Fall 1998 Biology 111 Exam #1 - Cellular Communications


There is no time limit on this test, though I have tried to design one that you should be able to complete within 2.5 hours, except for typing. You are not allowed to use your notes, old tests, the internet, or any books, nor are you allowed to discuss the test with anyone until all exams are turned in at 10:30 am on Monday September 21. EXAMS ARE DUE AT CLASS TIME ON MONDAY SEPTEMBER 21. You may use a calculator and/or ruler. The answers to the questions must be typed on a separate sheet of paper unless the question specifically says to write the answer in the space provided. If you do not write your answers in the appropriate location, I may not find them.



Please do not write or type your name on any page other than this cover page.

Staple all your pages (INCLUDING THE TEST PAGES) together when finished with the exam.


Name (please print):




Write out the full pledge and sign:







How long did this exam take you to complete (excluding typing)?




Lab Questions:

4 pts.
1) a) Tell me how you would make 150 mL of a 21% solution of NaCl if the molecular weight is 58.5. List how much of everything you would use and in what order.

b) What is the molarity of the solution you just made?

6 pts.
2) In the spaces provided, draw two graphs that compare what happens when an enzyme assay is modified (as described below) from a standard reaction which has substrate, coenzyme and cofactor in excess. Each graph should have two clearly labeled lines - normal reaction and modified reaction.

Graph 1: drastically decrease the amount of enzyme

Graph 2: drastically decrease the amount of substrate

Lecture Questions:

2 pts.
3) What makes Lamarkian evolution a good evolutionary hypothesis even though it is wrong?

3 pts.
4) What is adaptive about having organelles inside eukaryotic cells?

6 pts.
5) If this is a diagram of glucose, draw a picture of a disaccharide that has the proper linkage found in glycogen. The picture should be drawn in a blank space within your typed answers.

Do not draw it on this page. Make sure you include all the atoms that are shown in the diagram here:

6 pts.
6) a) Explain in chemical terms how enzymes can be specific for their substrates.

b) What are the consequences of enzyme specificity? Give one biological example.

12 pts.
7) Describe three examples that we have studied which are examples of allosteric modulation and three examples that are covalent modulation. In each of your six examples, tell me what molecule did the modulating, what was modulated, and what change in function resulted from this modulation.

3 pts.
8) Get on the WWW and enter this URL: http://bio.davidson.edu/biology/macampbell/111test1.gif

What is the name of this molecule?

14 pts.
9) a) In OUTLINE FORMAT, describe all the steps that happen in normal muscle contraction, AFTER calcium has entered a muscle's cytoplasm.

b) In outline format, describe what must happen in order for a muscle to relax.

9 pts.
10) a) List three proteins that are involved in exocytosis of acetylcholine. You may not include "unknown factors" as one of your answers.

b) What is the function of each of these proteins in secretion?

6 pts.
11) a) Name a second messenger other than cAMP, or calcium.

b) Describe how it is made and what happens next when this second messenger is made.

12 pts.
12) a) What is the difference between an action potential and a membrane potential?

b) What two proteins facilitate the beginning of an action potential?

c) What two events cause the membrane potential to hyperpolarize?

d) What protein reestablishes the resting membrane potential after hyperpolarization?

9 pts.
13) In OUTLINE FORMAT, describe the six-step mechanism by which calcium is pumped out of the cytoplasm.

4 pts.
14) If nerve gas works by binding to and inactivating acetylcholinesterase, how would a person's body respond to the poison?

4 pts.
15) a) How could you determine what the molecular weight of the SER calcium pump is?

b) How could you determine where within a cell a new protein was located?

Go to the Answer Key

Reutrn to the Biology 111 Page.