Chapter Quiz
1.  

Which of the following best describes the general structure of a cell membrane? (p. 139)

proteins sandwiched between two layers of phospholipid
proteins embedded in two layers of phospholipid
a layer of protein coating a layer of phospholipid
phospholipids sandwiched between two layers of protein
phospholipids embedded in two layers of protein


2.  

Which of the following functional processes results from the presence of protein within the plasma membrane? (p. 144)

enzymatic activity
cell-cell recognition
intercellular joining
cell-cell communication
all of the above


3.  

Select the correct statement concerning membrane carbohydrates. (p. 143)

Carbohydrates are only found associated with the membranes of prokaryotic cells.
Glucose is the most abundant membrane carbohydrate.
Cell membranes consist of protein and phospholipid; carbohydrate is not a membrane component.
Membrane carbohydrates function primarily in cell-cell recognition.
When combined with a protein, they form a glycolipid.


4.  

One consequence of the sidedness of the plasma membrane is that _____. (p. 143)

molecules that begin on the outside face of the endoplasmic reticulum end up on the inside face of the plasma membrane
the asymmetrical distribution of membrane proteins, lipids, and carbohydrates is determined as the membrane is being constructed
each membrane protein has directional orientation in the membrane
membrane carbohydrates are restricted to the extracellular surface of the plasma membrane
all of the above


5.  

Why are phospholipids well suited to be the main structural components of membranes? (p. 144)

They are completely insoluble in water.
They form a single sheet in water.
They form a structure in which the hydrophobic portion faces outward.
They form a selectively permeable structure.
They are triglycerides, which are commonly available in foods.


6.  

The membrane is referred to as a "fluid mosaic" structure. Which of the following statements is true? (p. 140)

The fluid is phospholipid and the mosaic is carbohydrate.
The fluid is protein and the mosaic is phospholipid.
The mosaic comprises the carbohydrate chains on the inner surface of the membrane.
The fluid is phospholipid and the mosaic is protein.
The term refers to the appearance of cells in a tissue.


7.  

Which of the following is NOT a function of membrane proteins? (p. 144)

Membrane proteins attach the membrane to the cytoskeleton.
Membrane proteins provide receptors for chemical messengers.
Membrane proteins form channels to move substances across the membrane.
Membrane proteins with short sugar chains form identification tags that are recognized by other cells.
All of these are functions of membrane proteins.


8.  

The freeze-fracture method is an especially good technique to view ____________. (p. 140)

the coded information in DNA
thin sections (slices) of fixed and embedded cells
the internal structure of membranes
patterns of movement in living cells
all of the above


9.  

Stability of the plasma membrane is enhanced by _____. (p. 141)

cholesterol molecules
saturated triglycerides
saturated phospholipids
polyunsaturated triglycerides
hydrogenation of the component lipids


10.  

All of the following are found in membranes EXCEPT _____. (p. 142)

phospholipids
glycolipids
steroids
glycoproteins
glyconucleic acids


11.  

The lipids in a cell membrane are arranged _____. (p. 139)

between two layers of protein
on either side of a single layer of protein
so that the polar parts of two lipids point toward each other
so that the nonpolar parts of two lipids point toward each other
none of the above


12.  

Phospholipids are well suited to serve as the major component of the plasma membrane because they _____. (p. 139)

have a water-soluble part and a water-insoluble part
have very diverse structures and can act as receptors, enzymes, and channel molecules
allow all needed molecules to pass through the membrane while being impermeable to any toxic substances
contain protein
all of the above


13.  

Consider the currently accepted fluid-mosaic model of the plasma membrane. Where in the membrane would cholesterol most likely be found? (p. 142)

on the outside surface
in the interior
on the inside surface
in the interior and on the inside surface, but not on the outside surface
none of the above


14.  

Consider the currently accepted fluid-mosaic model of the plasma membrane. Where in the membrane would oligosaccharides most likely be found? (p. 143)

on the outside surface
in the interior
on the inside surface
in the interior and on the inside surface, but not on the outside surface
none of the above


15.  

