Zoology 211; Fall, 1996

W. Higgins, Round I 

Circle your laboratory meeting time: MON TUES WED THUR FRI
OR morn morn morn morn morn
NO LAB  aftern aftern aftern aftern aftern
  nite nite nite 

DIRECTIONS:

1.  PRINT YOUR NAME on each and every page of the examination NOW! Remember to answer the questions in pen if you wish the right to a regrade request.
2.  You must confine your answers to the spaces provided. No exceptions. We don't have time to hunt.
3.  You must remain seated until we have collected the examinations. We will make the first collection from those who are finished and wish to leave at 12:40 PM. Everyone else will remain seated until 12:50 PM.
4.  Answer the question that is asked. Be specific and concise!
5.  Read the first in this year's series of deathless quotes ad begin:


 

"Knowledge is to know both what one knows and what one does not know."

- Confucius

SCOREBOARD


 

PAGE

HIGGINS POINTS

VISITOR'S POINTS

2

26 

____________

3

26

____________

4

20 

____________

5

15 

____________

6

13 

____________

TOTALS 

100 points            vs 

____________

1.

On the graph ON THE LEFT, Dr. Know-It-All has graciously plotted the results of an assay for the reaction:                                                      L + M + ATP ---> N + ADP + Pi that is catalyzed by the enzyme Qzyptrk.
 
 

a.   Which region of the graph (A, B, or C) represents the following situations:
 

- Active site of Qzyptrk is occupied by substrate m- Includes the point (Km, Vmax/2):ost of the time:  __________
- Active site of Qzyptrk is free or unoccupied most of the time: __________
- Reaction velocity is limited mainly by the number of Qzyptrk molecules:  __________
- Reaction velocity is limited mainly by the [L] and [M]:  __________

  b.   Label the Km and Vmax on the graph on the LEFT.
 
 

c.   Use the axes on the RIGHT and construct the Lineweaver-Burk plot for this reaction and write the equation for this line here:

      ______________________________________________
 

d.   The value for the slope of this plot is given by:

      __________________________________
 
 

e.   The value for the y intercept is given by:               __________________
 

      The value for the x intercept is given by:               __________________
 

f.    On BOTH graphs plot the results of another assay of Qzyptrk's activity conducted in the presence of Schmaltz, an allosteric inhibitor of Qzyptrk.
 
 

g.   Describe the experiment that was done to yield the graph on the LEFT (25 words or less):
 

h.   What can you assume about the value of *H?       _________________________________
 

i.    What can you assume about the value of *S?       _________________________________
 
j.    IF the value for Keq were = 1, then *G would = __________________.
 
 

2.    As the goldfish in my grandmother's pond adjusted from summer's heat to winter's cold, what happened to (increase, decrease, or didn't change):
 

  a.  The length of the fatty acid side chains in the membrane phospholipids: __________
  b. The degree of unsaturation of the fatty acid side chains in the membrane phospholipids: __________
  c. The transition temperature between the liquid and solid state of the membrane phospholipids __________
  d. The number of ionic bonds formed among phospholipid 'R' groups on the polar heads: __________

    Explain briefly how these changes affect BOTH of the forces that hold the nonpolar lipid portion of the plasma membranes together:                      

    ____________________________________________________________________________

    ____________________________________________________________________________

    ____________________________________________________________________________
 
    ____________________________________________________________________________

    ____________________________________________________________________________

 

3.

a.   Draw the amino acid serine (R group = CH2-OH) linked by a peptide bond to alanine (R group = CH3):
 
 

 
 
 

b.   Characterize the nature of the amino acid serine:   _________________________________   

4.

a.   LIST the starting materials and end products of the Calvin Cycle (Dark reaction of photosynthesis). Include the correct numbers of each:                        

STARTING MATERIALS  END PRODUCTS     
_______________________________  _______________________________ 
_______________________________  _______________________________ 
_______________________________  _______________________________ 
_______________________________  _______________________________ 
_______________________________ 

 

b.   All plants, but especially those in tropical climates, face a major problem within this scheme of carbon fixation. What is the problem?

    __________________________________________________________________________

    __________________________________________________________________________

    __________________________________________________________________________

    __________________________________________________________________________

    __________________________________________________________________________
 
 

5.

a.   During times of insufficient oxygen, i.e., during prolonged strenuous exercise, some pyruvate is not oxidized, but given another metabolic fate. What happens to this pyruvate and for what reason is this important?
 
    __________________________________________________________________________

    __________________________________________________________________________

    __________________________________________________________________________    

6.  Describe the chemiosmotic formation of ATP. NO PICTURES, PLEASE!
 


 

7.

a.   In the thylakoid membrane below, draw the important components of the light reaction of photosynthesis. Be sure to label the STROMA and the THYLAKOID LUMEN and trace the origin, pathway and fate of the electrons.
 

 
 


 
 

 
 
 

b.   List the sources of the proton motive force or proton gradient you drew above:
 
      1. ___________________________________________________________

      2. ___________________________________________________________

      3. ___________________________________________________________
 
 

8.   Answer each of the following with (I)NCREASE, (D)ECREASE, OR NO CHANGE (NC):  
 

a.      As the fluidity of a membrane increases, the biological activity of that membrane  ________________
b.     As the amount of an enzyme added to a reaction is increased, the Keq of that reaction ________________
c.     As the amount of an enzyme added to a reaction is increased, the absolute value of the *G of that reaction ________________
d.     As the atmospheric concentration of CO2 is decreased, the rate of the Calvin Cycle reaction ________________
e.     As the rate of the Krebs Cycle reaction increases, the intracellular           [CO2] ________________

 

9.     a. In glycolysis, how many electrons are removed from glucose? ________________
        b. In the oxidation of CH3(CH2)14COO-, how many molecules of Acetyl Coenzyme A are formed? ________________
        c. Give ONE amino acid that serves as an attachment point for carbohydrates on glycoproteins:  ________________
        d.. List three ways enzyme activity may be regulated (do not include just the general term 'inhibition')  ________________


 
 

10. Why do you require oxygen? (Please be specific!)

    __________________________________________________________________________