Which of the following gives the enzyme that catalyses the hydrolysis of maltose and the products of this hydrolysis?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Maltase; two molecules of glucose
Enzymes are biocatalysts that are very specific for a particular reaction and a particular substrate. They are generally named after the compound they work on, with the ending -ase: the enzyme that hydrolyses maltose is maltase.
Maltose is made of two α-D-glucose units, so its hydrolysis gives two molecules of glucose:
\( \displaystyle \ce{C12H22O11 + H2O} \xrightarrow{\text{Maltase}} \ce{2C6H12O6} \)
Maltose → Glucose
Why the other options are incorrect
Option (2) Sucrase; two molecules of glucose — Incorrect. Sucrase acts on sucrose, not on maltose; an enzyme is specific for its substrate.
Option (3) Maltase; one molecule each of glucose and fructose — Incorrect. Glucose and fructose are the products from sucrose: \( \ce{C12H22O11 + H2O -> C6H12O6 + C6H12O6} \) (glucose + fructose). Maltose has no fructose unit.
Option (4) Sucrase; one molecule each of glucose and fructose — Incorrect. This is the enzyme hydrolysis of sucrose, not of maltose.
NCERT (2026-27 edition):
10.3 Enzymes – “…They are generally named after the compound or class of compounds upon which they work. For example, the enzyme that catalyses hydrolysis of maltose into glucose is named as maltase.”
\( \displaystyle \ce{C12H22O11} \xrightarrow{\text{Maltase}} \ce{2C6H12O6} \)
Maltose → Glucose