4 Written questions
4 Matching questions
- 26) Nitrous oxide gas molecules diffusing across a cell's plasma membrane is an example of
A) diffusion across the lipid bilayer.
B) facilitated diffusion.
C) active transport.
- 23) Why are lipids and proteins free to move laterally in membranes?
A) The interior of the membrane is filled with liquid water.
B) Lipids and proteins repulse each other in the membrane.
C) Hydrophilic portions of the lipids are in the interior of the membrane.
D) There are only weak hydrophobic interactions in the interior of the membrane.
E) Molecules such as cellulose can pull them in various directions.
- 74) A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water-equal to the volume of blood lost-is transferred directly into one of his veins. What will be the most probable result of this transfusion?
A) It will have no unfavorable effect as long as the water is free of viruses and bacteria.
B) The patient's red blood cells will shrivel up because the blood fluid has become hypotonic compared to the cells.
C) The patient's red blood cells will swell because the blood fluid has become hypotonic compared to the cells.
D) The patient's red blood cells will shrivel up because the blood fluid has become hypertonic compared to the cells.
E) The patient's red blood cells will burst because the blood fluid has become hypertonic compared to the cells.
- 24) What kinds of molecules pass through a cell membrane most easily?
A) large and hydrophobic
B) small and hydrophobic
C) large polar
E) monosaccharides such as glucose
- a d
- b b
- c a
- d c
5 Multiple choice questions
5 True/False questions
9) In order for a protein to be an integral membrane protein it would have to be
C) amphipathic, with at least one hydrophobic region.
D) completely covered with phospholipids.
E) exposed on only one surface of the membrane. → e
35) Which of the following membrane activities require energy from ATP hydrolysis?
A) facilitated diffusion of chloride ions across the membrane through a chloride channel
B) movement of water into a cell
C) Na+ ions moving out of a mammalian cell bathed in physiological saline
D) movement of glucose molecules into a bacterial cell from a medium containing a higher concentration of glucose than inside the cell
E) movement of carbon dioxide out of a paramecium → c
34) When a plant cell, such as one from a peony stem, is submerged in a very hypotonic solution, what is likely to occur?
A) The cell will burst.
B) The cell membrane will lyse.
C) Plasmolysis will shrink the interior.
D) The cell will become flaccid.
E) The cell will become turgid. → a
29) Water passes quickly through cell membranes because
A) the bilayer is hydrophilic.
B) it moves through hydrophobic channels.
C) water movement is tied to ATP hydrolysis.
D) it is a small, polar, charged molecule.
E) it moves through aquaporins in the membrane. → c
41) Which of the following is most likely true of a protein that cotransports glucose and sodium ions into the intestinal cells of an animal?
A) The sodium ions are moving down their electrochemical gradient while glucose is moving up.
B) Glucose entering the cell along its concentration gradient provides energy for uptake of sodium ions against the electrochemical gradient.
C) Sodium ions can move down their electrochemical gradient through the cotransporter whether or not glucose is present outside the cell.
D) The cotransporter can also transport potassium ions.
E) A substance that blocks sodium ions from binding to the cotransport protein will also block the transport of glucose. → e