AP Bio Chapter 7

43) Which line represents the bag with the highest initial concentration of sucrose?

A)

7) fiber of the extra cellular matrix

A)

30) Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly? A) CO2 B) an amino acid C) glucose D) K+ E) starch

A) CO2

2) Membranes are a phospholipid bilater between two layers of hydrophilic proteins. A. H. Davson and J. Danielli B. I. Langmuir C. C. Overton D. S. Singer and G. Nicolson E. E. Gorter and F. Grendel

A) H. Davson and J. Danielli

61) The sodium-potassium pump in animal cells requires cytoplasmic ATP to pump ions across the plasma membrane. When the proteins of the pump are first synthesized in the rough ER, what side of the ER membrane will the ATP binding site be on? A) It will be on the cytoplasmic side of the ER. B) It will be on the side facing the interior of the ER. C) It could be facing in either direction because the orientation of proteins is scrambled in the Golgi apparatus. D) It doesn't matter, because the pump is not active in the ER. E) Not enough information is provided to answer this question.

A) It will be on the cytoplasmic side of the ER.

26) Which of the following adheres to the extracellular surface of animal cell plasma membranes? A) fibers of the extracellular matrix B) fibers of the cytoskeleton C) the phospholipid bilayer D) cholesterol E) carrier proteins

A) fibers of the extracellular matrix

38) A cell whose cytoplasm has a concentration of 0.02 molar glucose is placed in a test tube of water containing 0.02 molar glucose. Assuming that glucose is not actively transported into the cell, which of the following terms describes the tonicity of the external solution relative to the cytoplasm of the cell? A) isotonic B) hypertonic C) hypotonic D) flaccid E) turgid

A) isotonic

19) All of the following are functions of integral membrane proteins except A) protein synthesis. B) active transport. C) hormone reception. D) cell adhesion. E) cytoskeleton attachment.

A) protein synthesis.

9) glycolipid

B)

44) Which line or lines represent(s) bags that contain a solution that is hypertonic at the end of 60 minutes? A) A and B B) B C) C D) D E) D and E

B) B

28) Which of the following is a characteristic feature of a carrier protein in a plasma membrane? A) It is a peripheral membrane protein. B) It exhibits a specificity for a particular type of molecule. C) It requires the expenditure of cellular energy to function. D) It works against diffusion. E) It has few, if any, hydrophobic amino acids.

B) It exhibits a specificity for a particular type of molecule.

49) The movement of a substance across a biological membrane against its concentration gradient with the help of energy input is A) diffusion. B) active transport. C) osmosis. D) facilitated diffusion. E) exocytosis

B) active transport.

25) An animal cell lacking oligosaccharides on the external surface of its plasma membrane would likely be impaired in which function? A) transporting ions against an electrochemical gradient B) cell-cell recognition C) maintaining fluidity of the phospholipid bilayer D) attaching to the cytoskeleton E) establishing the diffusion barrier to charged molecules

B) cell-cell recognition

11) all of the following molecules are part of the cell membrane except: A) lipids B) nucleic acids C) phosphate groups D) proteins E) steroids

B) nucleic acids

8) microfilament of the cytoskeleton

C)

use situation 7.4 (http://www.easynotecards.com/uploads/1152/0/1c7a7974_150bb922c9b__8000_00002352.png) 42) Which line represents the bag that contained a solution isotonic to the 0.6 molar solution at the beginning of the experiment?

C)

17) The surface of an integral membrane protein would be best described as A) hydrophilic. B) hydrophobic. C) amphipathic. D) completely covered with phospholipids. E) exposed on only one surface of the membrane.

C) amphipathic.

63) All of the following processes take material into cells except A) pinocytosis. B) endocytosis. C) exocytosis. D) active transport. E) carrier-facilitated diffusion.

C) exocytosis.

