Question 1

A red blood cell is placed in a solution with a lower osmolarity than its cytoplasm. What is most likely to happen to the cell?

Accepted Answer

The cell will swell and possibly burst as water enters by osmosis.

Question 2

Which of the following best defines facilitated diffusion?

Accepted Answer

Passive movement of solutes through a membrane via specific transport proteins.

Question 3

According to Fick’s Law, which of the following changes would increase the rate of diffusion across a membrane?

Accepted Answer

Increasing the concentration gradient across the membrane.

Question 4

In the PhysioEx experiment, which solute displayed the highest rate of diffusion through the 200 MWCO membrane?

Accepted Answer

NaCl

Question 5

What is the relationship between solute size and rate of diffusion through a membrane?

Accepted Answer

Smaller solutes diffuse faster than larger solutes.

Question 6

Which of the following is true regarding osmosis?

Accepted Answer

Osmosis is the movement of water across a selectively permeable membrane.

Question 7

If NaCl can freely diffuse across a membrane, what happens to osmotic pressure?

Accepted Answer

No osmotic pressure is generated.

Question 8

Which MWCO membrane had the greatest filtration rate in the PhysioEx experiment?

Accepted Answer

200 MWCO

Question 9

What effect does increasing the driving pressure have on filtration rate?

Accepted Answer

Filtration rate increases.

Question 10

How does blood pressure affect filtration in the kidneys?

Accepted Answer

Higher blood pressure increases filtration rate.

Question 11

Which solute did not appear in the filtrate using any of the membranes in the PhysioEx experiment?

Accepted Answer

Albumin

Question 12

Which of the following best defines active transport?

Accepted Answer

Movement of solutes against their concentration gradient using ATP.

Question 13

In the PhysioEx experiment, with 1 mM ATP added to the cell interior, was all the Na+ moved into the extracellular space? Why or why not?

Accepted Answer

No, because the number of sodium-potassium pumps limits transport.

Question 14

What is the effect of decreasing the number of sodium-potassium pumps in a cell?

Accepted Answer

The rate of sodium transport decreases.

Question 15

How can you demonstrate that sodium movement is due to active transport and not simple diffusion?

Accepted Answer

By showing sodium moves only when ATP is present.

Question 16

Which of the following is a way to increase the rate of glucose transport via facilitated diffusion?

Accepted Answer

Increase the number of glucose transport proteins.

Question 17

Did NaCl require a transport protein for diffusion in the PhysioEx experiment?

Accepted Answer

No, because NaCl can diffuse through the membrane without a protein.

Question 18

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

Accepted Answer

Cells will shrink as water leaves.

Question 19

Which equation represents Fick’s Law of Diffusion?

Accepted Answer

$$J = -D \frac{dC}{dx}$$

Question 20

A cell is placed in an isotonic solution. Which of the following best describes what happens?

Accepted Answer

There is no net movement of water; the cell remains unchanged.

Cell Membrane Transport Lab: Step-by-Step Study Guidance

Study Guide - Practice Questions