(Here you will find answer keys for homework or quizzes as well as unedited responses on exams from your classmates)

 

QUIZ 1

 

1.  The Na/K ATPase pump is an example of how molecules are transferred across the phospholipid bilayer by the process of

            a.         simple diffusion

            b.         facilitated transport

            c.         secondary active transport

            d.         primary active transport

ANSWER:  d.

           

2.  If you placed one of your cheek cells (given: The ICF = 120 mM NaCl ) in a solution of 300 mM glucose, and you assume neither compound could permeate the PL bilayer, through the process of osmosis your cell would

            a.         crenate

            b.         lyse

            c.         be happy as a clam (normal cell volume)

            d.         cannot determine by the provided information

ANSWER:  a.

 

3.  The Na/K ATPase pump uses a method called __________________   __________________

or successive phosphorylation/dephosphorylation cycles to change its configuration and pump ions against their concentration gradients.

ANSWER:  Molecular Peristalsis

           

4.  T or F   (please circle)

 

If a cell has an electrical disturbance of at least 25 mV, it will always fire an action potential because of the ALL-or-NONE principle.

ANSWER:  F

 

5.  Which of the following physiological processes requires no ATP expenditure?

            a.         endocytosis

            b.         exocytosis

            c.         osmosis

            d.         facilitated diffusion

            e.         two of the above

ANSWER:  e.

 

6.  Which of the following organic molecules would be classified as a protein?

            a.         molecules that are formed from dehydration reactions

            b.         molecules that contain free fatty acids

            c.         molecules that are produced from peptide bond formations

            d.         steroids

            e.         DNA

            f.          glycogen

            g.         ketone bodies

ANSWER:  c.


7.  If a cell had the following ionic concentrations and permeabilities, about at what voltage would you predict an action potential would change polarity (peak of the action potential spike)?

HINT: You can decide whether to use Nernst or Goldman.

 

PK = 10

PNa = 10,000

Assume mammalian temperature of 37 degrees.

[K+]o = 40 mM

[K+]i = 365 mM

[Na+]o = 410 mM

[Na+]i = 55 mM

 

Please show all calculations.                          Answer: ______________________________

 

 

Ena = 60/+1 log [(410)/(55)] = 52.345 mV = 52 mV

 

 

 

 

 

8.  If the resting potential of the cell in #7 was -85 mV, at what voltage would this action potential begin to fire fully?     HINT: Threshold.

 

Absolute value of -85 mV + 52 mV = 137 mV * 0.15 = 20.55 mV, 21 mV

-85 + 21 = -64 mV is the Threshold voltage at which the AP will fire fully.

 

Please show all calculations.                          Answer: _________________________________

 

 

9.  Write one sentence describing the importance of the phospholipid bilayer for the physiologist =

ANSWER:  Many importances that you can list!!!

 

10.  T or F (please circle)

 

According to Fick’s Law of Diffusion, the diffusion rate or flux is greatest when the molecule to be transported has a high molecular weight and has to traverse a large cross sectional area.

ANSWER:  F

 

11.  If an action potential (AP) reaches threshold, where in the neuron will the AP “spike” be initiated?

            a.         the dendrite

            b.         the soma

            c.         the axon hillock

            d.         the synaptic terminals

            e.         the sodium/potassium ATPase pump

ANSWER:  c.

 

ANSWER KEY TO the First Hour Exam:

 

 

1a

2c

3a

4c

5e

6e

7d

8e

9b

10c

11a

12d

13b

14b

15c

16d

17c

18d

19c

20a

21c

22b

23c

24c

25e

26a

27d

28e

29c

30a

31d

32c

33d

34b

35d

36b

37c

38c

39a

40d

41a

42a

43a

44b

45a

46b

47a

48b

49b

50a

 

QUIZ 2

 

1.    Which of the following types of muscles are striated and involuntary?

a.                skeletal

b.               cardiac

c.                smooth

d.               b and c

e.                a and b

f.                none of the above

ANSWER:  b.

 

2.    A single muscle CELL is known as

a.                a sarcomere

b.               a myofibril

c.                one actin and one myosin filament

d.               a motor unit

e.                a muscle fiber

ANSWER:  e.

 

3.  Action potentials move perpendicular to the muscle fibers by entering the transverse tubules that are located where along the sarcomere?

a.                A band

b.               Z band

c.                M band

d.               I band

e.                Z and I bands

f.                A and I bands

ANSWER:  f. (e. on your key!)

 

4.    Which of the following “contractile proteins” functions to block the thick filament from accessing a binding site to form a cross bridge but does not physically bind calcium?

a.                actin

b.               troponin

c.                tropomysin

d.               tropoactin

e.                myosin

ANSWER:  c.

 

5.    In relation to skeletal muscle mechanics, during which phase of the twitch would calsequestrin have its highest activity?

a.                latency period

b.               contraction

c.                relaxation

d.               summation

e.                tetany

ANSWER:  c.

 

 

6.    T or F (please circle)

The white matter is responsible for integrating reflex activity using polysynaptic and monosynaptic connections of afferent and efferent neurons, respectively.

ANSWER:  F

 

7.    Which of the following does not mediate or assist in smooth muscle contraction of your arteries?

a.                inositol 1,4,5-trisphosphate

b.               dense bodies

c.                troponin

d.               sarcoplasmic reticulum

e.                ALL are helpful in smooth muscle contraction

ANSWER:  c.

 

8.    During a skeletal muscle contraction, the length of the sarcomere shortens due to a decrease in size of ALL but which band?

a.                A band

b.               Z band

c.                H band

d.               I band

e.                All of the above will shorten

ANSWER:  a.

 

9.    If the cross bridge cycle was in a stage where there was no calcium, the orientation of the myosin head was at 90 degrees in relation to the tail of the molecule, and there was ATP available, then the muscle would be in which stage of contraction?

a.                the actin and myosin would be touching each other

b.               it would be in the power stroke

c.                actin and myosin would be detached and ATP would undergo hydrolysis

d.               it would be in a rigor mortis locked complex

ANSWER:  c.

 

10.    Which of the following activities is performed principally by the somatic nervous system?

a.                beating of your heart

b.               bowel movements

c.                running up the stairs

d.               swallowing

e.                breathing

ANSWER:  c.

 

11.    Which portion of the spinal column has emerging spinal nerves that would innervate the chest region?

a.                thoracic

b.               lumbar

c.                cervical

d.               pelvic

e.                dorsal root ganglion

ANSWER:  a.