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Consider the reaction: Glucose + Pi = glucose 6-phosphate + H₂O. What is the equiLiBrium constant, K'eq, for this reaction? (Note: the concentration of water is ignored.) Does the positive DG°' in the above reaction mean that the reaction can never go spontaneously from left to right?

User IFederx
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Final answer:

The equilibrium constant (K'eq) refers to the ratio of product to reactant concentrations at equilibrium. A positive standard Gibbs free energy change (ΔG°') for a reaction indicates that under standard conditions, the equilibrium constant is less than 1, favoring reactants, but the reaction can still proceed spontaneously under different conditions.

Step-by-step explanation:

The question addresses the equilibrium constant (K'eq) for the biochemical reaction where glucose is phosphorylated to glucose 6-phosphate. The mention of ΔG°' refers to the standard Gibbs free energy change for the reaction, and the student is asking if a positive ΔG°' means the reaction cannot proceed spontaneously from glucose to glucose 6-phosphate.

The fundamental relationship in thermodynamics is ΔG° = -RTlnK, which connects the Gibbs free energy change to the equilibrium constant (K). A positive ΔG°' value implies that the equilibrium constant K'eq for this particular reaction is less than 1 under standard conditions, indicating that the reactants are favored over the products. However, this does not necessarily mean that the reaction cannot occur spontaneously under certain conditions because the actual Gibbs free energy change (ΔG) also depends on the concentration of reactants and products (the reaction quotient, Q) and non-standard conditions.

User Saikiran Yerram
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