Question

A food stall owner was preparing dough for making bhaturas. He added a pinch of yeast and sugar to the dough and left it in a warm place. After few hours, the dough had risen. There was a sour smell too.

Why did the dough rise?

Answer 1

Yeast undergoes anaerobic respiration (in the absence of oxygen) and produces ethyl alcohol and carbon dioxide. The CO₂ released during respiration by the yeast results in the rise of the dough.