The document describes an experiment on the effect of temperature on yeast respiration. Yeast, sugar water, and markers are added to glasses with different water temperatures. The yeast growth is measured over time and recorded in graphs. The experiment shows yeast grows fastest in body temperature water and slowest in cold water. It also discusses how yeast undergoes aerobic and anaerobic respiration and is used to produce bread, beer, and wine through fermentation.

5. MATERIAL NEEDED
 Four sachets of baker’s yeast
 Four glasses
 Sugar
 Water
 A kettle
 A marker pen
 Cling film
 Ruler
 Activity paper

6. sugar
•Cold water
•Body temperature
water
•Hot water
4 sachets
of baker’s
yeast

7. A kettle
A marker pen
Ruler

8. Experiment Execution
HOT
WATER
COLD
WATER
BODY
TEMPERATURE
WATER
BODY
TEMPERATURE
WATER

9. Add the same amount
of water (100ml) and
sugar in the glasses
and stir

10. Add the yeast in the
glasses and stir

11. Cover one of the glasses at
body temperature with cling
film
Check every 5 minutes

12. 0 5 10 15 20 25 30 35
DRAWING A GRAPH
HOT WATER
Time cm
5 0
10 0
15 0
20 0
25 0
30 0

13. 0 5 10 15 20 25 30 35
DRAWING A GRAPH
Time cm
5 0
10 0
15 0
20 0.50
25 0.80
30 1.50
COLD WATER

14. 0 5 10 15 20 25 30 35
DRAWING A GRAPH
Time cm
5 2.50
10 6.50
15 9.50
20 12
25 more
30 more
BODY TEMPERATURE WATER

15. Time cm
5 3
10 7
15 8
20 9
25 9
30 8
BODY TEMPERATURE WATER

18. ALTERING VARIABLES
TEMPERATURE
OXYGEN

19. AEROBIC RESPIRATION
Yeast + Sugar solution + Oxygen
Energy released + Carbon dioxide

20. Yeast + Sugar solution
ANAEROBIC RESPIRATION
Carbon dioxide+Energy released+
Ethanol

21. OTHER USES
BREAD
BEER
WINE

22. FINAL TEST
1) In anaerobic respiration, yeast consumes sugars and leaves behind
what?
A. Alcohol and carbon dioxide
B. Carbon dioxide and oxygen
C. Alcohol and oxygen
D. Carbon dioxide
2) If beer is produced by the fermentation of grains, what fermented
product is wine production the result of?
A. Fruit
B. Milk
C. Rice

23. 3) A baker forgets to put yeast in his bread dough. Which of the
following do you expect to happen to the bread as a result?
A. The bread will take longer to cook.
B. The bread will have a sour taste.
C. The bread will not rise.
D. Bacterial contaminants will now be able to grow in the bread.
4) What does yeast consume in aerobic respiration?
A. Carbon dioxide and ethanol.
B. Sugar solution and oxygen.
C. Sugar solution and carbon dioxide.
D. Oxygen and ethanol.

24. 5) Yeast can digest which of the following sugars?
A. Glucose
B. Sucrose
C. Maltose
D. All of the above
6) What are the altering variables?
A. Carbon dioxide and oxygen
B. Oxygen and temperature
C. Carbon dioxide and temperature
D. Oxygen and nitrogen

25. 7) Which is the respiration occurring in the production of beer and
wine?
A. Areobic.
B. Anaerobic.
8) What kind of living organism is yeast?
A. A virus.
B. A multicellular fungus.
C. A bacterium.
D. A single celled fungus.