Transport Across the Cell Membrane

Transport Across the Cell Membrane Name __ _ Date __09/02/2021_______ Study the diagrams below. Note the concentrations of the various solutions. The membrane is permeable to both water and glucose. A. Hypertonic B. Hypotonic. C. Isotonic. 1. Draw arrows indicating the net movement of each material. 2. Is the solution in the beaker isotonic, hypertonic or hypotonic to the solution in the bag? Label each solution under the picture. 3. Are these substances moving across the membrane by active or passive transport? Explain. Passive transport. An example is water diffusion. 4. Describe how the appearance of the bag at “A” might change after a period of time has passed. The bag will shrink after time due to the water leaving. 5. Describe how the appearance of the bag at “B”” might change after a period of time has passed. The bag is going to extend due to the water traveling into the bag. 6. Describe how the appearance of the bag at “C”” might change after a period of time has passed. The bag is going to stay the same due to the isotonic solution. 7. What will happen to the movement of water and glucose when both sides of the membrane have reached equilibrium? The solution will be isotonic at the ‘same strength’. 8. What molecule is largely responsible for the changes in volume of these bags? The red blood cells in your blood must constantly be in an isotonic condition. A 0.9% salt solution is isotonic to red blood cells. 9. Draw a simple sketch of a red blood cell in an isotonic solution. Label the inside and the outside of the cell with the correct concentrations of salt and water. The amount of water going into the cell is the same as the amount going out of the cell. The salt inside the cell is the same as the solution outside. 1 10. Explain what will happen to the red blood cell if it is placed in a solution that is 99.3% water and 0.7% salt. Is the cell hypertonic or hypotonic to the solution? It would be hypotonic. Water is going to move into the cell causing it to swell and bust. 11. Explain what will happen to the red blood cell if it is placed in a solution that is 90% water and 10% salt. Is the cell hypotonic or hypertonic to the solution? It would be hypertonic. Water will rush into the cell causing it to bust. 12. What happens to an animal cell that is placed in a hypotonic solution? What is this condition called? The cell will swell and bust. This is called cytolysis. 13. What happens to a plant cell when placed in a hypotonic solution? What is this condition called? The osmotic pressure will increase. The cell will swell but not bust. This is called plasmolysis. 14. Account for these differences in plant cells and animal cells in questions 12 and 13. 15. Describe what would happen to a cell that was placed in a hypertonic solution. Would it matter if the cell were a plant cell or animal cell? Both animal and plant cells will shrink in a hypertonic solution. 16. What would happen to the cell if it were placed in Beaker A? The solution would be hypertonic. The cell would shrink. Beaker B? The solution would be isotonic. No change would occur. Beaker C? The solution would be hypotonic. Water goes into the Cell causing it to bust. Beaker D? The solution would be hypotonic. 17. Which solution is isotonic to the cell? Solution B 18. Which solution(s) are hypertonic to the cell? Solution A 19. Which solution(s) are hypotonic to the cell? Solution C & D 20. What is the purpose of the membrane surrounding the lysosome? Is active or passive transport being used here? Explain. The lysosome contains enzymes that become active in acidic ph. The membrane contains proton pumps which increases the lysosome hydrogen, which then transports the hydrogen from the cytoplasm to the lysosome increasing acidity. 2 21. Three different processes are occurring in the drawing below. Name each process and describe it. Simple diffusion Passive Transport Facilitated diffusion Protein Pump (Active Transport) 22. Referring to the drawing to the right: The beaker contains a 25% salt solution and the bag contains pure water. Label the drawing. 23. What is the concentration of water in the beaker? 75% 24. Is the bag hypotonic or hypertonic to the beaker? Hypotonic. 25. Is the beaker hypotonic or hypertonic to the bag? Hypertonic. 26. In which direction will water move? From the bag to the beaker. 27. What condition might occur if too much water moves out? The bag will shrink 28. The movement of salt and water will continue until? Until the concentration is equal. 29. After equilibrium has been reached, what will happen to the movement of these molecules? Particles will keep moving in each direction. 30. Referring to the drawing to the right: The beaker contains a 5% salt solution and the bag contains a 15% salt solution. Label the drawing. 31. What is the concentration of water in the beaker? 95% 32. What is the concentration of the water in the bag? 85% 33. Is the bag hypotonic or hypertonic to the beaker? Hypertonic 34. Is the beaker hypotonic or hypertonic to the bag? Hypotonic 35. In which direction will water move? Towards the bag (inward) 36. What condition might occur if too much water moves in? the water might go into cytolysis and explode. 37. The movement of salt and water will continue until? equilibrium is reached. 38. After equilibrium has been reached, what will happen to the movement of these molecules? Movement will continue but equilibrium will be maintained. 39. Below is a drawing of a typical membrane. Label each of the following in the drawing: Phospholipids, Lipid bilayer, proteins, transport proteins, carbohydrates, cholesterol. Carbohydrates Lipid bilayer proteins Phospholipid Cholesterol Transport Proteins 4