2. Green plants use sunlight to make glucose in a process called
Photosynthesis
6CO H2O  C6H12O O2
Green plants use sunlight to make glucose in a process called
Cellular Respiration
C6H O2  6CO H2O
Fungi and other heterotrophic organisms use sugar to make ATP – the energy molecule necessary to sustain life. 2

3. 6CO2 + 6H2O  C6H12O6 + 6O2 6CO2 + 6H2O  C6H12O6 + 6O2
carbon dioxide water  glucose oxygen
How is the glucose made by plants used by plants and animals as a source of energy?
6CO2
carbon dioxide
+ 6H2O
water 
C6H12O6
glucose
+ 6O2
oxygen
To release the energy contained in the bonds of glucose, the glucose must be converted to ATP. The process by which ATP is made from glucose is called cellular respiration. 3

4. Sunlight is to a plant like gasoline is to a car.
Can photosynthesis occur without sunlight?
Explain the following statement:
Sunlight is to a plant like gasoline is to a car.
What happens when the sun goes down?
Can cellular respiration occur in yeast without the presence of sugar? 4

5. Photosynthesis
In water, carbon dioxide dissolves to form a weak acid. As a result, an acid-base indicator such as bromothymol blue can be used to indicate the presence of carbon dioxide.
In this laboratory investigation, you will use bromthymol blue to observe the effects of photosynthesis.
Using the straw GENTLY blow one lung full of air into the test tube containing bromthymol blue.
Put approximately 3cm sprig of elodea into the test tube.
Place the test tube in the test tube rack under the light.
Turn the light on. If necessary, adjust the lamp so that it is shining directly on the test tube. 5

6. Cellular Respiration
Dried yeast requires heat and water to become “activated”. Yeast is a fungus that processes sugar through cellular respiration. In this laboratory experiment you will use warmed sugar water and a balloon to capture the gasses released by the yeast through cellular respiration.
Mix 4 table spoons sugar with 300mls of water.
Place 20mls warmed sugar water into a test tube.
Add ¼ teaspoon dried yeast.
Gently shake test tube to mix.
Cover with a balloon and wait. 6

7. Photosynthesis 6 H2O + 6CO2  C6H1206 + O2 C6H1206 + O2  6CO2 + 6 H2O
What will happen to the level of CO2 in the water containing the elodea?
Cellular Respiration
C6H O2  6CO2 + 6 H2O
What will happen to the balloon covering the top of the tube filled with sugar, H2O, & yeast? 7

8. In your BIN:
Below your hypothesis write background information (learned in this class discussion) that explains photosynthesis & cellular respiration.
Next, examine the test tubes.
Write down your observations. Has there been in change? Be descriptive.
Finally, write a conclusion which briefly explains what was done in this experiment, what the results are and why these results occurred. Finish your conclusion with what you might expect to happen in your test tube if it were left in the dark over night. Explain your prediction. 8