CHAPTER 5, MEMBRANE STRUCTURE AND FUNCTION QUIZ

CIRCLE THE CORRECT ANSWER

1. The major functions of the plasma membrane do Not include

    separation of the fluid environments inside and outside the cell.

    regulation of molecules and ions that pass into and out of the cell.

    recognition and communication between different cells and tissues.

    maintaining connections between adjacent cells

    production of proteins used in construction of the cell wall.

2. When plant cells are exposed to a hypertonic solution they ____ and exhibit the
phenomenon called _____.

    expand, plasmolysis

    shrink, plasmolysis

    expand, turgor pressure

    shrink, turgor pressure

    remain the same, crenation

3. The current theory of the structure of the plasma membrane is best described by the _______ model.

    sandwich

    fluid-mosaic

    unit membrane

    electrochemical

    unipermeable

4. In a phospholipid bilayer, the

    phosphate groups are hydrophobic.

    fatty acids tails are ionized.

    fatty acid tails are hydrophilic

    proteins are located only between the two layers.

    phosphate heads are oriented toward the exterior of the cell or toward the cytoplasm.

5. Which statement is True about the plasma membrane?

    The proteins make up the matrix of the membrane.

    The model can be likened to a sandwich where phospholipids are like the bread and proteins are like the filling.

    The fluid nature of the membrane is regulated by flip-flopping of the phospholipids from one side of the
    membrane to the other.

    Movement of proteins and phospholipids can occur sideways within the plane of the membrane.

6. Which statement is Not true about the proteins in the plasma membrane?

    Proteins may be attached to the inner surface of the plasma membrane.

    The hydrophobic portion of a protein is embedded within the membrane.

    Some plasma proteins are connected to cytoskeletal filaments.

    Plasma proteins are responsible for membrane functions.

    Glycoproteins contain carbohydrate chains that are oriented toward the inner surface of the membrane.

7. Which phrase does Not describe one of the functions of proteins of the plasma membrane?

    forming a channel through the membrane

    initiating the replication of the genetic material

    binding to a substance to carry it through the membrane

    acting as a receptor for substances external to the cell

    increasing the rate of a chemical reaction

8. Red blood cells come in many "blood types" including type A , type B, type AB, Type O, Rh positive and
Rh negative and many others. If blood is transfused, the recipient detects and new or "foreign" proteins.
These blood type proteins are

    in the plasma where they have been secreted by the red blood cells.

    inside the red blood cell cytoplasm.

    on the outer surface of the red blood cell membrane.

    evenly distributed throughout the cell contents and plasma.

    in the red blood cell nucleus.

9. Whether a molecule can cross the plasma membrane depends upon

    the size of the molecule

    the shape of the molecule

    the chemical properties of the molecule

    the charge of the molecule

    all of the above

10. Which is the Best definition of diffusion?

    movement of molecules from an area of their higher concentration to an area of their lower concentration

    movement of water across a semipermeable membrane from an area of high water concentration to an area
    of lower water concentration.

    movement of molecules from an area of their lower concentration to and area of their higher concentration.

    movement of water across a semipermeable membrane from an area of low water concentration to an area
    of higher water concentration.

    movement of a substance against its concentration through the release of energy from ATP.

11. Which is the Best definition of osmosis?

    movement of molecules from an area of their higher concentration to an area of their lower concentration

    movement of water across a semipermeable membrane from an area of high water concentration to an area
    of lower water concentration.

    movement of molecules from an area of their lower concentration to and area of their higher concentration.

    movement of water across a semipermeable membrane from an area of low water concentration to an area
    of higher water concentration.

    movement of a substance against its concentration through the release of energy from ATP.

12. Plants show turgor pressure when

    cells are losing water from their water vacuoles.

    cells contain water vacuoles that are full of water.

    water is being used up in photosynthesis.

    water is being evaporated from the leaves.

13. If a cell is placed in a hypotonic solution, which will occur?

    Salts will move into the cell from the surrounding solution.

    Water will move into the cell from the surrounding solution.

    Salts will move out of the cell into the surrounding solution.

    Water will move out of the cell into the surrounding solution.

    None of the above will occur.

14. If a cell is placed in a hypertonic solution, which will occur?

    Salts will move into the cell from the surrounding solution.

