The sugar (C12H22O11) from sugarcane and grapes in the presence of an enzyme invertase produces
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → glucose and fructose
The sugar \( \ce{C12H22O11} \) is sucrose, a disaccharide made of one glucose unit and one fructose unit. In the manufacture of ethanol by fermentation, sugar from molasses, sugarcane or fruits such as grapes is broken down in two enzyme steps:
Invertase hydrolyses sucrose into glucose and fructose.
Zymase (from yeast) then converts glucose and fructose into ethanol and carbon dioxide.
\( \displaystyle \ce{C12H22O11 + H2O} \xrightarrow{\text{invertase}} \ce{C6H12O6}\text{ (glucose)} + \ce{C6H12O6}\text{ (fructose)} \)
\( \displaystyle \ce{C6H12O6} \xrightarrow{\text{zymase}} \ce{2C2H5OH + 2CO2} \)
So invertase produces glucose and fructose.
Why the other options are incorrect
Option (1) methanol and ethanol — Incorrect. Methanol is not formed in fermentation, and ethanol forms only in the next step, with zymase.
Option (3) ethanol and glucose — Incorrect. Invertase does not produce ethanol; ethanol comes from glucose in the zymase step.
Option (4) sucrose and fructose — Incorrect. Sucrose is the sugar being hydrolysed, not a product.
NCERT (2026-27 edition):
Ethanol
