1.4 - Membrane Transport

Which one of the following transport proteins only carries out active transport?

• A. $\hspace{1em}$ Protein channels

• B. $\hspace{1em}$ Protein pumps

• C. $\hspace{1em}$ Protein carriers

• D. $\hspace{1em}$ Aquaporins

Which of the following types of membrane transport do not require energy expenditure?

• I. $\hspace{1em}$ Facilitated diffusion
• II. $\hspace{.7em}$ Active transport
• III. $\hspace{.4em}$ Osmosis

• A. $\hspace{1em}$ II only

• B. $\hspace{1em}$ I and II

• C. $\hspace{1em}$ I and III

• D. $\hspace{1em}$ I only

Below is a diagram showing three red blood cells that have been placed in solutions of different solute concentrations.

[© Revision Village. 2023 Created with BioRender.com]

Which row correctly matches each cell with the type of solution that it has been immersed in?

[Maximum mark: 10]

Neuronal cells have special membrane properties that allow their axons to propagate action potential from one cell to another. The diagram below shows a portion of an axonal plasma membrane.

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1. 1. State the role of a sodium-potassium pump in the axon. [1]
      

   2. Describe the action of the sodium-potassium pump. [3]
      

2. Distinguish between simple diffusion, facilitated diffusion and active transport. [2]
   

3. Compare and contrast sodium-potassium pumps and voltage-gated potassium channels. [4]
   

Which statement best describes the osmotic concentration of a solution used to bathe organs for use in organ transplant procedures?

• A. $\hspace{1em}$ The solution must have an osmotic concentration higher than that of the organ to be transplanted.

• B. $\hspace{1em}$ The solution must have an osmotic concentration lower than that of the organ to be transplanted.

• C. $\hspace{1em}$ The solution must be isotonic compared to the cells of the organ to be transplanted.

• D. $\hspace{1em}$ The solution must be mixed with cells from the organ to be transplanted.

Which process is most likely responsible for the origin of mitochondria as a eukaryotic cell organelle?

• A.$\hspace{1em}$ Osmosis

• B.$\hspace{1em}$ Exocytosis

• C.$\hspace{1em}$ Apoptosis

• D.$\hspace{1em}$ Endocytosis

What type of transport is depicted in the image below?

[Source: Adapted from Laboratoires Servier (2019, September 29). File: Endocytosis_2_--_Smart-Servier.png - wikimedia commons. Wikimedia commons. Retrieved September 20, 2023, from https://commons.wikimedia.org/wiki/File: Endocytosis_2_--_Smart-Servier.png Copyright under CC BY 3.0]

• A.$\hspace{1em}$ Active transport

• B.$\hspace{1em}$ Simple diffusion

• C.$\hspace{1em}$ Facilitated diffusion

• D.$\hspace{1em}$ Exocytosis

[Maximum mark: 10]

Below is a diagram showing the response of red blood cells when placed in different solute concentrations.

[Source: Adapted from Zephyris (2012, February 16). Tonicity-Tonicity. Wiki. Retrieved July 24th, 2023, from https://en.wikipedia.org/wiki/File: Human_Erythrocytes_OsmoticPressure_PhaseContrast_Plain.svg. CC 3.0.]

1. State what is meant by the term isotonic solution. [1]
   

2. Identify which concentrations were hypotonic and which were hypertonic to the red blood cells. [2]
   

3. If red blood cells were placed in a hypotonic solution, explain the likely changes in ion concentration in the cytoplasm of the cells. [2]
   

4. Describe the process of how a solid granule of NaCl becomes a solute when placed in water. [2]
   

5. Compare and contrast how animal and plant cells are affected by being placed in hypotonic solutions and hypertonic solutions. [3]
   

The image below shows red blood cells placed in three different solutions as seen under the light microscope. Which type of solution were the cells shown in micrograph A most likely placed in?

