I need help completing this review sheet. I’m having trouble


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I need help completing this review sheet. I’m having trouble answering the short answers. If u could also help me with the multiple choice questions. Thank you Attachment 1 Attachment 2 ATTACHMENT PREVIEW Download attachment PracticeQuestionsSet4.pdf Practice Questions Set 4 Membranes and Transport 1. In any given cell or membrane-bound organelle, the lipid bilayer surrounds an aqueous solution with other particles or units inside it. What is the primary function of the lipid bilayer membrane for any given cell or membrane-bound organelle? How does the structure of the lipid bilayer relate to this function? Consider the role of the phosphate heads, the fatty acid tails and the embedded proteins. 2. Compare and contrast simple diffusion, facilitated diffusion, and active transport. 3. Biological membranes are described as both fluid and a mosaic. Explain what these terms mean in terms of the components of the membranes. 4. Explain why lateral drift of lipids in a membrane happens so much more often than transverse flip-flop. 5. Review the figure relating to the experiment by Frye and Edidin (membrane fusion experiment). State: a. What is the big question being asked? b. What is one alternative hypothesis? c. What is the null hypothesis for the alternative hypothesis you wrote above? d. What is the experimental prediction based on the alternative hypothesis you wrote above? 6. List 1 example of the types of molecules that can cross the membrane on their own. 7. Look at the figure for aquaporins from the lecture notes. Explain which parts of the protein have to be hydrophilic versus hydrophobic. What in the protein structure allows for these differences? 8. Explain the difference between channels and carrier proteins. 9. Explain why the sodium-potassium pump in animals and the proton pump in plants are considered to be electrogenic. 10. Carbon dioxide molecules typically cross the cell membrane by way of a. simple diffusion b. a channel protein c. a cotransporter d. a carrier protein 11. Review the figure of the K+ voltage-gated channel in your textbook. Where is the mistake in the figure? 12. Compare and contrast active transport of Na+ through a Na+/K+ pump and active transport of glucose through a Na+/glucose symporter. 13. A cell has a potential of -70 mV (negative inside). Therefore, positively charged ions such as K+ will enter the cell through K+ channels via passive transport. Is this statement correct? Explain your answer. 14. What is membrane potential? 15. What is meant by the “electrochemical” gradient? 16. Compare and contrast symport and antiport. 17. A mutation causes the amino acids that normally line the tunnel part of aquaporins in an organism to be replaced with the following amino acids: valine, isoleucine, and leucine. Review (do not memorize) the structure of these amino acids. What would this mutation do to the function of aquaporins? Design an experiment to answer this question. Consider the following methods for your experiment: It is possible to check the function of a channel protein by using artificial lipid vesicles. You can use lipid vesicles (basically a ball of a lipid bilayer with an artificial solution inside) and insert your protein of interest in the lipid bilayer of the vesicle. You can manipulate the solutions inside and outside of the artificial vesicle and check the function of the protein. Include all of the elements of experimental design in your answer. 18. A fungal cell has a potential of -180 mV (negative inside). There is more Ca2+ outside the cell than inside the cell. What can we conclude about the movement of Ca2+ in this case? a. Ca2+ will enter the cell through open channels via passive transport. b. Ca2+ will exit the cell through open channels via passive transport. c. Ca2+ will enter the cell only through active transport. d. Ca2+ will exit the cell passively through a carrier protein. e. We need more information. 19. Select all that apply: The proton pump in plant cells a. is

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