Reference no: EM131126969

Enzyme kinetic problems

1. You measure the initial rate of an enzyme reaction as a function of substrate concentration in the presence and absence of an inhibitor.  The following data was obtained:

[S] (mM)	Vo (-) Inhibitor (mM/min)	Vo (+) Inhibitor (mM/min)
0.0001	33	17
0.0002	50	29
0.0005	71	50
0.001	83	67
0.002	91	80

Please submit calculations and graph for full credit!

Note:  You are required to use Excel to generate the Lineweaver-Burk plot

(a) Create a Lineweaver-Burk plot (inhibited and uninhibited should be on the same plot!)

(b) Calculate the V_max in the presence and absence of the inhibitor.  Show your calculation.

(c) Calculate the K_m in the presence and absence of the inhibitor. Show your calculation

(d) What type of inhibitor is this?  How do you know (clearly explain)?

2. Prostaglandins are derivatives of fatty acids that are responsible for producing fever, inflammation and its associated pain. They are synthesized from a 20 carbon fatty acid, arachidonic acid (AA), in a reaction catalyzed by prostaglandin endoperoxide synthase. The product of the reaction, PGG_2, can then be used to synthesize other prostaglandins.  Ibuprofen is an inhibitor of prostaglandin endoperoxide synthase, thus it used to relieve pain and inflammation.

The following data was generated in the laboratory:

Arachidonic Acid(mM)	Rate of formation of PGG2 (mM/min)	Rate of formation of PGG2 with 10 mg/ml ibuprofen(mM/min)
0.5	23.5	16.67
1.0	32.2	25.25
1.5	36.9	30.49
2.5	41.8	37.04
3.5	44.0	38.91

Please submit calculations and graph for full credit!

Note:  You are required to use Excel to generate the Lineweaver-Burk plot

(a) Create a Lineweaver-Burk plot (inhibited and uninhibited should be on the same plot!)

(b) Calculate V_max and K_m in absence of the inhibitor. Show your calculations.

(c) Calculate the V_max  and  K_m in the presence of the inhibitor.  Show your calculations.  What type of inhibitor is ibuprofen?  Briefly explain your answer.