Q: Which equation best represents the movement of water during osmosis across a selectively permeable membrane?

$$\text{Water moves from a region of lower solute concentration to higher solute concentration}$$

Question 1

Which of the following best describes the fluid mosaic model of the plasma membrane?

Accepted Answer

A fluid structure with a mosaic of various proteins embedded in or attached to a bilayer of phospholipids.

Question 2

Phospholipids are described as amphipathic molecules. What does this mean?

Accepted Answer

They contain both hydrophobic and hydrophilic regions.

Question 3

Which of the following statements about membrane fluidity is correct?

Accepted Answer

Membranes must be fluid to work properly; typically, they are about as fluid as salad oil.

Question 4

A human cell is placed in a solution with a higher solute concentration than inside the cell. What will happen to the cell?

Accepted Answer

It will lose water and shrivel.

Question 5

Which type of membrane protein is most likely to be involved in signal transduction?

Accepted Answer

Integral protein

Question 6

What is the main function of aquaporins in the plasma membrane?

Accepted Answer

Facilitate the diffusion of water.

Question 7

Which equation best represents the movement of water during osmosis across a selectively permeable membrane?

Accepted Answer

$$	ext{Water moves from a region of lower solute concentration to higher solute concentration}$$

Question 8

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

Accepted Answer

Synthesis of phospholipids

Question 9

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

Accepted Answer

The cell will become turgid.

Question 10

Which process requires energy input from the cell?

Accepted Answer

Active transport

Question 11

The sodium-potassium pump is an example of:

Accepted Answer

Active transport

Question 12

Which of the following best explains why hydrophobic molecules can cross the plasma membrane more easily than hydrophilic molecules?

Accepted Answer

Hydrophobic molecules dissolve in the lipid bilayer.

Question 13

What is the role of cholesterol in the plasma membrane at cool temperatures?

Accepted Answer

It increases membrane fluidity by preventing tight packing of phospholipids.

Question 14

Which of the following is true about the sidedness of membranes?

Accepted Answer

The asymmetrical distribution of proteins, lipids, and carbohydrates is determined during membrane synthesis by the ER and Golgi apparatus.

Question 15

Which of the following best describes receptor-mediated endocytosis?

Accepted Answer

A process where binding of ligands to receptors triggers vesicle formation.

Question 16

Which equation describes the electrochemical gradient that drives ion diffusion across a membrane?

Accepted Answer

$$\Delta G = RT \ln \left( \frac{[C]_2}{[C]_1} \right) + zF\Delta \Psi$$

Question 17

Which of the following is a real-life example of osmoregulation in unicellular organisms?

Accepted Answer

A Paramecium using a contractile vacuole to pump out excess water.

Question 18

Which of the following statements about facilitated diffusion is correct?

Accepted Answer

It involves transport proteins that speed the passive movement of molecules across the membrane.

Question 19

Which process is used by secretory cells to export their products?

Accepted Answer

Exocytosis

Question 20

A cell is placed in a solution containing 0.03 M sucrose, while the cell's internal concentration is 0.01 M sucrose. Predict the net movement of water.

Accepted Answer

Water will move out of the cell.

Membrane Structure and Function: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard