Study Guide for Chapter 3

1.       What is the primary substance in the extra- and intracellular fluid (cytosol)?

2.       What feature of water makes it a very effective solvent of charged particles?

3.       What is an ion? How is an anion different from a cation?

4.       Be able to describe the composition of the bilayer membrane including the phospholipid molecules and the different types of proteins. You should be able to list or describe at least four types of membrane proteins based on what you read and what you have heard in class.

5.       Although you should look at figure (b) on page 56 of your text, do not memorize it. The figure is a diagrammatic listing of the 20 amino acids used by neurons to make proteins. Some of them you have heard of, others you haven’t. Which ones do you recognize? Chemical names that end in -ic acid (e.g., aspartic acid) are also correctly ended with -ate (e.g., aspartate).

6.       What is diffusion? How does a concentration gradient occur? What diffusion forces drive ions across a semi-permeable membrane?

7.       What is an electrical current? What two factors determine the quantity of current that flows? How much current will flow if the conductance is zero? What about when the potential difference is zero?

8.       What is the membrane potential? What is the resting potential of a typical neuron? With what device is the membrane potential measured?

9.       What is the Nernst equation? You do NOT need to memorize this equation, you do need to describe its purpose. Similarly, you should be able to explain the purpose of the Goldman equation.

10.     Be able to describe the approximate ion concentrations inside and outside the neuronal membrane. You should be able to discuss the ratios of ions outside | inside.

11.     You should be very familiar with ion channels, especially sodium, potassium, chloride, and calcium channels.

12.     What is the blood-brain barrier (bbb) and how is it formed? Where is the bbb noticeably weaker (more easily penetrated)? Why is it weaker here?

13.     What is potassium spatial buffering? For an example of the importance of maintaining proper ionic concentrations (especially potassium), read Box 3.5 on page 72 of your text.

Again, you should be able to discuss any and all of the key terms and the review questions on pages 72  and 73of your text.