1. An equivalent circuit for the membrane, shown in the first lecture, plotted an exponential decrement of voltage as a function of distance. Name one of the electrical components that was shown in that model.

resistor, capacitor, battery

2. "Cells of an exocrine gland release their product into a duct." Where do cells of an endocrine gland release their product?

the blood stream (capillaries)

3. What affect does cortisol have on the anterior pituitary gland?

negative feedback, inhibit ACTH release

4. "A hormone is diluted by the blood stream, and so a lot more chemical signal is needed than for the a neurotransmitter from the spinal motor neuron to the muscle cell." Why is a smaller amount of hormone required when the hypothalamus signals to the anterior pituitary?

the portal system delivers it more discreetly

5. "A semipermeable membrane is part of the explanation for osmosis." (1) Permeable to what AND (2) not permeable to what?

1-water, 2-larger molecules like glucose, hemoglobin, carbonic anhydrase

6. Say something about why the movement of glucose across the membrane is called facilitated diffusion.

diffusion because it is passive (not requiring energy), facilitated because the GLUT transporter is needed

7. "Picture an area where the gravel has been lightly shadowed by a light snow blowing from one direction." Answer either (1) What is this technique called? (2) What do the P-face particles represent? or (3) What heavy metal is used for shadowing?

1 freeze fracture 2 membrane proteins 3 platinum

8. How is it that a protein such as rhodopsin can reside in a membrane whose interior is so hydrophobic?

its alpha helices are mostly hydrophobic amino acids

9. Tay Sachs disease: Answer either (1) Why is it called a lysosomal storage disease? (2) What molecule fails to turn over? or (3) Why would the eye and brain be affected first?

1 the substance the lysosomes fail to degrade accumulate in lysosomes 2 a glycolipid 3 there are lots of membranes with lots of membrane lipids

10. "Homeostasis of calcium ions in the blood stream is very important." Name one of the three hormones dedicated to this regulation.

parathormone, calcitonin and vitamin D

11. In contrast with the G protein coupled receptor, why is the nicotinic receptor more direct?

an ion channel is more direct than a signal transduction cascade

12. What membrane protein uses energy derived from ATP to move sodium and potassium ions across the cell membrane?

sodium pump = sodium potassium pump = Na+K+ATPase

13. "Receptor mediated endocytosis" - Say something about EITHER (1) What is on the outside of the vesicle? OR (2) What is on the inside of the vesicle?

1-clathrin (that makes a coated vesicle look coated), 2-the receptor for what is being endocytosed plus what is being endocytosed like LDL or HDL

14. In discussing Ohm's law, what is the slope of the line when I (Y axis, ordinate) is shown as a function of V (X axis, abscissa)?

the conductance (g)

15. Voltage is shown to change as an exponential function of time because of what particular component in an equivalent circuit model?


16. Who came up with the idea that the chemical gradient is equal and opposite to the electrical gradient?

that would be the equation attributed to Nernst, the chemistry Nobel prize winner

17. "You can't have more current flowing into one place than flows out of that place," is my casual wording of one of (whose?) laws that applies to circuits.


18. "An action potential depolarizes the membrane ahead of it to threshold." What is it about the space constant that relates to invertebrates having giant axons?

space constant increases with the square root of the radius

19. "The action potential starts at the axon hillock and goes down the axon to the terminals." What property of the action potential assures the unidirectional propagation of the action potential?

refractory period, you cannot generate an action potential right after an action potential

20. In the peripheral nervous system, the action potential... (answer either) (1) jumps from one (fill in the blank) to the next OR (2) in other words, it jumps past (what?).

node of Ranvier, Schwann cell = patch of myelin

21. "The multiple layers of membrane in myelin have less capacitance than one layer of membrane would have." How would the resistance of multiple layers relate to the resistance of one layer?

multiple layers would be much higher

22. Why, according to the idea of Experimental Autoimmune Encephalitis (EAE), do scars form in the brains of people with multiple sclerosis?

the immune system attacks the white matter

23. What is the molecular mechanism for channel inactivation?

a stopper formed by amino acids near the n-terminus plugs the channel

24. For stretch of the extensor to mediate contraction of the extensor, there is a monosynaptic reflex arc. What needs to be added to this circuit for there to be a corresponding inhibition of the flexor?

an inhibitory interneuron

25. How did calcium ions become available to bind to the synaptic vesicle protein synaptotagmin?

they came in through the voltage gated calcium channel at the terminal upon arrival of the action potential

