Biology HELP! Which of the following makes up the nonpolar region of biological membranes?, etc.?

1. (Points: 1)


Which of the following makes up the nonpolar region of biological membranes?


a. two fatty acids tails





b. A phosphate group and two fatty acid tails.





c. two hydrophilic tails attached to a glycerol molecule.





d. a triglyceride attached to a phosphate group





e. none of the above








2. (Points: 1)


Which statement is NOT true?


a. The lipid bilayer serves as a hydrophobic barrier between two fluid regions.





b. Membranes are often perforated by proteins that extend through both sides of the membrane.





c. The current concept of a membrane can be best summarized by the fluid mosaic model.





d. Some membranes have proteins with channels or pores that allow for the passage of hydrophilic substances.





e. Hydrophilic substances have an easier time passing through membranes than hydrophobic substances do.








3. (Points: 1)


An experiment that fused a mouse cell containing labeled plasma membrane proteins with a human cell containing labeled proteins revealed that ___________








a. Mouse proteins and human proteins are identical in their chemical composition.





b. Membrane proteins can move freely within the lipid bilayer of the plasma membrane.





c. Fused cells from two different species die because the lipid bilayers are completely incompatible.





d. The composition of the membrane is static and is responsible for its relative impermeability.





e. Only human proteins have carbohydrate groups.





4. (Points: 1)


Which of the following molecules is least likely to cross a cellular membrane by simple diffusion?











a. carbon dioxide





b. nitrogen





c. oxygen





d. potassium ion





e. B %26amp; C








5. (Points: 1)


The proteins responsible for distinguishing cell type are which of the following?











a. cell adhesion proteins





b. cell surface membrane proteins





c. peripheral anchoring proteins





d. enzymes





e. membrane transport proteins








6. (Points: 1)


Which of the following does not require the expenditure of energy by the cell











a. Active transport





b. Endocytosis





c. Osmosis





d. Facilitated diffusion





e. C %26amp; D








7. (Points: 1)


Select the true statement concerning active transport.











a. Active transport depends on membrane proteins that act as carrier proteins.





b. Active transport uses a glucose concentration gradient to move other substances across the plasma membrane.





c. Active transport depends on cholesterol molecules embedded in the plasma membrane.





d. Glycolipids are important components of the membrane transport system since they recognize the appropriate material to be transported.





8. (Points: 1)


You are interested in studying the intracellular proteins of red blood cells. An easy way to lyse the cells and gain access to these proteins would be to place the cells in an ____________ solution.











a. isotonic





b. B or C





c. hypotonic





d. osmotic





e. hypertonic








9. (Points: 1)


A single-celled freshwater organism, such as a protistan, is transferred to a hypertonic salt solution. Which of the following is likely to happen?











a. The cell bursts.





b. all of these





c. Salt is pumped out of the cell.





d. Enzymes flow out of the cell.





e. The cell shrinks.














Thank you kindly!|||I don't agree with all of the answers given above.





Hypo/hypertonic are reversed in the suggested answers form 8 and 9. 8 should be C and 9 should be E. If you don't believe me, check out the illustration about halfway down this page:


http://io.uwinnipeg.ca/~simmons/cm1503/m鈥?/a>





The answer to question 3 is B. See page 643 of this book for a description of that experiment:


http://books.google.com/books?id=iepqmRf鈥?/a>|||1. a


2. e


3. ?


4. d


5. b


6. e


7. a


8. e


9. a