Action Potential Web Quest
Part 1 – Neurons
Go to http://health.howstuffworks.com/brain1.htm
Read the text and answer the following questions.
1. What is a neuron? ______
2. Draw a neuron below and label the parts in the box below.
Part 2 – The Sodium/Potassium Pump
Go to:
http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/animations/ion_pump/ionpump.html
View the animation
1. How many positive sodium ions are being pumped out? ______
2. How many positive potassium ions are being pumped in? ______
3. Since the numbers are different could this cause an imbalance of charge on either side of the membrane? ______
4. What molecule is providing the energy for this ion transport? ______
5. What is the process called when particles are being transported against the concentration gradient across a membrane?
______.
Part 3 – The Nerve impulse & Synapse
Go to http://www.bris.ac.uk/synaptic/public/basics_ch1_2.html
1. Neurons maintain different concentrations of certain ions across their cell membranes. What ion is in high concentration
outside the neuron? ______
2. Which ion is in high concentration inside the neuron? ______
3. What specialized protein exists in the neural cell membrane? ______
4. What is its function? ______
5. Under resting conditions which ion leaks more, the sodium leaking inward or the potassium leaking outward? ______
6. The result of the leaks makes the outside of the cell charged ______and the inside of the cell charged ______. The cell is said to be ______.
7. Since sodium is in high concentration outside of the cell what happens if the sodium channel opens in the membrane? Which way does the sodium move? ______.
8. This makes the neuron momentarily ______charged. The cell is said to be ______.
9. This switch in membrane potential is the ______.
10. View the animation to see how the action potential moves down the length of the cell (in one direction). Summarize what’s
happening.
______
11. What is the speed of an action potential directly related to? ______
12. What type of axon results in fast transmission rates? ______
13. What substance allows for rapid action potential? ______
14. What produces myelin in the PNS? ______CNS? ______
15. Where does an action potential take place on a myelinated neuron? ______
16. Why does an action potential happen faster on a myelinated neuron than an unmelinated neuron? ______
______
______
17. What does the disease Multiple Sclerosis have to do with all this?
______
Go to http://www.blackwellpublishing.com/matthews/actionp.html
View this animation. It shows the action potential moving in one direction along the neuron’s axon.
1. What is happening to the charge on the outside and inside of the cell as the action potential moves? ______.
Go To Website – http://psych.hanover.edu/Krantz/neurotut.html
Click on > Review of Physical Factors involved in the Action Potential.
Read – Diffusion
1. Give the definition of diffusion.______
> Click on Figure 1 Diagram.
2. What is the ultimate goal of diffusion? ______
> Click on Right Arrow - Diffusion and the Axon
3. Is the inside of the axon more positive or negative during the resting potential? ______
4. What do the colored bars represent? ______Colored circles? ______
5. During the resting phase the concentration of ______is greater outside and the concentration of ______is greater inside.
> Click on the ion channels and observe Figure 3a
> Click on Left arrow
6. Answer Question 1. ______
Click on > Right Arrow - Electrical Charge and Attraction
7. Define Ion. ______
8. Opposite charges do what to each other? ______
>Click on Right Arrow
9. Like charges do what to each other?______
Click on > Right Arrow - Voltage and the Axon
10. During the resting potential the axon has a ______to ______voltage comparing the inside to the outside.
11. So what effect will the voltage difference have on the Na+ ions when the Na+ channels first open? ______
(write and click on the correct answer)
Click on > Back Button then Click on > Right Arrow - Depolarization
12. Describe the axon at the end of the depolarization phase. ______
13. At the end of the depolarization phase, what is the tendency for movement of a sodium ion at the mouth of a sodium channel?
______
Click on > Right Arrow - Repolarization
14. Describe the events of repolarization. ______
______
Click on > Right Arrow – The Action Potential
15. Give a brief summary of the overall occurring events involved in the Action Potential. ______
______
*********Take the short QUIZ by clicking on Quiz in the left margin. ********
Name______Date______Period______A.T. LAB
Go to Website: http://faculty.washington.edu/chudler/introb.html#tn
Ø Click on Neuron
Ø Click on Neurotransmitters and Neuroactive Peptides
Click on the word “Synapse”
1. What is the function of the dendrites? ______
2. What is the function of the axon? ______
3. What is the synapse? ______
4. What three things does a synapse consist of?
1. ______
2. ______
3. ______
Read Electrical Trigger
5. Give a brief description of what happens. ______
______
______
______
______
______
6. Can a neuron produce and release more than one type of neuron? ______
Read Diffusion of Neurotransmitters across a Synaptic Cleft.
7. Give a brief description of what happens. ______
______
______
______
______
______
______
8. What can change the properties of neurotransmitter release? ______
9. What are neurotoxins? ______
10. Give 3 examples and the effect of them.
1. ______
2. ______
3. ______
11. In 2009 how old did the word “synapse” turn? ______
Go back to Neurotransmitters and Neuroactive Peptide page (the original page you started on)
Read Discovery
12. Who discovered the first neurotransmitter? ______
13. What animal did he use in his experiments? ______
14. What is the name of the neurotransmitter that was discovered? ______
Read Neurotransmitter Criteria and give a brief description of the six criteria.
1. ______
2. ______
3. ______
4. ______
5. ______
6. ______
Read Types and Synthesis and list the six different small molecule neurotransmitters.
1. ______2. ______3. ______
4. ______5. ______6. ______
Read Transport and Release of Neurotransmitters
15. Where are the neurotransmitters made?______
16. Once a neurotransmitter is made where does it go within the neuron? ______
17. What is the function of the vesicles? ______
18. Can neurotransmitters bond to any receptor on the postsynaptic membrane? ______
19. What are the four mechanisms that can stop the action of a neurotransmitter? Briefly describe each one.
1. ______
2. ______
3. ______
4. ______
20. The three neurotransmitters that are inactivated by reuptake are ______, ______, ______
Read Did you Know?
21. When did the idea for the heart experiment first occur to Otto Loewi? ______
22. When did he conclusively prove the chemical transmission of nerve impulses? ______
Go to www.factmonster.com Using the encyclopedia define the following terms:
Ø Acetylcholine - ______
Ø Serotonin - ______
Ø Norepinephrine - ______
Ø Dopamine - ______
Ø Gamma – aminobutyric acid (GABA) - ______
Ø Endorphin - ______