    Water will move into the cell from the surrounding solution.

    Salts will move out of the cell into the surrounding solution.

    Water will move out of the cell into the surrounding solution.

    None of the above will occur.

15. If a cell is placed in an isotonic solution, which will occur?

    Salts will move into the cell from the surrounding solution.

    Water will move into the cell from the surrounding solution.

    Salts will move out of the cell into the surrounding solution.

    Water will move out of the cell into the surrounding solution.

    None of the above will occur.

16. Freshwater protozoans react to a/an _______ environment by removing water through _____.

    hypertonic, turgor pressure

    hypotonic, turgor pressure

    isotonic, a contractile vacuole

    hypertonic, a contractile vacuole

    hypotonic, a contractile vacuole

17. ______ is a shrinking of the cytoplasm due to osmosis.

    Plasmolysis

    Endocytosis

    Crenation

    Diffusion

    Turgor

18. Which is the Best definition of active transport?

    movement of molecules from an area of their higher concentration to an area of their lower concentration

    movement of water across a semipermeable membrane from an area of high water concentration to an area
    of lower water concentration.

    movement of molecules from an area of their lower concentration to and area of their higher concentration.

    movement of water across a semipermeable membrane from an area of low water concentration to an area
    of higher water concentration.

    movement of a substance against its concentration through the release of energy from ATP.

19. The sodium-potassium pump moves sodium and potassium ions across the plasma membrane by

    facilitated transport

    active transport

    cotransport

    endocytosis

    exocytosis

20. Sugar and amino acids are carried into the cell by membrane proteins by means of

    facilitated transport

    active transport

    simple diffusion

    endocytosis

    exocytosis

21. The process by which cholesterol is transported into the cell by binding of LDL, to its receptor and the
internalization of the receptor-LDL complex is

    facilitated transport

    active transport

    cotransport

    endocytosis

    exocytosis

22. Which term is derived from the Greek root word meaning "out of cell"?

    osmosis

    endocytosis

    tonicity

    diffusion

    exocytosis

23. Cell products are secreted from the cell through

    facilitated transport

    active transport

    cotransport

    endocytosis

    exocytosis

24. Pinocytosis is an example of

    facilitated transport

    active transport

    cotransport

    endocytosis

    exocytosis

25. Which is Not true about plant cell walls?

    All plant cells have a primary cell wall.

    Primary cell walls contain cellulose and hemicellulose.

    Secondary cell walls are located just outside the primary cell wall.

    Secondary cell walls occur only in woody plants.

    Cell walls are penetrated by extensions of cytoplasm that connect adjacent cells' cytoplasm.

26. Eukaryotic cells are substantially larger than bacteria cells and average over 20 times more volume per
surface area than bacteria cells. How can the eukaryotic cell membrane provide this higher rate of exchange
of materials?

    Plasma membrane folds increase the surface area.

    Carrier proteins speed the rate at which a solute crosses the plasma membrane in the direction of
    decreasing concentration.

    Mitochondria are concentrated near membranes to provide energy for active transport of molecules or ions.

    Large molecules are engulfed by vesicle formation.

    All of the above are true.

27. A phospholipid molecule has a head and two tails. The tails are found

    at the surface of the membrane

    in the interior of the membrane

    spanning the membrane

    where the environment is hydrophilic

    Both a and b are correct.

28. During diffusion

    solvents move from the area of higher to lower concentration but not the solutes.

    there is a net movement of molecules from an area of higher to lower concentration.

    a cell must be present for any movement of molecules to occur.

    molecules move against their concentration gradient if they are small or charged.

    All of these are correct.

29. Active transport

    requires a carrier protein.

    moves a molecule against its concentration gradient.

    requires a supply of chemical energy.

    does not occur during facilitated transport.

    All of these are correct.

30. The sodium potassium pump

    helps establish an electrochemical gradient across the membrane.

    concentrates sodium on the outside of the membrane.

    utilizes a carrier protein and chemical energy.

    is present in the plasma membrane

    All of these are correct.

