HW Packet 2 - BY Topic - Homework 2 PDF

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BIO 12

Homework Packet 2

Saddleback College

Name:__________________________

CELL MEMBRANE, PROTEINS, AND MEMBRANE TRANSPORT Match each of the following terms with the description below. More than one term (a-c) may be used to match each description. Code answers on your scantron form. Choices may be used more than once. A. active transport 1. 2. 3. 4. 5.

B. simple diffusion

C. facilitated diffusion

uses cellular energy for transport of substrate transport of substrate occurs from a region of high to low substrate concentration transport requires a membrane carrier protein “uphill” movement of substrate (that is, against its gradient) energy for transport is provided by the substrate, not the cell

6. Small uncharged molecules, urea, gases and short chain alcohols a) require a carrier to get through the cell membrane b) pass freely through the lipid bilayer by diffusion c) do not pass through membranes at all 7. Amino acids and glucose, as well as ions and any charged species a) require a carrier to get through the cell membrane b) pass freely through the lipid bilayer by diffusion c) do not pass through any portion of the membrane at all 8. More than one selection may be correct. Select all choices that apply. Phospholipid molecules are a) have regions that are partly polar and partly nonpolar b) contain a negatively-charged phosphate group and a positively-charged nitrogen group c) are modified triglycerides d) are components of the cell membrane 9. The Na+-K+ pump is an integral membrane protein that transports Na+ ions ___the cell and K+ ions ____ the cell. a) into, into c) out of, out of b) into, out of d) out of, into

MEMBRANE POTENTIALS AND ACTION POTENTIALS 1. Sodium's electrochemical gradient drives it ___ the cell, and potassium’s drives it ___ the resting cell. a) into, out of c) out of, out of b) into, into d) out of, into 2.

In a neuron with a resting membrane potential of -65mV, the distribution of which ion across the neuronal membrane represents the greatest electrical potential? a) Potassium c) Sodium b) Chloride d) Calcium

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DENDRITES TO SYNAPSE

The Neuron A. Nodes de Ranvier

B. spinal cord

C. myelination

D. motor

E. sensory

AB. effector

AC. axon

AD. dendrite

AE. synapse

BC. brain

BD. soma

BE. Axon hillock

CD. terminal bouton

CE. afferent

DE. efferent

1. Processes that carry the action potential (impulse) away from the cell body. 2. The short, numerous, receptive processes of a neuron. 3. Gaps in the myelin sheath of a neuron. 4. The CNS consists of these two structures. 5. The PNS consists of the _________________ nerves and __________________ nerves. 6. Neurons that carry an impulse from a sensory receptor to the CNS. 7. Neurons that carry an impulse from the CNS to a muscle or gland are called. 8. The cell body of a neuron. 9. This will change its physiology in response to a nerve impulse and subsequent release of a neurotransmitter. Includes muscles, glands, and adipose tissue. 10. Acts as an insulator, which allows for rapid transmission of an action potential in a saltatory manner. 11. Contains synaptic vesicles that will fuse with the neuronal membrane and release a neurotransmitter. 12. The functional contact between the axon terminal of one neuron and a downstream neuronal cell body. 13. This is where the neuronal cell body and axon meet. If a local potential is enough, a total reversal of resting membrane potential will begin in this location.

EPSPs & IPSPs Complete tables below:

OPEN:

Na+

K+

Cl-

Ca2+

Na+

K+

Cl-

Ca2+

Diffuse in or out? Depol or Hyperpol? (EPSPs) (IPSPs)

INHIBIT: Trapped in or out? Depol or Hyperpol? (EPSPs) (IPSPs)

Indicate the interval(s) that best correlate with each statement. More than one letter may apply to each statement.

Select from intervals a, b, c, d, e or AB. 14. Permeability to K+ is still elevated even as the Na+ permeability has returned to normal, resting values. 15. The membrane is more permeable to K+ than to Na+, and these permeabilities are not increasing or decreasing, but are constant and unchanging. 16. The membrane is experiencing rapid changes in Na+ permeability. 17. Na+ and K+ are both at equilibrium (i.e., the electrical gradient for each ion is equal and opposite in direction to the chemical gradient.) 18. Time during which Na+ K+ pump is working. 19. The event shown above can be experienced by a) All cells of the body b) Only neurons and muscle cells

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Use these answer selections as you consider the following questions: A. EPSP

C. depolarize D. repolarize

E. adrenergic

AB. Resting memb. Pot.

