Sucrose is converted to glucose and fructose in the presence of an enzyme, invertase or sucrose. Glucose and fructose undergo fermentation in the presence of another enzyme, zymase. Both these enzymes are present in yeast.
`underset("Sucrose")(C_(12)H_(22)O_(11))+H_(2)O overset("Invertase"//"sucrose")rarr underset("Glucose")(C_(6)H_(12)O_(6))+underset("Fructose")(C_(6)H_(12)O_(6))`
`underset("Glucose"//"Fructose")(C_(6)H_(12)O_(6)) overset("Zymase")rarr underset("Ethanol")(2CH_(3)CH_(2)OH)+2CO_(2)`