31. The barrier between the interior of a human cell and its external environment is known as the cell wall.
    True     False

32. Lipid-soluble molecules are able to diffuse into a cell more rapidly than water-soluble molecules.
    True     False

33. The modern model of the plasma membrane structure was first described in 1986.
    True     False

34. Fluidity of a membrane increases as the percentage of unsaturated fatty acids in the phospholipids goes up.
    True     False

35. The lipid portion of a plasma membrane acts like a liquid at the temperature of the human body.
    True     False

36. All cells contain the same kinds of proteins in the same relative locations.
    True     False

37. Crenation of red blood cells results when red blood cells lose water into a fluid environment
that contains more solutes than the cell.
    True     False

38. Cells placed in an isotonic environment will die as they swell and burst.
    True     False

39. Carrier proteins are necessary for active transport to occur.
    True     False

40. In the sodium-potassium pump, sodium is transported out of the cell and potassium is
transported into the cell as ATP is broken by a membrane protein.
    True     False

41. The process by which a white blood cell or an amoeba engulfs bacteria is called phagocytosis.
    True     False

42. Receptors are involved in the movement of some materials across the plasma membrane.
    True     False

43. An extracellular matrix helps some cells to adhere to neighboring cells.
    True     False

44. In the cells that line the lumen of the small intestine, gap junctions keep materials from
the digestive tract from slipping between the cells and entering the tissue.
    True     False

45. Which of the following forms of cell transport requires the input of energy?

    diffusion

    osmosis

    facilitated diffusion

    movement of a solute down its concentrated gradient

    active transport

46. Among the following choices, which one would most readily move through a
selectively permeable membrane?

    small uncharged polar molecules

    protein hormone

    large uncharged polar molecules

    glucose

    sodium ion

47. Which of the following requires the input of energy?

    osmosis

    facilitated diffusion

    diffusion

    sodium potassium pump

    movement of water down its concentration gradient

48. A cell is placed into a hypertonic environment and its cytoplasm shrivels up.
This demonstrates the principle of

    photolysis

    diffusion

    active transport

    facilitated diffusion

    plasmolysis

49. Which structures are important to the permeability of a cell membrane?

    microfilaments

    cell walls

    ribosomes

    monosaccharides

    integral proteins

50. Which of the following substances is most likely to pass through a selectively permeable plasma membrane?

    O2

    K+

    glucose

    NH3

    starch

51. All of the following processes transport mechanisms into a cell Except

    phagocytosis

    contractile vacuoles

    porin channels

    receptor mediated endocytosis

    pinocytosis

52. Sodium and potassium pass through the neural membrane by

    movement through channels

    endocytosis

    diffusion

    passive transport

    phagocytosis

53. ATP is required for all of the following processes Except

    active transport by transport proteins

    facilitated diffusion

    microtubule movement within flagella

    Na+/K+ pump activity

    protein synthesis

54. All of the following can be found in plasma membranes of eukaryotes Except

    cellulose

    phospholipids

    oligosaccharides

    proteins

    cholesterol molecules

55. All of the following are typical components of the plasma membrane of a eukaryotic cell Except

    glycoproteins

    cytochromes

    cholesterol

    phospholipids

    integral proteins

56. Which of the following cellular process is coupled with the hydrolysis of ATP

    facilitated diffusion

    active transport

    chemiosmosis

    osmosis

    Na+ influx into a nerve cell

57. Facilitated diffusion

    is a type of passive transport

    moves molecules down the concentration gradient

    is made possible by specific molecules within the membrane

    requires no expenditure of energy

    All of the above apply.

58. Which of the following molecules or ions move across membranes by active transport?

    glucose

    Na (sodium)

    water

    ATP

    starch

59. The movement of water across a selectively permeable membrane in response to a
concentration gradient exerts a force which is called

    force of diffusion

    hypertonic

    plasmogamy

    osmotic pressure

    cytotaxis

60.  The difference between osmotic pressure and physical pressure on either side of a

selectively permeable membrane is called

    force of diffusion

    water potential

    workload

    environmental resistance

    carrying capacity

61. The theoretical model of membrane structure proposed by Singer and Nicholson
in 1972 is called the _____ model.

    carpal tunnel

    rigid tile

    flexible sheet

    expandable bubble

    fluid mosaic

62. When plant cells are exposed to a hypotonic solution they ____ and exhibit the
phenomenon called _____.

    expand, plasmolysis

    shrink, plasmolysis

    expand, turgor pressure

    shrink, turgor pressure

    remain the same, crenation