

Accepted Answer

$$	ext{Water moves from an area of low solute concentration to high solute concentration}$$

Question 6

A red blood cell is placed in a hypotonic solution. What will happen to the cell?

Accepted Answer

It will gain water, swell, and may lyse.

Question 7

Which type of membrane protein is most likely to function as a channel for ions?

Accepted Answer

Integral protein

Question 8

Which process requires energy input from ATP to move substances against their concentration gradient?

Accepted Answer

Active transport

Question 9

The sodium-potassium pump moves ions across the plasma membrane. Which equation best represents its action?

Accepted Answer

$$3\ 	ext{Na}^+_{	ext{inside}} ightarrow 3\ 	ext{Na}^+_{	ext{outside}}$$ and $$2\ 	ext{K}^+_{	ext{outside}} ightarrow 2\ 	ext{K}^+_{	ext{inside}}$$

Question 10

Which of the following best explains why winter wheat increases the percentage of unsaturated phospholipids in its cell membranes during autumn?

Accepted Answer

To increase membrane fluidity and prevent solidification at low temperatures.

Question 11

Which of the following is an example of secondary active transport (cotransport) in animal cells?

Accepted Answer

Glucose uptake coupled to sodium ion diffusion.

Question 12

Familial hypercholesterolemia is caused by which defect related to membrane transport?

Accepted Answer

Defective LDL receptor proteins preventing receptor-mediated endocytosis.

Question 13

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

Accepted Answer

Passive transport moves substances down their concentration gradient without energy input, while active transport moves substances against their gradient using energy.

Question 14

Which type of bulk membrane transport is used by white blood cells to engulf bacteria?

Accepted Answer

Phagocytosis

Question 15

A cell is placed in a hypertonic solution. What is the expected outcome?

Accepted Answer

Water will leave the cell, causing it to shrink.

Question 16

Which equation best represents the electrochemical gradient driving ion movement across a membrane?

Accepted Answer

$$\Delta G = RT \ln \left( \frac{[	ext{ion}]_{	ext{outside}}}{[	ext{ion}]_{	ext{inside}}} ight) + zF\Delta \Psi$$

Question 17

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

Accepted Answer

Energy storage

Question 18

Which process is responsible for the export of insulin from pancreatic cells?

Accepted Answer

Exocytosis

Question 19

Which of the following molecules can most easily cross the lipid bilayer without the aid of a transport protein?

Accepted Answer

Oxygen ($$	ext{O}_2)$$

Membrane Structure and Function: Study Notes

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드