Enzymatic Analysis of Yeast Alcohol Dehydrogenase Lab Report

Enzymatic Analysis of Yeast Alcohol Dehydrogenase - Lab Report Example A similar experimental design was used to analyze the effect of prior presence of varying concentrations of ethanol in the reaction mixture to evaluate its effect on the recovery of MTT formazan, thereby indicating the effect of alcohol on aldehyde dehydrogenase activity. Ethanol presence enhanced the alcohol dehydrogenase activity at all concentrations. A Vmax value of 0.0224Â µmol/min and Km value of 1.171 M were obtained. Alcohol dehydrogenase is the main enzyme involved in fermentation of carbohydrates for the commercial and industrial production of alcohol. It is derived from yeast, which is added to carbohydrates to induce anaerobic fermentation. Chemically, Alcohol dehydrogenase is a homotetrameric enzyme of approximately 150 kDA size which catalyses the reversible oxidation of alcohols. It is responsible for converting ethanal to ethanol and other alcohols during fermentation. Fermentation is the process in which glucose, a major constituent of all carbohydrates, undergoes glycolysis under anaerobic conditions with the resultant production of alcohol. The reaction is characterized by the regeneration of oxidized nicotinamide dinucleotide (NAD+), which is essential for maintenance of glycolysis under anaerobic conditions with resultant seizure of mitochondrial respiration. Estimation of NAD+ spectrophotometrically can therefore serve as an important method of estimating and monitoring the oxidati on of ethanol. Two experiments were designed for the purpose. In the first experiment, the optimal conditions necessary for the catalytic activity of yeast dehydrogenase (yADH) were studied by first preparing yeast extract under identical conditions and then subjecting these extracts to variable factors like dilution, time, pH and temperature. The production of NADH was measured indirectly by following the reduction of 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide