Biochem I test III Take Home. DUE when taking the final test!
Name _______________________________
1) Using provided publications from the website and other information (both general and published
documents) answer the following:
 What is a statin drug and what is the metabolic PATHWAY targeted by most statin drugs? (2 points)
 What is the enzyme, reactant and product inhibited by most statins and what is the mechanism of
action on the enzyme? (5 points)
 How (not what) does statins impact cholesterol levels? (2 points)
 Statins have other off target effects. Pick a off target, off label, non-cholesterol effect of statin
and explain how the lipid involved impacts that issue. Try to avoid everyone doing the same
thing. In depth, mechanism focused answers will earn maximum points. Simple descriptive
answers will not. (6 points)
2) (10 points) You measure the initial velocity of an enzyme in the absence and presence of an
inhibitor. In each case the inhibitor is at 10 µM. Show the data of the primary data for all three
cases and the lineweaver-burk plot.
Calculate the Km and Vmax for each case both graphically and mathematically. Determine
the mechanism for each inhibitor and where they will interact on the enzyme.
[S] mM
0.33
0.50
1.00
2.00
5.00
Initial Velocity (µmole/ml min)
Enzyme
Enzyme
Enzyme
alone
+ inhibitor 1
+ inhibitor 2
1.65
1.05
0.79
2.13
1.43
1.02
2.99
2.22
1.43
3.72
3.08
1.79
4.00
3.80
2.00
3) (10 points) Relate the concepts of feedback and feed forward inhibition as they relate to the
kinetic mechanisms. Show both a theoretical metabolic pathway for the pathways and the
resulting kinetics. (Not one included in the notes from class).
4) (5 points) Describe the sequential reaction for an enzyme with two substrates and two products.
This enzyme binds either substrate in any order but releases one substrate before the second. Draw
and name the W.W. Cleland notation for this enzyme’s reaction.