Which of the following statements is true about passive transport? (p. 145)

Passive transport operates independently of diffusion.
Passive transport operates independently of concentration.
Passive transport phenomena can never reach equilibrium.
Passive transport does not occur in the human body.
Passive transport requires no ATP input.


16.  

Which one of the following molecules is most likely to diffuse freely across the lipid bilayer of the cell membrane without the involvement of a transport protein? (p. 145)

carbon dioxide
glucose
sodium ion
DNA
hemoglobin


17.  

The movement of atoms, ions, or molecules from a region of higher concentration to regions of lower concentration is called _____. (p. 144)

spontaneous combustion
diffusion
heat
crenation
active transport


18.  

Materials that readily cross the lipid portion of a cell membrane are typically _____. (p. 144)

nonpolar and uncharged
nonpolar and charged
polar and charged
polar and large
two of the above


19.  

Which one of the following statements is true about diffusion? (p. 145)

It is very rapid over long distances.
It requires expenditure of energy by the cell.
It is a passive process.
It occurs when molecules move from a region of lower concentration to a region of higher concentration.
It requires integral proteins of the cell membrane.


20.  

The concentration of solutes in a red blood cell is about 2%. Sucrose cannot pass through the membrane, but water and urea can. Osmosis would cause red blood cells to shrink the most when immersed in which of the following solutions? (p. 146)

a hypertonic sucrose solution
a hypotonic sucrose solution
a hypertonic urea solution
a hypotonic urea solution
pure water


21.  

Imagine two solutions separated by a selectively permeable membrane that allows water to pass, but not sucrose or glucose. The membrane separates a 0.2-molar sucrose solution from a 0.2-molar glucose solution. With time, how will the solutions change? (p. 146)

Nothing happens because the two solutions are isotonic to one another.
Water enters the sucrose solution because the sucrose molecule is a disaccharide and thus larger than the monosaccharide glucose.
Water leaves the sucrose solution because the sucrose molecule is a disaccharide and thus larger than the monosaccharide glucose.
The sucrose solution is hypertonic and will gain water because the total mass of sucrose is greater than that of glucose.
After the sucrose dissociates to two monosaccharides, water will be osmostically drawn to that side of the membrane.


22.  

The diffusion of water across a selectively permeable membrane is called _____. (p. 146)

active transport
osmosis
exocytosis
passive transport
facilitated diffusion


23.  

The internal solute concentration of a plant cell is about 0.8 M. To demonstrate plasmolysis it would be necessary to suspend the cell in what solution? (p. 147)

distilled water
0.4 M
0.8 M
1.0 M
any of the above


24.  

Which of these situations accurately represents osmoregulation in organisms? (p. 146)

Freshwater fish must all be isotonic to their environments.
Marine animals cannot be isotonic to seawater.
Plant cells need a hypotonic environment for their cells to stay turgid.
Seawater is hypotonic to human cells.
Freshwater protozoa have short life cycles because they eventually burst from taking in too much water.


25.  

Green olives may be preserved in brine, which is a 20–30% salt solution. How does this method prevent contamination by microorganisms? (p. 146)

Bacterial cell walls are shrivelled up by salt, causing the cell to burst.
High salt concentrations lower the pH, thus inhibiting the process of glycolysis.
High salt concentrations raise the pH, thus inhibiting the process of glycolysis.
Bacteria can't survive in a hypotonic solution because of pressure on the cell wall.
Bacteria can't survive in a hypertonic solution because they lose water.


26.  

Cells A and B are the same size and shape, but cell A is metabolically quiet and cell B is actively consuming oxygen. Oxygen will diffuse more quickly into cell ___ because _____________. (p. 145)

A ... the diffusion gradient there is shallower
A ... its membrane transport proteins will not be saturated
B ... the diffusion gradient there is steeper
B ... the oxygen molecules inside cell B have a higher kinetic energy.
A ... needs the oxygen in order to revive.


27.  

Plant cell cytoplasm is typically more concentrated than its environment, yet plant cells do not swell and burst because _____. (p. 147)

the negative osmotic potential due to charged ions is counteracted by positive osmotic potential due to macromolecules
they actively transport ions through their plasmodesmata
their pressure potentials rise until they are equal but opposite in sign to their osmotic potentials
their cell walls seal out any influx of water
plants actively excrete water from individual cells


28.  

