Download Chapter 5 Problem set

Chapter 5 Problem set
Matching
Choose the most appropriate answer for each of the following.
1____ fluid mosaic model
2. ____ Transport proteins
3. ____ freeze-fracturing and freeze-etching
4. ____ recognition proteins
5. ____ cholesterol and phytosterol
6. ____ phospholipid
7. ____ lipid bilayer
8. ____ adhesion proteins
9. ____ centrifuge
10. ___ receptor proteins
A. Oligosaccharide chains identify specific cell
types
B. Two layers of phospholipids, the structural
basis of cell membranes
C. Bind extracellular substances such as
hormones that trigger changes in cell activities
D. Separates cell components according to their
relative densities
E. W ater-soluble substances move through their
interiors; also bind and release molecules or ions to
move them through membranes
F. Phosphate-containing head and two fatty acid
tails attached to a glycerol backbone
G. Helps cells of the same type locate and stick to
one another
H. Determination of the nature of cell membranes
by observation
I. The most abundant sterols in animal and plant
membranes, respectively
J. A mixture of phospholipids, glycolipids,
sterols, and proteins; motions and interaction of
component parts
Fill-in-the-Blanks
Membranes show selective ______________________ in that they allow some substances but not others
to cross them in certain ways, at certain times. __________________ refers to the number of molecules
of a substance in a specified region, as in volume of fluid or air. A __________________ gradient is a
difference in the number of molecules or ions of a given substance in two different regions. When like
molecules move down their concentration gradient, it is called.______________________ ; this is a key
factor in moving substances across cell membranes and through fluid portions of cytoplasm. When the
concentration gradient is steep, diffusion is (choose one) ( ) slower ( ) faster. As the gradient decreases
and the number of molecules moving down the gradient decreases, diffusion is (choose one) ( )
slower ( ) faster. When the net distribution of molecules in a diffusion system is nearly uniform in the
tow adjoining regions, it is called dynamic.___________________. Diffusion {choose one) ( ) slower ( )
faster at higher temperature.; this is due to more rapidly moving molecules that collide more often. If a
difference in charge exists between two adjoining regions, the rate and direction of diffusion may be
changed by an _______________________ gradient. Within a cell, the side of the membrane that is
negatively charged will exert a(n) (choose one) ( ) attraction ( ) repulsion for positive sodium ions and
enhance the low of sodium across the membrane. A difference in pressure, and the . .gradient between
two adjoining diffusion regions, can also influence the rate and direction of diffusion.
Matching
Choose the most appropriate answer for each of the following
A. Refers to the relative solute concentrations of two
fluids
B. Having the same solute concentrations
C. Mass movement of one or more substances in
response to pressure, gravity, or another external
force
D. The amount of force preventing further inward
diffusion of water
E. The fluid on one side of a membrane that contains
more solutes than the fluid on the other side of the
membrane
F. The diffusion of water in response to a water
concentration gradient between two regions separated
by a selectively permeable membrane
G. Osmotically induced shrinkage of cytoplasm
H. The fluid on one side of a membrane that contains
fewer solutes than the fluid on the other side of the
membrane
I. A fluid force exerted against a cell wall and/or
membrane enclosing the fluid
1. ____bulk flow
2. ____ osmosis
3. ____ tonicity
4. ____ hypotonic solution
5. ____ isotonic solutions
6. ____ hydrostatic pressure
7. ____ osmotic pressure
8. ____ plasmolysis
9. ____ Hypertonic
Choice
For the following question choose the best fit,
a. passive transport
b. active transport
c. applies to both active and passive transport
1.____ The calcium pump
2.____ Part of the transport protein closes in behind the bound solute - and pan opens up to the opposite side
of the membrane
3.____ Involves a carrier protein that has not been energized
4.____ A carrier protein has a specific site that weakly binds a substance
5.____ At any give time, the net direction of movement depends on how many solute molecules make
random contact with vacant binding sites in the interior of proteins
6.____ The transport protein must receive an energy boost, usually from ATP
7.____ Solute binding to a carrier protein leads to changes in protein shape
8.____ The sodium-potassium pump
Matching
1. ____ exocytosis
2. ____ receptor-mediated endocytosis
3. ____ bulk-phase endocytosis
4. ____ Phagocytosis
5. ____ Membrane cycling
A. A cell engulfs microorganisms, large edible
particles, and cellular debris.
