Cell Membrane Structure and Function

1. Cell Membrane Structure and Function Hot Seat

2. Rules • You are competing against classmates in your row (across the classroom). The hot seat is the seat in each row closest to the outside windows. • Your answer must be written and you must stop writing when the teacher says, “pencils down” • After hearing the correct answer you will check your answer with the person to your left and the person to your right. • If your answer is correct and the person to your right answered incorrectly you move into their seat (towards the hot seat) and they will move into yours. • If your answer is incorrect and the person to your left answered correctly, you move into their seat (away from the hot seat) and they will move into yours. • Remember you may only move one seat at a time! If you get it right and two people in front of your get it wrong you still can only move one seat!

3. Which cell structure helps the cell maintain homeostasis by controlling what enters and leaves the cell? • Cell Membrane

4. Which section of the cell membrane is hydrophobic? • The tails of the phospholipids

5. Which section(s) of the cell membrane are hydrophilic? • The heads of the phospholipids

6. What is the difference between a solute and a solvent? • A solute is the thing being dissolved and a solvent is the liquid doing the dissolving. • Remember water is the universal solvent!

7. Which of the following would be an example of osmosis? • The smell of ammonia spreading through the room. • The shriveling of a snail after salt is poured on it • Water being poured into a glass • The absorption of water by a bathroom sponge.

8. A state of biological balance maintained by living organisms is called.. • Exocytosis • Osmosis • Homeostasis • cytolysis

9. Does the picture demonstrate passive or active transport?

10. Movement of substances across the membrane without the use of cellular energy is termed • Active transport • Carrier transport • Passive transport • Protein transport

11. Will the cell shrivel, swell, or stay the same? 95% H2O 85% H2O

12. What must a virus do to reproduce? • Invade a host cell.

13. Which of the following supports the picture shown below? • The concentration of solute in the cell was higher than in the solution so water entered the cell. • The concentration of solute in the cell was lower than in the solution so water left the cell. • The concentration of solute in the cell was higher than in the solution so water left the cell. • The concentration of solute in the cell was lower than in the solute was water entered the cell.

14. Will the cell shrivel, swell, or stay the same? 85% sugar 95% sugar

15. Which of the following supports the picture shown below? • The concentration of solute in the cell was higher than in the solution so water entered the cell. • The concentration of solute in the cell was lower than in the solution so water left the cell. • The concentration of solute in the cell was higher than in the solution so water left the cell. • The concentration of solute in the cell was lower than in the solute was water entered the cell.

16. If the cell below has a glucose concentration of 20 ppm, which of the following concentrations of the solution would cause the cell to swell? • 10 ppm • 20 ppm • 30 ppm • 40 ppm

17. Will the cell shrivel, swell, or stay the same? 84% sugar 96% sugar

18. Will the cell shrivel, swell, or stay the same? 87% sugar 87% sugar

19. If the glucose needs to be transported into the cell, will it do so by passive or active transport? • It’s active transport because the glucose is moving against the concentration gradient 52 ppm glucose 78 ppm glucose

20. Dialysis is the process by which an artificial kidney machine removes waste products from a patients’ blood. The dialysis membrane has openings that allow salts and other wastes dissolved in the blood to pass through without expending any energy. This is an example of (passive / active) transport. • Passive Transport

21. Why do grocery stores spray their produce with water? • Produce swells!

22. Why can’t you drink saltwater? • Your cells have a higher concentration of water than the saltwater. Through osmosis water leaves your cells, causing them to shrivel

23. Which of the following correctly explains the picture? • The concentration of solute in the cell was higher than in the solution so water entered the cell. • The concentration of solute in the cell was lower than in the solution so water left the cell. • The concentration of solute in the cell was equal to the concentration in the solution so water is moved into the cell • The concentration of solute in the cell was equal to the concentration in the solute so the cell is at equilibrium.

24. Inside bag A is a 50% glucose solution and inside bag B is a 30% glucose solution. Both bags are put into beakers containing 100% water. • A) Bag A will swell. • B) Bag B will swell. • C) Both bags will swell. • D) Both bags will shrivel • E) Both bags will remain the same. 100% 50% 30%

25. Which of the following correctly explains the picture? • The concentration of solute in the cell was higher than in the solution so water entered the cell. • The concentration of solute in the cell was lower than in the solution so water left the cell. • The concentration of solute in the cell was higher than in the solution so water left the cell. • The concentration of solute in the cell was lower than in the solution so water entered the cell.

26. What relationship between surface area and volume must organisms achieve to ensure efficient delivery of nutrients • keep surface area and volume equal • maximize surface area and minimize volume  • minimize surface area and maximize volume • none of these 

27. Which of the following correctly explains the picture? • The concentration of solute in the cell was higher than in the solution so water entered the cell. • The concentration of solute in the cell was lower than in the solution so water left the cell. • The concentration of solute in the cell was higher than in the solution so water left the cell. • The concentration of solute in the cell was lower than in the solution so water entered the cell.

28. Is the concentration of the solute in the solution greater than, less than, or equal to the concentration of the solute in the cytoplasm of the cell? • The concentration of solute in the solution is greater than the concentration of solute in the cytoplasm of the cell.

29. Chamber A contains 40% helium and Chamber B contains 20% helium. The chambers are connected by a tube the molecules are free to cross. Which of the following will occur? • A) Some helium will move from Chamber A to B • B) Some helium will move from Chamber B to A • C) Helium will remain concentrated in Chamber A • D) All of the helium will move to Chamber B Chamber A 40% Helium Chamber B 20% Helium

30. Cells must have ways to maintain homeostasis. Which is an example of ways cells can do this? • A) Plant cells have a cell wall to keep from bursting • B) Fresh water single-celled animals constantly pump water out • C) Eggs have shells to keep them from dehydrating • D) All of the above are examples

31. Which cell has the largest surface area to volume ratio?

32. Predict the concentration of solute on each side of the membrane after 24 hours • Equal concentration on both sides

33. Identify one difference and one similarity between facilitated diffusion and active transport? Facilitated Diffusion Active Transport Use proteins Energy Low Conc. To High Conc. Both transport bigger molecules that can’t cross through the phospholipids. • Use proteins • No Energy • High Conc. To Low Conc. • Both transport bigger molecules that can’t cross through the phospholipids.