26. An action potential arrives at the axon's terminal. What does not happen in the case of poisoning with Clostridium botulinum?

vesicles are not released

26. "Vagus-stuff slows the heart." Answer EITHER (1) What major subdivision of the autonomic nervous system does vagus-stuff come from? OR What chemical is vagus-stuff?

parasympathetic, acetylcholine

27. "Vagus-stuff slows the heart." Answer EITHER (1) What major subdivision of the autonomic nervous system does vagus-stuff come from? OR What chemical is vagus-stuff?

parasympathetic, acetylcholine

28. Some acetylcholine receptors are channels and they are called nicotinic. The other acetylcholine receptors ANSWER EITHER (1) are what type of signaling molecule? OR (2) are called by what pharmacological name?

g protein coupled receptor, muscarinic

29. What molecule does malathion INHIBIT (leading the heart to stop)?


30. "Caffeine potentiates the 'upper' action of epinephrine and norepinephrine by..." answer either (1) inhibiting the breakdown of what molecule? OR (2) inhibiting what enzyme?


31. How are melanin and dopamine related?

both have l-DOPA as a precursor, substantia nigra is dark because of melanin and produces dopamine

32. In the thoraco-lumbar system, in the sympathetic chain of ganglia, postganglionic cells use nicotinic receptors to what neurotransmitter?


33. Before they knew the chemical identity (NO = nitric oxide) they used an operational name (EDRF = endothelial derived relaxation factor). Answer either (1) What is housed in endothelial cells to make NO? or (2) What is it that was made to relax by this factor?

eNOS (endothelial Nitric Oxide Synthase), smooth muscle in arterioles to the corpus cavernosum

34. Why would an alpha-1 adrenergic agonist be useful as a nasal decongestant?

mediate vasoconstriction

35. Why is the word "belladona" used in reference to atropine?

women are more beautiful if they dilate their pupils as a cosmetic procedure

36. "Power stroke causes filaments to slide; ADP is released." Answer either (1) What was released just before the ADP was released? (2) ADP was released from what molecule? Or (3) What comes in to fill the empty pocket where the ADP had been?

phosphate, myosin, ATP

37. Why, in terms of actin and myosin, is the tension a muscle can achieve lower for a muscle at 160% of its resting length than for a muscle at its "ideal" resting length?

less overlap of actin and myosin

38. For myasthenia gravis, answer either (1) Why do the patients experience muscular weakness? OR (2) What would be given to help the patient?

too few nicotinic channels, neostigmine (acetylcholinesterase inhibitor)

39. How, and under what circumstances, does tropomyosin keep myosin from binding to actin?

it hides myosin's binding sites on actin unless calcium binds troponin

40. In muscle, hemoglobin would offload oxygen to myoglobin. Explain in terms of the oxyhemoglobin dissociation curve.

since the myosin curve is to the left of the hemoglobin curve, it means that myoglobin has a higher affinity for oxygen

41. Nicotinic receptor, sarcoplasmic reticulum calcium channel, voltage-gated sodium channel. One channel in the muscle cell is missing from this list. Answer either (1) for what ion? or (2) in what specific location?

calcium (2) T-tubules

42. Say something (else) about the properties of the type of muscle fiber that is sometimes called fast twitch.

white meat, anaerobic, strong but not enduring

43. What does the reaction of phosphocreatine to creatine achieve?

it generates ATP from ADP in muscle

44. What do varicosities in autonomic neurons do (where they are near smooth muscle cells)?

release neurotransmitter

45. Salts of cholesterol - answer either (1) Why are they useful in digestion? Or (2) Where do they come from?

emulsify fats, liver

46. Glycerol is a 3 carbon chain with an alcohol (-OH) on each carbon. Each fatty acid that gets linked to glycerol has an acid (-COOH) group. How were the alcohols and acids altered to make the ester bonds?

water was taken out

47. What is so special about carbon that makes it the common denominator of all organic molecules?

it makes 4 bonds

48. Urea is manufactured in your body from carbon dioxide plus what waste?


49. "The third phosphate of ATP is not just broken off as inorganic phosphate, but is actually delivered to a molecule." Regarding the action of the insulin receptor, what molecule acquires phosphate from ATP?

the receptor is phosphorylated at a tyrosine residue (then other cascade molecules)

50. During "fasting" (a few hours after a meal before the next meal) where does glucose come from to maintain blood glucose levels?

glycogen in liver

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last updated Sept 20, 2016