Select the one that is best answer:
1) As regard carrier mediated transport all are true except :
a) can be utilized for active transport or facilitated diffusion .
b) exhibit competitive inhibition .
c) can be uphill or downhill .
d) energy can be supplied directly from ATP or indirectly or not
used at all .
e) Its net rate is limited .
2) Cell membranes :
a) act as semipermeable barriers essential for maintaining
intracellular composition different from the outside environment .
b) are responsible for forming compartment within cells .
c) A and B are correct .
d) of neurons and hepatocytes are the same structurally and
functionally .
e) all are correct .
3) Which of the following in most related to the fact that in the steady
state ( resting state ) the cell membranes are relatively more
permeable to K+ than to Na+ :
a) cells posses an outside - negative transmembrane resting
potential .
b) cells posses an inside - negative transmembrane resting
potential.
c) cells change volume in the presence osmotic pressure gradient .
d) normal cells show a progressive diminution in the internal K+
concentration in the steady state.
e) cell does not posse active ion transport system .
4) Which of the following best describe the process of diffusion :
a) A " downhill " process .
b) An " uphill " process .
c) A process by which only large molecular weight proteins may
move across biological membrane .
d) require metabolic energy .
e) depends on the balance between hydrostatic pressure and oncotic
pressure of plasma protein .
5) As regard ionic equilibrium potential all are correct except :
a) can be measured by Nernst equation .
b) It is due to charge separation .
c) its value depends an ionic concentration gradient .
d) the net current flow in zero .
e) for Na+ ( intracellular concentration : extracellular concentration
1 : 12 ) is 20 m volt .
6) The gap junction :
a) are absent in cardiac muscle .
b) are present but of little functional importance in cardiac muscle .
c) they conduct the cardiac impulse from the cardiac muscle fiber
to another.
d) are absent in smooth muscle .
e) none of the above is might .
7) Cell membrane :
a) consists almostly of protein .
b) consists almostly of fat .
c) are impermeable to fat soluble substances .
d) are freely permeable to electrolytes .
e) none of the above.
8) The primary force moving water across the cell membrane is :
a) active transport .
b) facilitated diffusion .
c) co- transport with glucose .
d) osmotic force .
e) antiport with H+ .
9) Osmosis :
a) movement of solvent across a semi permeable membrane from
an area where the hydrostatic pressure in high to an area of low
hydrostatic pressure .
b) movement of a solute across a semi permeable membrane from
an area of high solute concentration to an area of low solute
concentration .
c) movement of a solute across a semi permeable from an area low
solute concentration to an area of high solute concentration .
d) movement of a solvent across a semi permeable membrane from
an area of low solute concentration to an area of high solute
concentration .
e) none of the above is true .
10) The facilitated
except :
diffusion in characterized
by the following
a) diffusion occurs down a concentration gradient .
b) it needs a caisson protein .
c) it in not rate limitted .
d) no external energy is utilized .
e) depends on stereo specificity .
11) 5 ml blood was withdrawn from a man its freezing point is 0.54
C , the blood osmolarity could be:
a) 300 m.osm. / L .
b) 250 m.osm. / L .
c) 325 m.osm. /L .
d) 290 m.osm. / L .
e) 305 m.osm. / L .
12 ) One red blood cell of 100 μm shifted from plasma of 285
m.osm. / L to a solution of 325 m.osm. / L . the volume of the red
blood cell could be :
a) 80 μm.
b) 70 μm .
c) 100 μm .
d) 88 μm .
e) 82 μm.
13) Na+ - K+ ATP ase is activated by all the following except :
a) high intracellular [ Na+ ] .
b) high extra cellular [K+] .
c) availability of ATP .
d) cardiac glycosides .
e) thyroxine hormone .
14) The RMP :
a) is dependent an the membrane permeability to K+ .
b) is markedly altered is extracellular [Na+] in increased .
c) is usually equal to the equilibrium potential for Na+ .
d) at equals the equilibrium potential for K+ exactly .
e) fall to zero immediately when Na- K ATP ase in inhibited .
