Malate dehydrogenase is an enzyme that converts malate to oxaloacetate inthe last stage of the TCA Cycle (citric acid cycle/Krebs cyde), represented bythe following equation:NAD+MalateOxaloacetateNADHA group of students carried out an experiment to determine the optimumtemperature for the activity of a commercially produced malate dehydrogenase(from yeast) at several different temperatures. A series of test tubes was setup containing 2.0 cm of phosphate buffer with a pH of 7.5, 0.1 cm? of NADH,0.1 cm of malate dehydrogenase and 0.7 cm3 of water. The tubes wereincubated in water baths at the various temperatures for 5 minutes. At certaintime intervals each tube was placed in a colorimeter, set at an absorbancevalue of 1.0. The reaction was then started by adding 0.1 cm? of oxaloaceticacid to the tube. Enzyme activity was measured by following the decrease inabsorbance for 120 seconds. The experiment was repeated to give duplicateresults. Enzyme activity was then calculated as umoles per mg of (enzyme)protein. The results are shown in Table 1 below:Table 1: Results to show the activity of malate dehydrogenase at varioustemperatures.Enzyme activity (umoles per mg protein)Temp.(°C)Test 2 (Duplicatetest)Average (totwo decimalpoints0.20Test 10.0010.00.2013.00.2012.712.9050.290.020.052.051.1030.091.390.7040.082.779.381.0050.041.540.040.8017.29.9060.016.016.6070.010.09.95a)On the graph paper provided, plot the data in a suitable form.b)Briefly explain the effect of temperature on malate dehydrogenaseactivity.c)What is the optimum temperature for the activity of malatedehydrogenase (calculated from your graph)?

Malate dehydrogenase carries out a reversible reaction between malate and oxaloacetate. The Malate…

Malate dehydrogenase is an enzyme that converts malate to oxaloacetate in the last stage of the TCA Cycle (citric acid cycle/Krebs cydle), represented by the following equation: NAD+ Malate Oxaloacetate NADH A group of students carried out an experiment to determine the optimum temperature for the activity of a commercially produced malate dehydrogenase (from yeast) at several different temperatures. A series of test tubes was set up containing 2.0 cm of phosphate buffer with a pH of 7.5, 0.1 cm of NADH, 0.1 cm of malate dehydrogenase and 0.7 cm of water. The tubes were incubated in water baths at the various temperatures for 5 minutes. At certain time intervals each tube was placed in a colorimeter, set at an absorbance value of 1.0. The reaction was then started by adding 0.1 cm of oxaloacetic

Malate dehydrogenase is an enzyme that converts malate to oxaloacetate in the last stage of the TCA Cycle (citric acid cycle/Krebs cydle), represented by the following equation: NAD+ Malate Oxaloacetate NADH A group of students carried out an experiment to determine the optimum temperature for the activity of a commercially produced malate dehydrogenase (from yeast) at several different temperatures. A series of test tubes was set up containing 2.0 cm of phosphate buffer with a pH of 7.5, 0.1 cm of NADH, 0.1 cm of malate dehydrogenase and 0.7 cm of water. The tubes were incubated in water baths at the various temperatures for 5 minutes. At certain time intervals each tube was placed in a colorimeter, set at an absorbance value of 1.0. The reaction was then started by adding 0.1 cm of oxaloacetic

Biochemistry

6th Edition

ISBN:9781305577206

Author:Reginald H. Garrett, Charles M. Grisham

Publisher:Reginald H. Garrett, Charles M. Grisham

Chapter18: Glycolysis

Section: Chapter Questions

Problem 18P: Distinguishing the Mechanisms of Class I and Class I Aldolases Fructose bisphosphate aldolase in...

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Based on your knowledge of the structure of NAD+ and an assumption that coenzyme dissociation is the rate limiting step of the alcohol dehydrogenase mechanism, hypothesize why a N249W mutation at the coenzyme binding site would increase the rate of catalysis.
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Ethanol as a Source of Metabolic Energy (Integrates with Chapters 19 and 20.) Acetate produced in ethanol metabolism can be transformed into acetyl-COA by the acetyl thiokinase reaction: Acetate+ATP+CoASHacetyleCoA+AMP+PPiAcetyle-CoA then can enter the citric acid cycle and undergo oxidation to 2 CO2by this route, assuming oxidative phosphorylation is part of the process? (Assume all reactions prior to acetyl-CoA entering the citric acid cycle occur outside the mitochondrion). Per carbon atom, which is a better metabolic fuel, ethanol or glucose? That is, how many ATP equivalents per carbon atom are generated by combustion of glucose versus ethanol to CO2?
Each of the following citric acid cycle enzymes catalyzes electron transfer to NADH/FADH2 except A) isocitrate dehydrogenase. B) α-ketoglutarate dehydrogenase. C) succinyl CoA synthetase. D) succinate dehydrogenase. E) malate dehydrogenase.
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