[Source: Adapted from Zephyris. (2012). Human Erythrocytes Osmotic Pressure Phase Contrast Plain [Micrograph]. Retrieved April 21, 2022, from https://commons.wikimedia.org/w/index.php?curid=18401754. Copyright under CC BY-SA 3.0]

• A. $\hspace{1em}$ A hypertonic solution

• B. $\hspace{1em}$ A hypotonic solution

• C. $\hspace{1em}$ An isotonic solution

• D. $\hspace{1em}$ Distilled water

Which of the following statements does not describe a step in the sodium-potassium pump cycle in the neuronal cells?

• A. $\hspace{1em}$ Three sodium ions attach to their binding sites in the pump from the interior of the cell.

• B. $\hspace{1em}$ The pump changes shape upon being phosphorylated, and sodium ions are released to the outside.

• C. $\hspace{1em}$ Three potassium ions attach to their binding sites in the pump from the exterior of the cell.

• D. $\hspace{1em}$ The pump changes shape upon releasing the phosphate group, and potassium ions are released to the interior of the cell.

The diagram represents two solutions with different water potentials separated by a selectively permeable membrane.

[© Revision Village 2023]

Select the row with the correct direction for the net movement of water molecules and the correct reason for the movement.

[Maximum mark: 16]

Membrane transport is important for allowing particles to move across the cell membrane and respond to changes in the chemical composition of the extracellular fluid.

1. Outline the effects of placing a liver cell in a hypotonic solution. [3]
   

2. Outline how the fluidity of membranes allows materials to be taken into cells or to be released from cells. [5]
   

3. Compare and contrast four types of membrane transport. Include an example of each. [7]
   

Which statement describes endocytosis?

• A.$\hspace{1em}$ Protein-containing vesicles from the Golgi apparatus fusing with the cell membrane

• B.$\hspace{1em}$ The contractile vacuole in Paramecium expelling water

• C.$\hspace{1em}$ Oxygen diffusing from a red blood cell to a respiring tissue

• D.$\hspace{1em}$ Antibodies from the mother’s blood being taken up by the placenta

The image below shows red blood cells placed in an isotonic solution and a solution of unknown solute concentration. Which type of solution is that of unknown concentration, and what effect does this have on the volume of the cells?

[Source: Adapted from Zephyris. (2012). Human Erythrocytes Osmotic Pressure Phase Contrast Plain [Micrograph]. Retrieved April 21, 2022, from https://commons.wikimedia.org/w/index.php?curid=18401754. Copyright under CC BY-SA 3.0]

[Maximum mark: 10]

In an investigation into the effect of solute concentration on diffusion rate, starch solutions, of varying concentrations, were placed inside starch permeable membrane balloons. Each balloon was put into a beaker of distilled water and at 3 minute intervals, samples were taken from the solution surrounding the membrane balloons in each beaker, placed on spotting tiles and tested for the presence of starch. The time taken for a positive test to show was recorded for each trial.

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The results are shown in the graph.

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1. 1. Identify the dependent and independent variable in this investigation. [2]
      

   2. State one variable, other than time of testing, that should be kept constant in this investigation to ensure the results are valid. [1]
      

2. Describe a positive test for starch. [1]
   

3. Explain why the method used in this study would not be appropriate for an investigation into the effects of solute concentration on active transport. [2]
   

4. 1. Samples taken from the 5% and 10% starch solution both tested positive for starch after 3 minutes. Suggest a way in which the experiment could be improved to provide a more accurate result. [1]
      

   2. Predict the time taken for a positive starch test for a starch concentration of 3%. [1]
      

5. Suggest modifications to the methodology that would make it suitable to investigate the effect of glucose concentration on the rate of diffusion. [2]
   

[Maximum mark: 10]

The graph shows the results of an experiment on osmosis in potato tissue (Solanum tuberosum), cactus tissue (Carnegiea gigantea) and sunflower seeds (Helianthus annuus). Similar sized pieces of tissue were immersed in different solutions of sucrose for 30 hours.