15) When you are given the following data :
- E Na+ = + 66 m.volt .
- E K+ = - 97 m volt .
- G K+ / GNa+ = 9/1 .
The RMP could be :
a) - 75 m.volt .
b) - 80.7 m.volt .
c) - 88.8 m.volt .
d) - 70 m.volt .
e) - 90 m.volt .
16) as regard Na+ and K+ channels during RHP all are true except :
a) m gate is closed .
b) h gate is not inactivated .
c) h gate is inactivated .
d) K+ channel is closed .
e) m gate is closed and h gate is opened.
17 ) When you are give the following data :
E Na =+60 m.volt
E K =-90 m.volt
GNa :GK = 1
Reversal potential for end plate potential could be :
a) -30 m. volt
b) -45 m. volt
c) + 30 m.volt
d) -15 m.volt
e) zero potential
18) When you give the following data :
ENa+ =+60 m.volt
EK+= -90 m.volt
Reversal polarity of action potential in nerve fiber occur where
GNa : GN is 4:1
magnitude of depolarization ( reversal of polarity ) could be :
a) -20 m.volt .
b) zero potential .
c) +10 m.volt .
d) +30 m.volt .
e) -45 m.volt .
19) Assuming that extra-cellular concentration of Na+ is 10 times its
intracellular concentration, the equilibrium potential for Na+ could
be the same as the equilibrium potential of Ca++ if the extracellular
concentration of Ca++ is :
a) 2 times the intracellular concentration of Ca++ .
b) 10 times the intracellular con. of Ca++ .
c) 20 times the intracellular conc. of Ca++ .
d) 100 times the intracellular conc. of Ca++ .
e) the same as the intracellular concentration of Ca+ .
20) The equilibrium potential for K+ and Na+ are -90 m.volt and
+60 mvolt respectively , it GK is 4 times the G Na the RHP is :
a) - 50 m. volt .
b) -60 m. volt .
c) - 70 m. volt .
d) -80 m. volt .
e) -90 m. volt .
21) A red blood cell is placed in a solution the cell initially shrinks
and than returns to its original volume the solution could be :
a) hyperosmolar and hypertonic .
b) hypoosmolar and hypotonic.
c) hyperosmotic and isotonic.
d) hyperosmolar and hypotonic .
e) hypoosmolar and hypertonic .
22) Following the intravenous administration of one liter of 150
mmol NaCL solution into normal person there will be :
a) a decrease in plasma Na+ concentration .
b) an increase in the osmolarity of ICF .
c) an increase in the osmolarity of ECF.
d) an increase in the volume of ICF .
e) an increase in the volume of ECF .
23) The IV administration of I L of 150 m.mol urea solution into a
person will results in all the following except :
a) a decrease in plasma NA+ concentration .
b) an increase in the osmolarity of ICF .
c) a decrease in the osmolarity of ECF .
d) an increase in the volume of ICF .
e) an increase in the volume of ECF .
24) A man has total body water 40 liter, of which 15L ECF of an
osmolarity 300 m.osmol /L , what would be the ICF osmolarity of 500
ml of 0.15 mol/L Nacl solution in aroused TV. :
a) 164 mos. /L .
b) 277 mos. /L .
c) 286 mos. /L .
d) 300 mos. /L .
e) 324 mos. /L .
25) Normal RBCs shifted from normal plasma to plasma made
hyperosmolar due to excess of urea, which is permeable to cell
membrane the results could be:
a) swelling of the shift RBCs.
b) shrinking of the shift RBCs..
c) shrinking of the shift transiently then return to the original
volume .
d) no change in cell volume at any time .
e) none of the above is correct .
Choose whether these statements are true or false :
26) A solution of impermeable solute as Na Cl or K Cl :
a) 200
b) 300
c) 400
d) 400
e) 300
m.osmol / L is hypotonic and hypoosmollar .
m.osmol/L is isotonic and isoosmolar .
m.osmol/L is isotonic and isoosmolar .
m.osmol / L is hyperosmolar and hypertonic .
m.osmol/L is iso-osmolar and hypotonic .