3) The membrane is a mosaic of protein molecules bobbing in a fluid bilayer of phospholipids A. H. Davson and J. Danielli B. I. Langmuir C. C. Overton D. S. Singer and G. Nicolson E. E. Gorter and F. Grendel

D) S. Singer and G. Nicolson

6) Cholesterol

E)

60) What mechanisms do plants use to load sucrose produced by photosynthesis into specialized cells in the veins of leaves? A) an electrogenic pump B) a proton pump C) a contra sport protein D) A and C only E) A, B, and C

E) A, B, and C

20) Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures? A) The double bonds form a kink in the fatty acid tail, forcing adjacent lipids to be further apart. B) Unsaturated fatty acids have a higher cholesterol content. C) Unsaturated fatty acids permit more water in the interior of the membrane. D) The double bonds block interaction among the hydrophilic head groups of the lipids. E) The double bonds result in a shorter fatty acid tail.

A) The double bonds form a kink in the fatty acid tail, forcing adjacent lipids to be further apart.

16) What is one of the ways that the membranes of winter wheat are able to remain fluid when it is extremely cold? A) by increasing the percentage of unsaturated phospholipids in the membrane B) by increasing the percentage of cholesterol molecules in the membrane C) by decreasing the number of hydrophobic proteins in the membrane D) A and B only E) A, B, and C

A) by increasing the percentage of unsaturated phospholipids in the membrane

54) In most cells, there are electrochemical gradients of many ions across the plasma membrane even though there are usually only one or two electrogenic pumps present in the membrane. The gradients of the other ions are most likely accounted for by A) co transport proteins. B) ion channels. C) carrier proteins. D) B and C only E) A, B, and C

A) co transport proteins.

67) What is the cause of familial hypercholesterolemia? A) defective LDL receptors on the cell membranes B) poor attachment of the cholesterol to the extracellular matrix of cells C) a poorly formed lipid bilayer that cannot incorporate cholesterol into cell membranes D) inhibition of the cholesterol active transport system in red blood cells E) a general lack of glycolipids in the blood cell membranes

A) defective LDL receptors on the cell membranes

13) the presence of cholesterol in the plasma membranes of some animals A) enables the membrane to stay fluid more easily when cell temperature drops B) enables the animal to remove hydrogen atoms from saturated phospholipids C) enables the animal to add hydrogen atoms to unsaturated phospholipids D) makes the membrane less flexible, allowing it to sustain greater pressure from within the cell E) make the animal more susceptible to circulatory disorders

A) enables the membrane to stay fluid more easily when cell temperature drops

47) All of the following membrane activities require energy from ATP hydrolysis except A) facilitated diffusion. B) active transport. C) Na+ ions moving out of the cell. D) proton pumps. E) translocation of potassium into a cell.

A) facilitated diffusion.

69) The difference between pinocytosis and receptor-mediated endocytosis is that A) pinocytosis brings only water into the cell, but receptor-mediated endocytosis brings in other molecules as well. B) pinocytosis increases the surface area of the plasma membrane whereas receptor-mediated endocytosis decreases the plasma membrane surface area. C) pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity. D) pinocytosis requires cellular energy, but receptor-mediated endocytosis does not. E) pinocytosis can concentrate substances from the extracellular fluid, but receptor-mediated endocytosis cannot.

A) pinocytosis brings only water into the cell, but receptor-mediated endocytosis brings in other molecules as well.

68) In addition to exporting materials from the cytoplasm of the cell, the process of exocytosis is also important in A) the production of cell walls by plant cells. B) the increase in the size of cells. C) maintaining the osmotic balance between the cytoplasm and the cell exterior. D) A and B only E) A, B, and C

A) the production of cell walls by plant cells.

53) What is the voltage across a membrane called? A) water potential B) chemical gradient C) membrane potential D) osmotic potential E) electrochemical gradient

C) membrane potential

14) according to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids? A) they can move laterally along the plane of the membrane B) They frequently flip-flop from one side of the membrane to the other. C) They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane. D) They are free to depart from the membrane and dissolve in the surrounding solution. E) They have hydrophilic tails in the interior of the membrane.

