Question 1

Which of the following best describes the function of tight junctions in epithelial tissue, as shown in the first image?

Accepted Answer

They limit paracellular transport and help maintain distinct fluid compartments.

Question 2

In the second image, which process is responsible for the movement of glucose from the lumen into the interstitial fluid?

Accepted Answer

Secondary active transport (sodium-glucose cotransport) across the apical membrane, followed by facilitated diffusion across the basolateral membrane

Question 3

Referencing the third image, what is the primary driving force for water movement across the epithelium?

Accepted Answer

Osmotic gradient created by active solute transport

Question 4

Based on the fourth image, what is the main defect in cystic fibrosis that leads to thick mucus in the airways?

Accepted Answer

Defective chloride channels in the apical membrane

Question 5

The process shown in the fifth image, where a macromolecule is transported across an epithelial cell, is called:

Accepted Answer

Transcytosis

Question 6

According to the sixth image, what is the result of the separation of charge across the plasma membrane?

Accepted Answer

The inside of the cell is negative relative to the outside.

Question 7

In the seventh image, what is the direction of the electrical driving force on a positively charged ion when the membrane potential is negative?

Accepted Answer

Inward

Question 8

In the eighth image, if the membrane potential is -70 mV and the equilibrium potential for potassium is -94 mV, what is the direction of the electrochemical driving force on potassium?

Accepted Answer

Outward

Question 9

Based on the ninth image, what happens to the net flux of molecules when the concentration on side 1 is greater than on side 2?

Accepted Answer

Net flux is from side 1 to side 2

Question 10

According to the tenth image, as the concentration gradient decreases over time, what happens to the net flux of molecules?

Accepted Answer

It decreases

Question 11

The eleventh image shows the relationship between net flux and concentration gradient for simple diffusion. What does this relationship indicate?

Accepted Answer

Net flux is directly proportional to the concentration gradient

Question 12

In the twelfth image, what effect does increased membrane permeability have on the net flux of a substance for a given concentration gradient?

Accepted Answer

It increases net flux

Question 13

The thirteenth image depicts the mechanism of facilitated diffusion. What is a key feature of this process?

Accepted Answer

It involves a carrier protein that undergoes a conformational change

Question 14

The fourteenth image shows the relationship between net flux and concentration gradient for facilitated diffusion. Why does the curve level off at high concentration gradients?

Accepted Answer

Carrier proteins become saturated

Question 15

In the fifteenth image, what is the main structural difference between a channel and a carrier protein?

Accepted Answer

Channels provide a continuous pore, while carriers undergo conformational changes to transport molecules

Question 16

The sixteenth image illustrates the sodium-potassium pump. What is the net result of one cycle of this pump?

Accepted Answer

3 Na+ out, 2 K+ in

Question 17

According to the seventeenth image, which of the following is true about simple diffusion compared to mediated transport?

Accepted Answer

Simple diffusion is not saturable, while mediated transport can be saturable

Question 18

In the eighteenth image, what happens to a red blood cell placed in pure water?

Accepted Answer

Water flows into the cell, causing it to swell and possibly burst

Question 19

The nineteenth image shows water flow between two compartments. What determines the direction of water flow?

Accepted Answer

The side with higher water concentration to the side with lower water concentration

Question 20

According to the twentieth image, what happens to a cell placed in a solution containing 150 mOsm impermeant solutes?

Accepted Answer

The cell swells to twice its original volume

Question 21

The twenty-first image shows three types of endocytosis. Which type is specific for certain molecules?

Accepted Answer

Receptor-mediated endocytosis

Question 22

In the twenty-second image, what is the main function of exocytosis?

Accepted Answer

To secrete substances from the cell and add components to the plasma membrane

Cell Membrane Transport and Epithelial Transport: Mechanisms and Clinical Relevance

Study Guide - Practice Questions

Study Guide - Flashcards