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1. Estimate the concentration of sucrose that is isotonic to the interior of the potato tissue. [1]
   

2. Using the graph deduce, with a reason, the tissue that has the highest solute concentration. [1]
   

3. Suggest one reason for the difference in internal solute concentration between the sunflower seed and cacti tissue. [1]
   

4. The epidermis of the potato and cactus and the testa of the sunflowers seeds were removed. Suggest a reason for this. [1]
   

5. Predict what the appearance of the cacti tissue would be like at 0.5 mol dm-3 sucrose solution. [1]
   

6. 1. State how percentage change in mass is calculated. [1]
      

   2. Explain why percentage change in mass is calculated rather than change in mass. [2]
      

7. Explain why temperature has to be controlled in this study. [1]
   

8. State one way in which this experiment could be made more reliable. [1]
   

Which of the following surface area to volume ratios would result in the highest rate of diffusion for a cell?

• A. $\hspace{1em}$ The higher the surface area to volume ratio, the higher the rate of diffusion

• B. $\hspace{1em}$ The lower the surface area to volume ratio, the higher the rate of diffusion

• C. $\hspace{1em}$ The higher the volume to surface area ratio, the higher the rate of diffusion

• D. $\hspace{1em}$ The lower the volume to surface area ratio, the lower the rate of diffusion

[Maximum mark: 10]

Organelles are adapted for their function(s). The diagram shows the basic structure of a chloroplast.

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1. 1. Identify the structures labelled II and IV in the diagram. [1]
      

   2. Using the labels from the diagram, identify a location with a large surface area and where a concentration gradient is established. [1]
      

2. Identify three similarities between the mitochondrial and chloroplast structure. [3]
   

3. Outline the roles of the rough endoplasmic reticulum and the Golgi apparatus in protein production. [3]
   

4. Outline the formation and function of vesicles. [2]
   

Which type of transport is represented by this diagram?

[© Revision Village 2023. Created with BioRender.com]

• A. $\hspace{1em}$ Active transport

• B. $\hspace{1em}$ Simple diffusion

• C. $\hspace{1em}$ Facilitated diffusion

• D. $\hspace{1em}$ Protein channel

[Maximum mark: 16]

1. Draw a labelled diagram of the fluid mosaic model of the plasma membrane of an animal cell. [4]
   

2. Explain how type I and type II pneumocytes are adapted to their functions. [4]
   

3. Describe how cell surface membranes regulate the movement of substances into and out of animal cells. [7]
   

The graph below shows the change in mass of a potato slice (%) at different concentrations of sucrose solution ($mol$ $dm^{-3}$).

[ © Revision Village 2022]

Which of the concentrations is the closest estimate of the molarity of the potato cells?

• A. $\hspace{1em}$ 0.01 $mol$ $dm^{-3}$

• B. $\hspace{1em}$ 0.22 $mol$ $dm^{-3}$

• C. $\hspace{1em}$ 0.38 $mol$ $dm^{-3}$

• D. $\hspace{1em}$ 0.57 $mol$ $dm^{-3}$

Which row about the different methods of membrane transport is incorrect?

Given the following experimental set-up, in which direction will there be a net movement of water?

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• A. $\hspace{1em}$ Water will diffuse out of the cell.

• B. $\hspace{1em}$ Water will diffuse into the cell.

• C. $\hspace{1em}$ Water will diffuse equally into and out of the cell.

• D. $\hspace{1em}$ Water will not move.

Which organelle is formed by a vesicle derived from the cell membrane?

• A.$\hspace{1em}$ Food vacuole

• B.$\hspace{1em}$ Ribosome

• C.$\hspace{1em}$ Golgi apparatus

• D.$\hspace{1em}$ Smooth endoplasmic reticulum

What type of transport is pinocytosis?

• A. $\hspace{1em}$ Endocytosis, which is a form of active transport

• B. $\hspace{1em}$ Endocytosis, which is a form of passive transport

• C. $\hspace{1em}$ Exocytosis, which is a form of active transport

• D. $\hspace{1em}$ Exocytosis, which is a form of passive transport