A) they can move laterally along the plane of the membrane

66) White blood cells engulf bacteria through what process? A) exocytosis B) phagocytosis C) pinocytosis D) osmosis E) receptor-mediated exocytosis

B) phagocytosis

use situation 7.3 (http://d2vlcm61l7u1fs.cloudfront.net/media%2Fec9%2Fec9240a2-063a-4e48-858b-1ab074517422%2FphppKjb9B.png) 39) At the beginning of the experiment, A) side A is hypertonic to side B. B) side A is hypotonic to side B. C) side A is isotonic to side B. D) side A is hypertonic to side B with respect to glucose. E) side A is hypotonic to side B with respect to sodium chloride

B) side A is hypotonic to side B.

27) What kinds of molecules pass through a cell membrane most easily? A) large and hydrophobic B) small and hydrophobic C) large polar D) ionic E) monosaccharides such as glucose

B) small and hydrophobic

4) which of the following types of molecules are the major structural components of the cell membrane? A) phospholipids and cellulose B) nucleic acids and proteins C) proteins and phospholipids D) proteins and cellulose E) glycoproteins and cholesterol

C) proteins and phospholipids

32) Which of the following statements is correct about diffusion? A) It is very rapid over long distances. B) It requires an expenditure of energy by the cell. C) It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration. D) It is an active process in which molecules move from a region of lower concentration to one of higher concentration. E) It requires integral proteins in the cell membrane.

C) It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration

56) If a membrane protein in an animal cell is involved in the co transport of glucose and sodium ions into the cell, which of the following is most likely not true? A) The sodium ions are moving down their electrochemical gradient. B) Glucose is entering the cell against its concentration gradient. C) Sodium ions can move down their electrochemical gradient through the co transporter whether or not glucose is present outside the cell. D) The higher sodium ion concentration outside the cell is the result of an electrogenic pump. E) A substance that blocked sodium ions from binding to the co transport protein would also block the transport of glucose.

C) Sodium ions can move down their electrochemical gradient through the co transporter whether or not glucose is present outside the cell.

36) 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 is hypotonic compared to the cells. C) The patient's red blood cells will swell because the blood fluid is hypotonic compared to the cells. D) The patient's red blood cells will shrivel up because the blood fluid is hypertonic compared to the cells. E) The patient's red blood cells will burst because the blood fluid is hypertonic compared to the cells

C) The patient's red blood cells will swell because the blood fluid is hypotonic compared to the cells.

62) Which of the following statements about membrane structure and function is false? A) Diffusion of gases is faster in air than across membranes. B) Diffusion, osmosis, and facilitated diffusion do not require any direct energy input from the cell. C) The types of proteins that are exposed on one side of a membrane are nearly identical to those exposed on the other side of the membrane. D) Voltage across the membrane depends on an unequal distribution of ions across the plasma membrane. E) Special membrane proteins can co transport two solutes by coupling diffusion down a concentration gradient to transport against the concentration gradient.

C) The types of proteins that are exposed on one side of a membrane are nearly identical to those exposed on the other side of the membrane

35) After the system reaches equilibrium, what changes are observed? A) The molarity of sucrose and glucose are equal on both sides. B) The molarity of glucose is higher in side A than in side B. C) The water level is higher in side A than in side B. D) The water level is unchanged. E) The water level is higher in side B than in side A.

C) The water level is higher in side A than in side B.

21) Which of the following is correct about integral membrane proteins? A) They lack tertiary structure. B) They are loosely bound to the surface of the bilayer. C) They are usually transmembrane proteins. D) They are not mobile within the bilayer. E) They serve only a structural role in membranes.

C) They are usually transmembrane proteins.

50) Carrier molecules in the membrane and metabolic energy are required for A) osmosis. B) facilitated diffusion. C) active transport. D) B and C only E) A, B, and C

C) active transport.

57) The movement of potassium into an animal cell requires A) low cellular concentrations of sodium. B) high cellular concentrations of potassium. C) an energy source such as ATP or a proton gradient. D) a co transport protein. E) a gradient of protons across the plasma membrane.

C) an energy source such as ATP or a proton gradient.