B. hyperpolarization AC. IPSP

AD. upstroke AE. cholinergic

BD. Action potential

BE. downstroke

CD. threshold

BC. metabotropic DE. ionotropic

CE. All parts

20. A neurotransmitter opens a chloride ligand operated channel, the cell would have this type of post-synaptic graded potential. 21. This cell’s membrane potential would get closer to threshold (Mark “A” for True or “B” for false). 22. A neurotransmitter opens a potassium ligand operated channel, the cell would have this type of post-synaptic graded potential. 23. This cell’s membrane potential would get closer to threshold (Mark “A” for True or “B” for false). 24. A neurotransmitter binds to a metabotropic receptor and PKA is ultimately activated, which type of neurotransmitter likely bound? 25. Continuing with the previous question, the PKA phosphorylates a potassium channel and deactivates it what will happen to the membrane potential? 26. This portion of an action potential tracing represents rapidly opening sodium channels. 27. This term refers to the potential at which voltage operated sodium channels open. 28. This “steady-state” voltage value reflects that the cell membrane is more permeable to potassium than sodium. 29. This portion of an action potential tracing represents that the cell is rapidly becoming more permeable to potassium. 30. This portion of an action potential tracing reflects that potassium voltage operated channels are slow to close and as a result, the inside of the cell becomes more negative.

A. EPSP

C. depolarize

D. repolarize

E. adrenergic

AB. Resting memb. Pot.

B. hyperpolarization AC. IPSP

AD. upstroke

AE. cholinergic

BC. metabotropic

BD. Action potential

BE. downstroke

CD. threshold

CE. All parts

DE. iontotropic

31. During which parts of an action potential would the sodium/potassium ATPase be functional? 32. This term describes the temporary reversal of the resting membrane potential. 33. A postganglionic parasympathetic neuron would release this type of neurotransmitter. 34. Preganglionic neurons release this type of neurotransmitter. 35. The receptor on the post-ganglionic neuron would be of this functional classification. 36. The receptors on involuntary effector cells would be of this functional classification. 37. Receptors that activate second messengers are this functional classification. 38. True or False (mark “A” or “B”): The nAChR is an example for the previous question. 39. The mAChR is this type of functional receptor. 4

40. The opening of a cation channel that allows both Na+ and K+ to move through will cause the membrane to _____ because of the ________. A. Hyperpolarize: greater K+ electrochemical gradient as compared with Na+ B. Hyperpolarize: greater Na+ electrochemical gradient as compared with K+ C. Depolarize: greater K+ electrochemical gradient as compared with Na+ D. Depolarize: greater Na+ electrochemical gradient as compared with K+

41. The release of neurotransmitter at a chemical synapse in the central nervous system is dependent upon which of the following? A. Synthesis of acetylcholinesterase B. Hyperpolarization of the synaptic terminal C. Opening of ligand-gated ion calcium channels D. Influx of calcium into the presynaptic terminal

42. Which of the following is characteristic of the events occurring at an excitatory synapse? A. There is a massive efflux of calcium from the presynaptic terminal B. Synaptic vesicles bind to the postsynaptic membrane C. Ligand-gated potassium channels open D. Ligand-gated channels are opened to allow sodium entry into the postsynaptic neuron.

43. Which of the following electrical events is characteristic of inhibitory synaptic interactions? A. A neurotransmitter agent that selectively opens ligand-gated chloride channels is the basis for an inhibitory postsynaptic potential. B. Because the Nernst potential for chloride is about -70mV, chloride ions tend to move out of the cell along its electrochemical gradient. C. A neurotransmitter that selectively opens potassium channels will allow potassium to move into the cell D. An increase in the extra-cellular sodium concentration usually leads directly to an inhibitory postsynaptic potential. 44. Which statement concerning the generation of an action potential is correct? A. When the membrane potential at the axon hillock is below "threshold" an action potential is initiated B. The action potential is initiated in synaptic boutons C. The least number of voltage-gated sodium channels in an axon is found near the node of Ranvier D. Once an action potential is initiated, it will run its course to completion.

