Biology 111: Unit 1                                                    February 2002

The review is due Friday February 15th before 9:30am.

This is a closed-book, closed-note review. Once you have read any question your review period has begun. There is no time limit for taking the review. It was designed to be completed in 2 hours.

Be sure to follow all instructions. The questions are yours to keep. This page must be the first page of your answer packet. Fill out the information at the bottom of this sheet and attach this page to the ones containing your answers. The top of each additional page in the packet should contain only your initials and the page number. All answers must be typed and in complete sentences unless specifically indicated otherwise. Any accompanying graphs or figures may be hand-drawn. You may use a (non-pre-programmed) calculator but all calculations must be included in order to receive full credit. Calculations do not need to be in sentence format.

Brevity is encouraged but be sure to completely answer the question asked. If a word number maximum is indicated be sure to include the word count of your answer (MS Word will determine this for you under the tools menu). 

Any questions about the review should be directed to me at kabernd@davidson.edu, x2889 (o), or XXXXXX (h). Any calls to my home must occur before 9:00pm.

Name: ____________________________________

            (print)

Signature: ­­­­­­­_________________________________

My signature indicates that I have completed this review following the Honor Code.

This review was completed in ________hours

I attended ____ Dr. Cho’s (bioarcheology)  ___ A. Udall (Environmental Action)

___ Biology ‘Major Decisions’   ___ Darwin’s Birthday party

The questions on this review refer to the scenario provided. Questions A-X (100 points)

As a world-renowned scientist you travel to the jungle and discover two groups of gorillas inhabiting adjacent mountains. One group (the calm gorillas, or CGs) exhibits ‘typical’ gorilla behavior where much of their time is spent eating leaves and berries and grooming other CGs. In the other group, the jumpy gorillas (or JGs) are the same stature but lower body weight and are constantly agitated. You think that the behavioral differences are due to overactive adrenal glands causing a constant stress response.

To test your hypothesis you obtain blood samples from one CG and one JG. One blood samples is taken when the gorilla is sleeping and another is take while the gorilla is watching a movie of a python. (Gorillas are afraid of pythons and can’t tell the difference between movies and real life)

You decide to compare blood glucose levels in order to test your hypothesis. To test your equipment you want to perform blood glucose analysis on samples containing known amounts of glucose. The lab is equipped with chemical stocks, balances, water, graduated cylinders, beakers, and, amazingly, all of the equipment you would need to perform the procedures you learned about in your Molecules, Genes and Cells class back at Davidson College. The chemical stocks include 250mg of glucose (MW 180.16). Your lab technician is very eager but not very clever and so you must provide detailed instructions on how to make the glucose solutions.

1. Provide instructions for making 5ml of an 8% w/v solution of glucose. (4pt)
2. What type of molecule is glucose? (2pt)

After testing your equipment and preparing a standard curve you collect the following data from your gorilla blood samples:

Blood Glucose Levels (mg/ml)

3. Why was it important to include samples from the CG in this experiment? (3pt)
4. Briefly explain the biological processes that caused blood glucose levels to increase after each gorilla was exposed to the python movie. (Fifty word maximum) (5pt)
5. Explain how the data in the table supports or refutes the hypothesis you stated in the first paragraph. Be sure to address each piece of data. (200word max) (6pt)
6. What is the molarity (in mM) of glucose in the blood of the JG watching the python? (3pt)

You are discussing the blood glucose analysis with a colleague. She is interested in your behavioral observations but does not agree with your molecular approach. She strongly suggests that blood glucose levels are not the best way to determine if the adrenal gland is overactive. She provides a very convincing argument.

7. What is her argument? (What are the failings of monitoring blood glucose levels as a way of following adrenal gland activity?) (150 word maximum) (4pt)
8. What is the name of the storage form of glucose and what interactions directly lead to its release from this storage form? (5 pt)
9. What compound would be a better indicator of overactive adrenal function and why is it better? (4pt)

You excitedly focus your attention on studying the molecule you named in part I.

10. What is an absorbance maximum? (3pt)
11. How would you determine the absorbance maximum of the compound that you named in part I? (Assume that you, conveniently, have a pure stock of the substance within your lab) (4pt)

Another line of research in your lab is studying a newly identified gorilla hormone that you call ‘primatin’. Primatin is sometimes found in very low levels in the blood and appears to be part of the stress response in gorillas. You discover that primatin is a short protein secreted from cells via a mechanism that is amazingly similar to the release of acetylcholine in the neuron.

12. What organelles does primatin pass through as it moves through the cell to be secreted? (3pt)
13. You want to study primatin-containing vesicles. What method could you use to isolate a sample of them? (Be sure to explain your reasons for choosing this method) (4pt)
14. Why is primatin ‘trapped’ within the vesicles? Explain the characteristics of the vesicle and of primatin that keep the hormone confined to that space. (200 word max) (6pt)
15. Your lab has seen many many similarities between primatin secretion and acetylcholine secretion. Given all of these similarities form a hypothesis for the mechanism used to trigger primatin’s secretion from the cell. (3pt)
16. What are the makings of a good hypothesis? Explain how your hypothesis in ‘0’ follows your ‘guidelines for good hypotheses’. (200 word max) (7pt)
17. Describe the type of transport that maintains membrane potential in all living cells. (Note that ‘type’ is a general term.) (3pt)

Bonus: Draw two amino acids bonded to each other. (1pt for generalized structure, 2.5pt if specific amino acids are drawn) Circle and provide the name of the bond that links them. (1pt)

Your lab technician wants to study the enzymatic reaction shown below.

cAMP phosphodiesterase

                   cAMP                                                  AMP

18. What is an enzyme? (3pt)
19. What type of molecule is the product? (2pt)
20. If you compared enzymatic activity in the liver cells of a sleeping gorilla with activity in the liver cells of a gorilla watching the python movie would you expect to see an increase/ decrease/ or no change in the rate of this reaction? (Explain your answer) (5pt)
21. The reaction diagrammed is very important to the stress response in cardiac muscle. What role does the reaction play in cardiac cells response and how is this same role fulfilled during the propagation of an action potential in a neuron? (200 word max) (7pt)

It is a very cold year and both gorilla groups come down from their mountain into a lush and protected valley. While they share space a male JG and female CG mate. Your technician is perplexed when the female CG becomes pregnant and wants to know how this could happen. After determining that he does know the basics of sexual reproduction, you explain the molecular mechanism for determining suitable reproductive partners.

22. In molecular terms, how is the CG able to be impregnated by the JG? (4pt)
23. Why was the development of sexual reproduction important to the evolution of life? (4pt)
24. Compare and contrast the role of trimeric G proteins in fertilization with their role in the stress response in cardiac muscles. (200 word max) (6pt)