55) The sodium-potassium pump is called an electrogenic pump because it A) pumps equal quantities of Na+ and K+ across the membrane. B) pumps hydrogen ions out of the cell. C) contributes to the membrane potential. D) ionizes sodium and potassium atoms. E) is used to drive the transport of other molecules against a concentration gradient.

C) contributes to the membrane potential.

37) Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a salt solution become limp and soft. From this we can deduce that the cells of the celery stalks are A) hypotonic to both fresh water and the salt solution. B) hypertonic to both fresh water and the salt solution. C) hypertonic to fresh water but hypotonic to the salt solution. D) hypotonic to fresh water but hypertonic to the salt solution. E) isotonic with fresh water but hypotonic to the salt solution.

C) hypertonic to fresh water but hypotonic to the salt solution.

use situation 7.2 (http://www.easynotecards.com/uploads/1147/94/1c7a7974_150bb922c9b__8000_00002292.png) 34) Initially, in terms of tonicity, the solution in side A with respect to that in side B is A) hypotonic. B) plasmolyzed. C) isotonic. D) saturated. E) hypertonic.

C) isotonic.

23) What is one of the functions of cholesterol in animal cell membranes? A) facilitates transport of ions B) stores energy C) maintains membrane fluidity D) speeds diffusion E) phosphorylates ADP

C) maintains membrane fluidity C) maintains membrane fluidity

For 5-9 use (https://goo.gl/images/TnKMuX): 5) peripheral protein

D)

15) The lateral mobility (fluidity) of lipids and proteins in membranes is a consequence of A) lack of covalent bonds between the lipid and protein components of the membrane. B) weak hydrophobic interactions among the components in the interior of the membrane. C) the presence of liquid water in the interior of the membrane. D) A and B only E) A, B, and C

D) A and B only

31) The selective permeability of biological membranes is dependent on which of the following? A) the type of transport proteins that are present in the membrane B) the lipid bilayer being permeable to primarily small, nonpolar molecules C) the types of carbohydrates on the surface of the membrane D) A and B only E) A, B, and C

D) A and B only

45) What is (are) the best explanation(s) for the shape of line E after 50 minutes? A) The bag is isotonic with the solution around it. B) Water is entering and leaving the bag at the same rate. C) Sucrose is entering and leaving the bag at the same rate. D) A and B only E) A, B, and C

D) A and B only

41) Which of the following statements correctly describes the normal tonicity conditions for typical plant and animal cells? A) The animal cell is in a hypotonic solution, and the plant cell is in an isotonic solution. B) The animal cell is in an isotonic solution, and the plant cell is in a hypertonic solution. C) The animal cell is in a hypertonic solution, and the plant cell is in an isotonic solution. D) The animal cell is in an isotonic solution, and the plant cell is in a hypotonic solution. E) The animal cell is in a hypertonic solution, and the plant cell is in a hypotonic solution

D) The animal cell is in an isotonic solution, and the plant cell is in a hypotonic solution.

40) If you examine side A after 3 days, you should find A) a decrease in the concentration of NaCl and glucose and an increase in the water level. B) a decrease in the concentration of NaCl, an increase in water level, and no change in the concentration of glucose. C) no net change in the system. D) a decrease in the concentration of NaCl and a decrease in the water level. E) no change in the concentration of NaCl and glucose and an increase in the water level.

D) a decrease in the concentration of NaCl and a decrease in the water level.

58) Ions diffuse across membranes down their A) chemical gradients. B) concentration gradients. C) electrical gradients. D) electrochemical gradients. E) A and B are correct.

D) electrochemical gradients.

18) When a membrane is freeze-fractured, the bilayer splits down the middle between the two layers of phospholipids. In an electron micrograph of a freeze-fractured membrane, the bumps seen on the fractured surface of the membrane are A) peripheral proteins. B) phospholipids. C) carbohydrates. D) integral proteins. E) cholesterol molecules.

D) integral proteins.

