From image A above, knowing the criteria of a resting membrane potential, what are the purple (+) charged balls? What are the orange (+) charged balls? What is the significance of their movement in/out of the neuron membrane? In addition, what do the purple doors and orange doors represent? Are they chemically-gated or voltage gated? How can you tell?

Bonus Assignment: Neuron Action Potential (5 pts)

 *Use another color for your answers*

 The process of an action potential propagation along a neuron’s axon was discussed in lecture this week.  The diagram below illustrates each step of the process from A to F.

A      B    C

D        E     F

1. Describe the image:

What is happening at each step of the image.  Be sure to note what is happening at each neuron membrane potential, which ion channels are open/closed, and the direction of ion movement.

1. (-70 mV)
2. (-60 mV)
3. (+10 mV)
4. (+30 mV
5. (-90 mV)
6. (-70 mV)

Label the neuron action potential graph below with corresponding A-F.

1. Explain the plausible meanings and/or purposes: From image A above, knowing the criteria of a resting membrane potential, what are the purple (+) charged balls?  What are the orange (+) charged balls?  What is the significance of their movement in/out of the neuron membrane?  In addition, what do the purple doors and orange doors represent?  Are they chemically-gated or voltage gated?  How can you tell?

1. Discuss the potential consequences and/or implications of the image’s meaning:From what you have discussed in the descriptions above, why is the presence of a Na+/K+ pump critical for a neuron?  What happens when a person dies, cellular respiration stops, ATP production stops, and thus, the Na+/K+ pump stops working?  Explain your answer.