Question

Name the organism and enzyme which brings about the alcoholic fermentation of sucrose.

Answer 1

Saccharomyces cerevisiae is the yeast species which produces the enzyme invertase and zymase responsible for the alcoholic fermentation of sucrose. The sugarcane molasses containing sucrose is generally used as the fermentation medium. The yeast cells are grown in this medium to perform anaerobic respiration which produces ethanol and carbon dioxide. 

\[\ce{\underset{Sucrose}{C12H22O11} + H2O ->[Invertase]\underset{Glucose}{C6H12O6} + \underset{fructose}{C6H12O6}}\] 

This mixture is converted to ethanol by the enzyme zymase.

\[\ce{\underset{Glucose or fructose}{C6H12O6}->[Zymase]\underset{ethanol}{2C2H5OH} + 2CO2}\]