B. Membrane initially used for endocytic vesicles
returns receptor proteins and lids back to the plasma
membrane.
C. Vesicles form around small volumes of extracellular
fluid of various content
D. A cytoplasmic vesicle moves to the cell surface, its
own membrane fuses with the plasm membrane
while its contents are released to the environment.
E. Chemical recognitions and biding of specific
substance; pits of clathrin baskets sink into the
cytoplasm and close on themselves.
1.______________________________________Protein
2. _____________________________________ Protein
3. ___________________ ___________________________Protein
4. ___________________ ____________________________ Protein (open)
5. ___________________ ____________________________ Protein (closed)
6. ___________________ ____________________________ Protein
7. ______________________________________Protein
8. ______________________________________Protein
9. ______________________________________Protein
10. ______________________________________Protein
11. ______________________________________
True/False
If the statement is true, write a T in the blank. If the statement is false, make it correct by changing the underlined
word(s) and writing the correct word(s) in the answer blank.
____22. Because membranes exhibit selective permeability, concentrations of dissolved
substances can increase on one side of the membrane or the other.
____23. A water concentration gradient is influenced by the number of solute molecules present
on both sides of the membrane.
____24. The relative concentrations of solutes in two fluids is referred to as isotonic.
____25. An animal cell placed in a hypertonic solution would swell and perhaps burst.
____26. W ater tends to move from hypotonic solutions to areas with more solutes.
____27. Physiological saline is 0.9 percent NaCI; red blood cells placed in such a solution will
not gain or lose water; therefore, one could state that the fluid in red blood cells is
hypertonic.
____28. A solution of 80 percent water, 20 percent solute is more concentrated than a solution
of 70 percent water, 30 percent solute.
____29. The movement of water molecules and solutes in the same direction in response to a
pressure gradient is called osmosis.
____30. Plant cells placed in a hypotonic solution will swell.
Self-Quiz
1. W hite blood cells use to devour disease agents
invading your body. .
a. diffusion
b. bulk flow
c osmosis
d. phagocytosis
2. cells depend on the calcium pump mechanism
a. Intestine
b. Nerve
c. Muscle
d. amoeba
3. Proteins bind extracellular substances, such as
hormones, and bring about changes in cell activities.
a. Receptor
b. Adhesion
c. Transport
d. Recognition
4. In a lipid bilayer, tails point inward and
form a(n)
region that excludes water.
a. acidic
b. basic
c. hydrophilic
d. hydrophobic
5. A protistan adapted to life in a freshwater pond is
collected in a bottle and transferred to a saltwater bay.
W hich of the following is likely to happen?
a. The cell bursts.
b. Salts flow out of the protistan cell.
c. The cell shrinks. _
d. Enzymes flow out of the protistan cell.
6. W hich of the following is not a form of active
transport?
a. Sodium-potassium pump
b. Endocytosis
c. Exocytosis
d. Bulk flow
7. W hich of the following is not a form of passive
transport?
a. Osmosis
b. Passive transport
c. Bulk flow
d. Exocytosis
8. O 2, CO 2, H 2O, and other small, electrically neutral
molecules move across the cell membrane
by___________ . .
a. electric gradients
b. receptor-mediated endocytosis
c. passive transport
d. active transport
9. Ions such as H+, Na +, K +, and Ca +2 move across cell
membranes by _____________
a. receptor-mediated endocytosis
b. pressure gradients
c. passive transport
d. active transport
10. Receptors, pits, and clathrin baskets participate in
a. passive transport
b. receptor-mediated endocytosis
c. bulk-phase endocytosis
d. active transport