Question

When one mole of lactose is hydrolysed, the hydrolysate contains ____________.

Options

• 1.0 mol Glucose + 2.0 mole Galactose

• 1.0 mol Galactose + 1.0 mol Glucose

• 2.0 mol Glucose

• 1.0 mol Glucose + 1.0 mol Fructose

Answer 1

When one mole of lactose is hydrolysed, the hydrolysate contains 1.0 mol Galactose + 1.0 mol Glucose.

Explanation:

When lactose is hydrolyzed in the presence of an acid or the enzyme lactase, one molecule of glucose and one molecule of galactose are produced.

\[\ce{\underset{Lactose}{C12H22O11} + H2O ->[H3O^+][or lactase] \underset{D-(+)Glucose}{C6H12O6} + \underset{D-(+)-Galactose}{C6H12O6}}\]