Sea water is dangerous to drink because ___________. (p. 146)

one cup of sea water contains enough sodium to poison you
sea water is hypertonic to your body tissues and drinking it will cause you to lose water by osmosis
sea water is isotonic to your body fluids and you will absorb too much water, causing your cells to burst
the salt causes hypertension and you will promptly die of a stroke
it contains toxic levels of iodine


29.  

Which of the following would be least likely to diffuse through a cell membrane without the help of a transport protein? (p. 144)

a large polar molecule
a large nonpolar molecule
oxygen
a small nonpolar molecule
any of the above would easily diffuse through the membrane


30.  

Which of these statements describes what occurs in facilitated diffusion? (p. 147)

Facilitated diffusion is another name for osmosis.
Facilitated diffusion of solutes occurs through phospholipid pores in the membrane.
Facilitated diffusion requires energy to drive a concentration gradient.
Facilitated diffusion of solutes occurs through protein pores in the membrane.
There is only one kind of protein pore for facilitated diffusion.


31.  

Which one of the following is NOT involved in facilitated diffusion? (p. 147)

a concentration gradient
a membrane
a protein
an outside energy source
all the above are involved


32.  

Which of the following enables a cell to pick up and concentrate a specific kind of molecule? (p. 148)

passive transport
diffusion
osmosis
receptor-mediated endocytosis
exocytosis


33.  

Which of the following is a difference between active transport and facilitated diffusion? (p. 147)

Active transport involves transport proteins and facilitated diffusion does not.
Facilitated diffusion can move solutes against a concentration gradient and active transport cannot.
Facilitated diffusion requires energy from ATP and active transport does not.
Facilitated diffusion involves transport proteins and active transport does not.
Active transport requires energy from ATP and facilitated diffusion does not.


34.  

The result of the operation of an electrogenic pump would be _____. (p. 150)

cell lysis
a voltage difference across the membrane
plasmolysis
a cell with a positively charged interior
a cell with a high internal concentration of protons


35.  

Active transport requires a cell to expend energy. Which of the following statements is NOT true? (p. 148)

Active transport often involves the passage of two different solutes across a membrane in opposite directions.
Active transport uses ATP as its energy source.
Active transport usually goes with the concentration gradient.
Active transport requires a protein carrier.
All of the above are true.


36.  

The sodium-potassium pump is an example of _____. (p. 149)

facilitated diffusion
transport by a mobile carrier
ion movement through a gated channel
active transport
coated-pit endocytosis


37.  

Glucose is a six-carbon sugar that diffuses slowly through artificial membranes. The cells lining the small intestine, however, rapidly move glucose from the gut into their cytoplasm. This occurs no matter whether the gut concentrations of glucose are higher or lower than the glucose concentrations in intestinal cell cytoplasm. Using this information, which transport mechanism is most likely to be responsible for the glucose transport in intestinal cells? (p. 148)

simple diffusion
phagocytosis
active transport
exocytosis
facilitated diffusion


38.  

A nursing infant is able to obtain disease-fighting antibodies, which are large protein molecules, from its mother's milk. These molecules probably enter the cells lining the baby's digestive tract via _____. (p. 151)

osmosis
passive transport
exocytosis
active transport
endocytosis


39.  

Which of these statements is true about cholesterol metabolism? (p. 151)

Cholesterol circulates in the blood and is deposited on blood vessels.
Cholesterol is formed because it is a waste product of fat metabolism.
The kidneys maintain cholesterol balance.
Hypercholesterolemia is a disease induced by a faulty diet.
Cholesterol is dangerous because it creates layers of fat in the heart muscle.


40.  

Which one of the following terms specifically refers to the intake of very large particles by cells? (p. 151)

phagocytosis
exocytosis
pseudocytosis
osmosis
pinocytosis


41.  

Some liver cells ingest bacteria, a function probably accomplished by _____. (p. 151)

pinocytosis
phagocytosis
receptor-mediated endocytosis
exocytosis
passive transport

   



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© 2002 Pearson Education, Inc.,
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