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Lactic acid fermentation. (a) Write a balanced equation for the conversion of gl

ID: 1064882 • Letter: L

Question

Lactic acid fermentation. (a) Write a balanced equation for the conversion of glucose into lactate. (b) Calculate the standard free-energy change of this reaction by using the data given in Table 16.1 and the fact that G° is 25 kJ mol1 (–6 kcal mol1) for the following reaction: Pyruvate + NADH + H+ lactate + NAD+ ; What is the free-energy change (G, not G°) of this reaction when the concentrations of reactants are: glucose, 0.01 M; lactate, 0.000025 M; ATP, 0.002 M; ADP, 0.0002 M; and Pi, 0.001 M? Assume 25 degrees Celcius.

Lactic acid fermentation. (a) Write a balanced equation for the conversion of glucose into lactate. (b) Calculate the standard free-energy change of this reaction by using the data given in Table 16.1 and the fact that G° is 25 kJ mol1 (–6 kcal mol1) for the following reaction: Pyruvate + NADH + H+ lactate + NAD+ ; What is the free-energy change (G, not G°) of this reaction when the concentrations of reactants are: glucose, 0.01 M; lactate, 0.000025 M; ATP, 0.002 M; ADP, 0.0002 M; and Pi, 0.001 M? Assume 25 degrees Celcius.

1 glucose + 2ADP + 2Pi -----> 2lactate + 2ATP; G=-114 kJ/mol 2glucose + 2ADP + 2Pi -----> 2lactate + 2 ATP + 2 AMP; G=10 kJ/mol 1glucose + 1ADP + 1Pi -----> 1lactate + 2ATP; G=-113.4 kJ/mol 1glucose + 2ADP + 2Pi -----> 2lactate + 2ATP; G=-119 kJ/mol 2glucose + 4ADP + 3Pi -----> 1lactate + 2ATP; G=-30.4 kJ/mol

Explanation / Answer

Lactic acid fermentation

(a) equation for glucose to lactate reaction

1glucose + 2ADP + 2Pi ---> 2lactate + 2ATP

Using relation,

dG = dGo + RTlnK

dGo = 25 kJ/mol

Feeding concentration values,

dG = -114 kJ/mol