The following question focuses on how the parameters regulating enzyme function might change, and how these might appear graphically on a Michaelis-Menten plot and a Lineweaver-Burke plot. Carbonic anhydrase is an enzyme that will convert CO2 and water into HCO3. CO2 + H20 > H+ + HCO3 There are many different isoforms of this enzyme. (see for instance http://en.wikipedia.org/wiki/Carbonic_anhydrase 1 Assume that one variant has a Km of 10 µM and a different variant has a Km of 100 μM. Draw on the same graph a typical Michaelis-Menton plot showing the alteration in the rate of carbonic anhydrase as the CO2 level is varied for the two different variants of enzyme, assuming the concentration of the enzyme (10 mM) in the test tube is kept constant. Assume that you have equal amounts of the two different variants of carbonic anhydrase in a number of test tubes and that the Vmax for both enzymes are the same. Be sure to label the axes 2. For the same conditions as above, draw a Lineweaver- Burk plot for both enzymes on one graph. 3. Morphine is a non-competitive inhibitor of carbonic anhydrase. Draw on the same Lineweaver-Burke plot as above a graph showing the effect of a concentration of morphine that inhibits the first enzyme such that it reduces the Vmax to ½ its maximal value. Make sure to put in sample data points. 4. Imidazol is a competitive inhibitor of carbonic anhydrase. It is effective at an alkaline (high) pH; in lower (more acidic) pH, it no longer inhibits the enzyme. Draw on a separate graph a Lineweaver-Burke plot for the effects of this compound at high pH and low pH. Be sure to label the axes and put in sample data points. 1

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter3: The Plasma Membrane And Membrane Potential

Section: Chapter Questions

Problem 1SQE: Using the Nernst equation, calculate the equilibrium potential for Ca2 and for C1 from the following...