64) An organism with a cell wall would have the most difficulty doing which process? A) diffusion B) osmosis C) active transport D) phagocytosis E) exocytosis

D) phagocytosis

65) The membrane activity most nearly opposite to exocytosis is A) plasmolysis. B) osmosis. C) facilitated diffusion. D) phagocytosis. E) active transport

D) phagocytosis.

29) After a membrane freezes and then thaws, it often becomes leaky to solutes. The most reasonable explanation for this is that A) transport proteins become nonfunctional during freezing. B) the lipid bilayer loses its fluidity when it freezes. C) aquaporins can no longer function after freezing. D) the integrity of the lipid bilayer is broken when the membrane freezes. E) the solubility of most solutes in the cytoplasm decreases on freezing.

D) the integrity of the lipid bilayer is broken when the membrane freezes.

12) the original model for the bilayer structure of cell membranes, which was prepared in the 1920s, was based on which of the following? A) detailed electron micrograph a of freeze-fractured membranes B) the presence of proteins as a functional component of biological membranes C) the observation that all membranes contain phospholipids and proteins D) the understanding that phospholipids are amphipathic molecules E) A and B only

D) the understanding that phospholipids are amphipathic molecules

52) The main difference(s) between facilitated diffusion and active transport is (are) A) facilitated diffusion moves substances down their concentration gradient and active transport moves them against their gradient. B) facilitated diffusion does not rely on cellular energy and active transport does. C) facilitated diffusion uses channel or carrier proteins and active transport does not. D) A and B only E) A, B, and C

E) A, B, and C

59) Which of the following characterizes the sodium-potassium pump? A) Sodium ions are pumped out of a cell against their gradient. B) Potassium ions are pumped into a cell against their gradient. C) The pump protein undergoes a conformational change. D) Only A and B are correct. E) A, B, and C are all correct.

E) A, B, and C are all correct.

1) The first to propose that cell membranes are phospholipid bilayers A. H. Davson and J. Danielli B. I. Langmuir C. C. Overton D. S. Singer and G. Nicolson E. E. Gorter and F. Grendel

E) E. Gorter and F. Grendel

22) Of the following functions, which is most important for the glycoproteins and glycolipids of animal cell membranes? A) facilitated diffusion of molecules down their concentration gradients B) active transport of molecules against their concentration gradients C) maintaining the integrity of a fluid mosaic membrane D) maintaining membrane fluidity at low temperatures E) a cell's ability to distinguish one type of neighboring cell from another

E) a cell's ability to distinguish one type of neighboring cell from another

51) Glucose diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose-rich food into their glucose-poor cytoplasm. Using this information, which transport mechanism is most probably functioning in the intestinal cells? A) simple diffusion B) phagocytosis C) active transport pumps D) exocytosis E) facilitated diffusion

E) facilitated diffusion

24) What membrane-surface molecules are thought to be most important as cells recognize each other? A) phospholipids B) integral proteins C) peripheral proteins D) cholesterol E) glycoproteins

E) glycoproteins

48) What are the membrane structures that function in active transport? A) peripheral proteins B) carbohydrates C) cholesterol D) cytoskeleton filaments E) integral proteins

E) integral proteins

33) 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.

E) it moves through aquaporins in the membrane.

46) You are working on a team that is designing a new drug. In order for this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would not be a factor that determines whether the molecule enters the cell? A) size of the drug molecule B) polarity of the drug molecule C) charge on the drug molecule D) similarity of the drug molecule to other molecules transported by the target cells E) lipid composition of the target cells' plasma membrane

E) lipid composition of the target cells' plasma membrane

10) when biological membranes are frozen and then fractured, they tend to break along the middle of the bilayer. The best explanation for this is that: A) the integral membrane proteins are not strong enough to hold the bilayer together B) water that is present in the middle of the bilayer freezes and is easily fractured C) hydrophilic interactions between the opposite membrane surfaces are destroyed on freezing D) the carbon-carbon bonds of the phospholipid tails are easily broken E) the hydrophobic interaction that hold the membrane together are weakest at this point

E) the hydrophobia interactions that hold the membrane together are weakest at this point