45. A ligand that opens a chloride channel would _____ the cell. (Chloride's electrochemical gradient is inward.) A. depolarize B. hyperpolarize C. have no effect on the voltage of

46. ____-diameter neurons conduct more rapidly because there is ____ resistance to ion diffusion. a) smaller, less c) larger, less b) smaller, more d) larger, more

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47. Some local anesthetics, like lidocaine, act on neural (axon) membranes. It makes them less permeable to sodium. From what you know about membranes, decreasing sodium permeability will a) prevent the neuron from reaching threshold b) prevent a neuron from repolarizing c) bring the neuron’s voltage closer to threshold d) not affect a neuron’s membrane potential e) none of the above are correct

48. More than one of the following may be correct. Select all correct choices: Compared to unmyelinated neurons, the AP in myelinated neurons has the following characteristic(s): a) Conduction velocity is greater. b) Over the whole neuron, fewer ions cross the membrane. So less energy is needed to restore gradients. c) Only nodal regions regenerate the AP. d) Amplitude of the action potential is greater (ie., the cell reaches a higher or lower peak voltage.)

49. Administering ACh to the axon, beyond the hillock, should result in a) an EPP d) an IPSP b) an EPSP e) none of the above c) an AP

50. A resting postsynaptic neuron is innervated by several presynaptic neurons. Three EPSP’s and four IPSP’s arrive almost simultaneously at the dendrites of the postsynaptic cell. Assuming these events are roughly equal in size, the postsynaptic cell should a) be depolarized from its resting state b) be hyperpolarized from its resting state c) be at its resting membrane potential d) cannot be determined from the information provided

51. The example above demonstrates the principle of a) frequency modulation b) amplitude modulation

c) d)

all-or-none summation

52. Which synapse would have the greatest excitatory (or inhibitory) effect? a) A synapse located far out on a dendrite b) A synapse located closest to the cell body c) It does not matter where the synapse is located

53. A stimulus acts on a receptor that then conveys this information to a sensory neuron. The stimulus is extraordinarily large. In order to communicate the intensity of the stimulus to the central nervous system, the sensory neuron will most likely a) produce an AP which peaks at value higher than + 40 mV b) conduct the AP along the membrane at a faster speed c) generate a greater number of AP’s in a given period of time d) depolarize or repolarize much more quickly e) none of the above

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Notice the picture below has electrical events labeled A through AC. "S1, S2 and S3" are stimulus 1, 2, and 3 (remember the Hodgkin and Huxley experiments when they stimulated a neuron with a "stimulating electrode").

54. 55. 56. 57. 58. 59. 60.

Sodium VGC's are opening more and are responsible for the membrane potential at this event. The event that is closest to potassium's Nernst potential. The event that represents the inactivation of sodium VGC's. Events that represent repolarization (mark all that apply). Event that represents deactivation of sodium channels and potassium channels opening more The event that shows an EPSP. The type of summation shown in the picture above, where S refers to a stimulus from one source measured in the postsynaptic membrane A) spatial B) temporal C) tetany D) fiber unit recruitment

61. In the figure above, if S2 indicated a stimulus from a different source, and S1 occurred concurrently with S2, what type of summation has been generated? A) spatial B) temporal C) tetany D) fiber unit recruitment

62. What class of metabotropic receptors activates the enzyme adenylate cyclase? A. nAChR B. mACh R C. Beta 2 only D.Beta 1, beta 2, and beta three. 63. Where are muscarinic cholinergic receptors? A. skeletal muscle cells B. parasympathetic and sympathetic postganglionic cell bodies

C. effector organs of the autonomic nervous system D. Both A and C E. A, B, C

64. What cholinergic receptors are coupled to G proteins? A. alpha-1 B. alpha-2 C. beta-2 D. nicotinic E. muscarinic

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Use the following choices to match to the statements below. Choices may be used more than once, or not at all, and there may be more than one answer.

A. Glutamate

B.

Ketamine (Special K)

C. cholinergic

D. Norepinephrine

E.

