Question

Although the ΔG of an enzyme reaction ultimately determines its fate, the equilibrium constant can provide some insight. The equilibrium constant (K’eq) for the conversion of the disaccharide sucrose to the simple sugars glucose and fructose is 140,000. What can you conclude about the following reaction? sucrose + H2O ↔ glucose + fructose

Answer 1

This is a hydrolysis reaction.

The disaccharide glucose is hydrolyzed to the two monosaccharides glucose and fructose

The balance between the forward and reverse reactions is known as the chemical equilibrium.

For the above reaction

Keq = [Glucose] [fructose]\[sucrose][H20] = 140,000

The above chemical reaction can run in both the forward and reverse directions,

but the products glucose and fructose are at a lower energy level than the reactant sucrose.

This is a spontaneous reaction beginning with sucrose because K_eq > 1.