27) A solution of permeable solute as urea :
a)
b)
c)
d)
e)
200 m.osmol /L is hypoosmolar and hypotonic .
250 m.osmol /L is isotonic and isoosmolar .
300 m.osmol /L is isotonic and isoosmolar .
400 m.osmol /L is hyperosmolar and hypertonic .
400 m.osmol /L is hyperosmolar and hypotonic .
28) With regard to osmosis across the cell membrane :
a) water moves up its concentration gradient .
b) cells will swell in hypotonic solution .
c) the osmolarity of the solution indicates its tonicity .
d) proteins are the most important osmotically active solutes in the
extra cellular fluid .
e) increased intracellular hydrostatic pressure would help to oppose
osmotic swelling.
29) Depolarization :
a) refers to an increase in membrane potential (more negative inside ) .
b) the membrane potential in moving a way from the zero potential .
c) is associated with an increased membrane permeability to Na+ in
nerve and skeletal muscle .
d) will eventually close voltage gated Na+ channel .
e) will increase the gradient for K+ efflux .
30) Action potential :
a) are graded electrical events .
b) are conducted over the surface of excitable membrane .
c) are produced by subthreshold stimuli .
d) inhibit further stimulation during or immediately after the action
potential .
e) are associated with a repolarization phase caused by outward
movement of Cl .
31) Resting membrane potential of membrane :
a) is caused by selective permeability the membrane to different ions .
b) is caused by unequal distribution of ions along both sides of the
membrane .
c) the inward Na+ current exceeds the outward K+ current in the
steady state .
d) Na+ - K+ ATP ase has no role for its establishment .
e) shitted toward zero potential when Na+ channels is activated .
32) For voltage gated Na+ channels :
a) about 300 – 500 / μm in initial segment of the axon .
b) less than 200 at the node of ranvier .
c) their activation include changes is membrane potential could reach
action potential value .
d) are present at the motor end plate region .
e) dep. of the membrane induce activation and inactivation of these
channels .
33) As regard facilitated diffusion :
a) need carrier protein .
b) energy utilized is supplied indirectly from ATP .
c) occurs downhill .
d) at is a saturable process .
e) at has some characters common between passive diffusion and active
transport
34) Osmolarity :
a) at is the expression of concentration in osmol or m.osmol/L .
b) can be measured by depression of freezing point of the solution .
c) the plasma protein is the most osmotically active particles in the
plasma .
d) is equal for intra-cellular and extra-cellular compartment .
e) doesn't depend on the size or charge of the particles.
35) As regard depolarization :
a) the outward K+ current exceeds the inward Na+ current .
b) the inward Na+ current equal the outward K+ current .
c) the inward Na+ current exceed the outward K+ current .
d) eventually is terminated by Na+ channel inactivation .
Key of answers:
1) E
2) C
3) b
4) a
5) e
6) c
7) e
8) d
9) d
10) c
11) d
12) d
26
27
28
29
30
31
32
33
34
35
A(T)
A(T)
A(F)
A(F)
A(F)
A(T)
A(T)
A(T)
A(T)
A(F)
13) d
14) a
15) b
16) c
17) d
18) d
19) d
20) b
21 ) c
22) e
23) b
24) d
25) c
B(T)
B(F)
B(T)
B(F)
B(T)
B(T)
B(F)
B(F)
B(T)
B(F)
C(F)
C(F)
C(F)
C(T)
C(F)
C(F)
C(T)
C(T)
C(F)
C(T)
D(T)
D(F)
D(F)
D(T)
D(T)
D(F)
D(F)
D(T)
D(T)
D(T)
E(F)
E(T)
E(T)
E(T)
E(F)
E(T)
E(T)
E(T)
E(T)
36) e
37) e
38) c
39) d
40) d
41) b
42) d
43) a
44) b
45) b
46) c
47) d
48) d
49) b
50) c
51) a
52) d
53) c
54) d
55) b
56) b
57) a
58) c
59) b
60) c
61) b
62) c
63) c
64) e
65) c
66) c
67) b