ACh

AB. IPSPs

AC. MAOIs

AD. GABA

AE. dopamine

BC. spastic

BD. PKU

BE. LSD

CD. Serotonin

CE. EPSPs

DE. Nitric Oxide

65. A low level of this neurotransmitter results in seizures and can be treated with agonists called anticonvulsants. 66. The drug Ecstasy blocks the reuptake of this “feel good” tryptophan-derived neurotransmitter and potentiates its effects. 67. Individuals with this genetic disorder lack the enzyme necessary to convert the amino acid precursor of various catecholamines and must adhere to strict dietary restrictions to prevent neurological toxicity during development. 68. This drug acts as a partial serotonin antagonist and can lead to hallucinations. 69. SSRIs are antidepressant drugs (Prozac, Paxil) that inhibit reuptake of this neurotransmitter, increasing its time spent in the synaptic cleft stimulating its receptors. 70. This neurotransmitter is the most common excitatory neurotransmitter in the central nervous system. 71. Within the ANS, this neurotransmitter is produced by preganglionic and postganglionic neurons of the parasympathetic division plus preganglionic neurons of the sympathetic division. 72. This made-on-demand lipophilic neurotransmitter requires no receptor and affects a wide variety of cell types. 73. Decreased AChE activity results in overstimulation of muscle fibers called __________ paralysis. 74. Alcohol triggers the receptor of this neurotransmitter but so do Benzodiazepines, which can be used for alcohol detox. 75. This neurotransmitter would begin an end plate potential in skeletal muscle. 76. A low level of this neurotransmitter is one of many factors linked to the psychosis (delusions, paranoia) associated with Schizophrenia. 77. Within the ANS, this neurotransmitter is only produced by postganglionic neurons of the sympathetic division. 78. This club drug blocks glutamate receptors and shows promise as a powerful antidepressant drug. 79. Mixing these drugs with sympathomimetics is like overdosing on catecholamines. 80. Carbidopa-Levodopa could be administered to a patient whose substantia nigra exhibited substantial declines in production of this catecholamine. 81. Type of neuron that contains the ChAT enzyme and produces Acetylcholine. 82. Anxiety? Try to increase IPSPs – Valium is an allosteric modulator used to promote the binding of this neurotransmitter to its receptor. 83. Binding of Glutamate would generate ___________ in a motor neuron and can result in muscle fiber contraction. 84. Binding of GABA would generate ___________ in a motor neuron and produce no muscle fiber contraction.

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Metabotropic Receptors: Major Signal Transduction Pathways Fill in the molecules for each step as described in lecture:

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3 +

Membrane Potential (mV)

50

Label each numbered period on this diagram. For each, write which gate is open / opening / closed or closing. If a gate is open, tell which direction the ion is moving.

4 0

2

5

Threshhold 70

1

1

Time (msec)

85. Generally, how far is threshold voltage from the RMP voltage? 86. How long does the AP take to occur at any point on the membrane in this cell? Mark it on the time axis. 87. What actually happens at the membrane when threshold voltage is reached? 88. Choose one. At rest (RMP), the membrane is more permeable to (sodium , potassium.) a.

how many times more permeable?

89. Choose one. At the peak of the AP, the membrane is more permeable to (sodium, potassium.) b.

how many times more permeable?

90. What is actually responsible for permeability changes in the membrane? 91. When is the Na/K ATPase working? In which direction does it pump each ion? 92. Explain why the voltage dips extra low during the hyperpolarization: 93. In the diagram, when does the Absolute refractory period (ARP) occur? Draw it in on the time axis. 94. In the diagram, when does the Relative refractory period (RRP) occur? Draw it in on the time axis. 95. What is the reason given for the ARP, RRP in terms of gated channels?

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AUTONOMIC NERVOUS SYSTEM Nervous System: Anatomical Review Use the answer choices below to match to the following descriptions. A.

B.

IMLCC

C.

Afferent, Sensory Fibers F.

D.

G.

Reflex

H.

L. Para-vertebral ganglia/ sympathetic trunk ganglia (and their postganglionic fibers)

P. Smooth muscle, cardiac muscle, glands

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.

E. Nucleus/ Nuclei

Tract

I.

J. Terminal ganglia

Nerve

Prevertebral/ collateral ganglia (and their postganglionic fibers) N. Ganglion

O.

Sympathetic Nervous System

K.

SLGC

Skeletal muscle

M.

Fiber

Somatic motor neuron/ fiber

Q. Pre-ganglionic Visceral motor cell bodies/ nerves

R.

S. Nuclei for Cranial Nerves III, VII, IX, X

Smooth muscle, cardiac muscle, glands, and adipose tissue

T. Parasympathetic nervous system

A stereotyped, automatic, involuntary respon...