A food stall owner was preparing dough for making bhaturas He added a pinch of yeast and sugar to th...

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 a few hours, the dough had risen. There was a sour smell too.

(a) Why did the dough rise?

(b) Why did the dough smell sour?

(c) Why was sugar added to the dough?

(d) What would have happened if the dough was kept in the refrigerator, soon after it was prepared?

Accepted Answer

a CO2 produced by yeast during respiration makes the dough rise b During anaerobic respiration yeast produces alcohol This gives sour smell to the dough c Sugar acts as food for yeast d If kept in the refrigerator yeast will not respire and multiply and the dough will not rise and will not produce a sour smell

NCERT Exemplar Solutions Class 7 Science Solutions for Respiration in Organisms - Exercise in Chapter 10 - Respiration in Organisms