Download 1) The resting membrane potential is: a) 0 mV, charge is balanced at

1) The resting membrane potential is:
a) 0 mV, charge is balanced at rest
b) Negative inside because potassium can diffuse out of the cell
c) Negative inside because Cl- concentrations are higher inside the
cell
d) Negative outside because sodium can diffuse into the cell
2) Which of the following is a true statement about cells in the resting
state:
a) Chloride moves into the cells because the concentration of chloride
is higher inside the cell than outside the cell
b) Large anions (A-) moves out of the cell because it has a higher
concentration inside the cell than outside the cell
c) Sodium moves into the cell because it has a higher concentration
outside the cell than inside the cell
d) Voltage gated sodium channels are closed
3) The action potential threshold stimulus causes:
a) chloride to enter the cell
b) Voltage gated sodium and potassium channels to open
c) Voltage gated sodium channels to inactivate
d) Release of Ca++ from the axon
4) Cardiac muscle:
a) Is striated
b) Has no electrical connection between cells
c) Is not striated
d) Has cells that are long and unbranched
5) This causes vesicles to migrate and release of neurotransmitter in the
chemical synapse:
a) Increased dopamine
b) Monoamine oxidase
c) Increased calcium
d) Increased potassium
6) Prozac increases the amount of serotonin present in the synapse by:
a) Acting as a selective serotonin reuptake inhibitor
b) Increasing tryptophan levels
c) Blocking the enzymatic degradation of serotonin
d) Increasing serotonin synthesis
7) When the sarcomere shortens:
a) Calcium levels decrease
b) Myosin pulls on the actin filament
c) ATP must not be present
d) Potassium is bound to troponin
8) This negatively charged ion is found at high concentrations (i.e., 120
mM) outside the cell:
a) Sodium
b) Ac) Chloride
d) Bicarbonate
9) Excitable cells such as neurons
a) Have a resting membrane potential of around +35 mV
b) Have a resting membrane potential of around -70 mV
c) Have internal potassium concentrations that are the same as
potassium concentrations outside the cell.
d) Have a resting membrane potential of around 0 mV
10) Smooth muscle cells are:
a) striated
b) longer than skeletal muscle cells
c) connected to each other by gap junctions
d) used by the hand for gripping
11) This cord-like protein physically covers the myosin binding sites of
actin, preventing muscle contraction unless calcium is present:
a) Unsaturated fatty acid
b) desaturase
c) Tropomyosin
d) Myosin
12) The diagram below shows voltage gated channels. When the
voltage gated channels are in this state:
a) The membrane potential will remain stable
b) Sodium will leave the cell
c) The membrane potential will rapidly become more positive
d) The membrane potential will become hyperpolarized
13) If a person has reduced levels of serotonin, this results in:
a) Clinical depression
b) Male erectile disfunction
c) paralysis
d) Schizophrenia
14) Which isoform of myosin listed below is used for slow endurance
muscle contraction:
a) Type I
b) Type IIx
c) Type IIa
d) Type Ib
15)
a)
b)
c)
d)
16)
a)
b)
c)
d)
17)
a)
b)
c)
d)
Calcium induces muscle contractions by
Causing actin monomers to assemble into a filament
Depolarizing the membrane
making ATP available to bind to myosin head
allowing the myosin head to bind to actin filament
Type II myosin is:
found in fast twitch muscle fibers
found in slow twitch muscle fibers
only found in rodents
activated by chloride
The effect of having Schwann cells and nodes of ranvier on axons is:
to slow down action potential propagation
to increase the height of the action potential peak
to speed up action potential propagation
to decrease the height of the action potential peak
18)
a)
b)
c)
d)
19)
a)
b)
c)
d)
20)
a)
b)
c)
d)
21)
a)
the picture above shows:
A motor neuron innervating a smooth muscle fiber
An electrical synapse
The cross section of a skeletal muscle fiber
The serotonergic synapse
The thick filaments of the sarcomere are made out of:
Actin
Myosin
Sarcoplasmic reticulum
sarcoplasm
When a membrane depolarizes, the membrane potential becomes:
More negative
More positive
Stays the same
Speeds up
Which of the following allows the muscle to contract:
Calcium release from the sarcoplasmic reticulum
b)
c)
d)
22)
a)
b)
c)
d)
23)
a)
b)
c)
d)
24)
a)
b)
c)
d)
25)
a)
b)
c)
d)
Norepinephrine taken up into the axon terminus
Actin pulling on other actin filaments
Release of nitric oxide (NO)
Tetrodotoxin:
Blocks chloride channels
Blocks myosin binding to actin
Is found in pufferfish
Opens voltage gated potassium channels
Skeletal muscle cells
Are always dividing
Are always short in length
Are found in the small intestine
Are also called muscle fibers
In muscle contraction and sarcomere shortening:
Acetylcholine binds to myosin
ATP causes myosin to unbind from actin
Muscle contraction cannot occur if calcium is present
Acetylcholine binds to actin
The duration of the action potential is:
A few nanoseconds
A few milliseconds
Several seconds
A few minutes
26) When the voltage gated channels of the neuron are in the
configuration shown above:
a) The membrane potential stays at +30 mV for several minutes
b) Potassium diffuses out of the cell making the membrane potential
more positive
c) The membrane potential drops back to the resting potential
d) Potassium rapidly diffuses into the cell
27) In the sliding filament model of muscle contraction:
a) Hydrolysis of ATP causes the myosin head to cock
b) Hydrolysis of ATP causes calcium to bind to actin
c) The release of ADP and Pi causes the myosin head to attach to actin
d) The release of ADP and Pi causes calcium to bind to actin
28) Substance P is involved in:
a) Thermal regulation
b) Osmoregulation
c) Nitrogen wastes
d) Pain
29) Which of the following is an amino acid neurotransmitter:
a) Dopamine
b) Carbon monoxide (CO)
c) Calcium
d) Glycine
30) The head of the myosin cocks when:
a) ATP binds to it
b) ATP is hydrolyzed to ADP and Pi
c) ADP and Pi are released
d) ATP is synthesized from ADP and Pi
31) What can happen when neurotransmitter binds to ion channels on
the post synaptic membrane?
a) Ion channels open
b) a depolarization or hyperpolarization occurs
c) a depolarization is stimulatory
d) all of the above
32) The sodium-potassium ATPase
a) Pulls against myosin in muscle contraction
b) Makes [K+] higher inside the cell and [Na+] higher outside the cell
c) Is a neurotransmitter
d) pumps 3 K+ out of the cell and 2 Na+ into the cell at the expense of 1
ATP.
33) The propagation of the action potential along an axon:
a) can be as high as 10 meters per second or 22 mph
b) can be as high as 100 meters per second or 225 mph
c) can be as high as 1000 meters per second or 2250 mph
d) can be as high as the speed of light