4. Complete Activity 2.4 (Page 20). Take a 500 mL beaker filled upto ¾ with water. Dissolve 2-3 teaspoons of sugar in it. Add half a spoon of yeast powder to the sugar solution. Keep it covered in a warm place for 4-5 hours. Now smell the solution. Can you get a smell?
Answer: The above activity can be carried out as follows:
Aim: To smell the solution after two hours and make the necessary conclusions.
Materials Required: 500 mL beaker, water, 2-3 teaspoons of sugar, yeast powder.
Procedure:
(i) Fill the 500 mL beaker upto ¾ with water.
(ii) Dissolve 2-3 teaspoons of sugar in it and add half a spoon of yeast powder to the sugar solution.
(iii) Keep it covered in a warm place for 4-5 hours and smell the solution.
Observations:
After 4-5 hours you will get a pungent smell from the solution.
Conclusions:
We conclude that yeast converted sugar into alcohol (ethanol) by the process of fermentation and this gave us the pungent smell.
“Take a 500 mL beaker filled upto ¾ with water. Dissolve 2-3 teaspoons of sugar in it. Add half a spoon of yeast powder to the sugar solution. Keep it covered in a warm place for 4-5 hours. Now smell the solution. Can you get a smell?” – Solved.
Related Links:
Solution to Extended Learning Problem 1
Solution to Extended Learning Problem 2
Solution to Extended Learning Problem 3
Solution to Extended Learning Problem 4
Solution to Activity 2.1
Solution to Activity 2.2
Solution to Activity 2.3
Solution to Activity 2.5
Solutions to Chapter 2 Microorganisms: Friend and Foe
