6. The first step in metabolism of ethanol in humans is the oxidation of ethanol to acetyldehyde by the enzyme alcohol dehydrogenase (ADH). At 298 K and pH=7.0, ethanol is incubated with ADH and the concentration of ethanol and acetyldehydee is measured over time.
a. Using the results above, calculate the standard free energy change (ΔGº’) for this reaction. Explain your calculations.
The standard free energy change can be expressed through the formula ΔGº’=-R(gas constant) T(temp in Kelvin) lnK’eq. K’eq is equal to the products of a reaction over the reactants of a reaction, or Products/Reactants. So, K equilibrium of this question would be 3.5 (Acetaldehyde)/6512.3 (Ethanol) because this is where equilibrium is reached. So the K’eq=5.37x10-4. So to determine the ΔGº’, -R= -1.987 cal/mol K, T=298 K, and lnK’eq=-7.53. This would make the equation= -1.987(298)ln(7.53). ΔGº’ comes out to equal ~-1195.
b. After dinner and a few drinks, the concentration of ethanol in a cell is measured to be 3412 mol/L and the concentration of acetaldehyde is measured to be 1.4 mol/L. Calculate ΔG’ and explain …show more content…
This is a form of fermentation and occurs because an oxygen supply is not readily available. Fermentation occurs after glycolysis after pyruvate has been formed. In the pathway of ethanol metabolism, first, PDC (Pyruvate Decarboxylase) must catalyze a reaction in which Carbon Dioxide will be released, and pyruvate is converted to Acetaldehyde. Then, Alcohol Dehydrogenase comes in and reduces NADH+H+ to NAD+, and Acetaldehyde is converted into Ethanol. The body converts Pyruvate to Ethanol because not enough oxygen is in supply to go through Aerobic Respiration; therefore the body must obtain energy from somewhere. This fermentation process regenerates NAD+ which powers glycolysis. From glycolysis, the body gains about 2 molecules of ATP, so not a lot of energy comes from the consumption of
a. Using the results above, calculate the standard free energy change (ΔGº’) for this reaction. Explain your calculations.
The standard free energy change can be expressed through the formula ΔGº’=-R(gas constant) T(temp in Kelvin) lnK’eq. K’eq is equal to the products of a reaction over the reactants of a reaction, or Products/Reactants. So, K equilibrium of this question would be 3.5 (Acetaldehyde)/6512.3 (Ethanol) because this is where equilibrium is reached. So the K’eq=5.37x10-4. So to determine the ΔGº’, -R= -1.987 cal/mol K, T=298 K, and lnK’eq=-7.53. This would make the equation= -1.987(298)ln(7.53). ΔGº’ comes out to equal ~-1195.
b. After dinner and a few drinks, the concentration of ethanol in a cell is measured to be 3412 mol/L and the concentration of acetaldehyde is measured to be 1.4 mol/L. Calculate ΔG’ and explain …show more content…
This is a form of fermentation and occurs because an oxygen supply is not readily available. Fermentation occurs after glycolysis after pyruvate has been formed. In the pathway of ethanol metabolism, first, PDC (Pyruvate Decarboxylase) must catalyze a reaction in which Carbon Dioxide will be released, and pyruvate is converted to Acetaldehyde. Then, Alcohol Dehydrogenase comes in and reduces NADH+H+ to NAD+, and Acetaldehyde is converted into Ethanol. The body converts Pyruvate to Ethanol because not enough oxygen is in supply to go through Aerobic Respiration; therefore the body must obtain energy from somewhere. This fermentation process regenerates NAD+ which powers glycolysis. From glycolysis, the body gains about 2 molecules of ATP, so not a lot of energy comes from the consumption of