Photosynthesis and Cellular Respiration Stations
Station #1 Photosynthesis: measure the distance from the top of the
test tube to the light bulb. Add a pinch of baking soda and record data.
Distance
Number of
Number of
Number of
(inches)
bubbles (1 min)
bubbles (2 min)
bubbles (3 min)
9 1/2
2
0 (dark)
1. From what part of the elodea are the bubbles emerging?
2. How does the intensity of light (distance from the plant) affect the rate of photosynthesis?
3. Why do we use the baking soda?
Station #2 Fill in the blank for the following reading exert
1.
6.
2.
3.
4.
5.
7.
8.
9.
10.
Station #3 Investigating how Yeast go through cellular respiration: Did you ever wonder how bread gets its
"spongy" structure? If you've ever baked homemade bread yourself, you know that you need yeast to make the
bread dough rise. Yeasts are single-celled fungi. Like the cells in your body, they can derive energy from sugar
molecules. They can also break down larger carbohydrate molecules (like starches present in flour) into simple
sugar molecules, which are then processed further; this is called cellular respiration.
Yeast can extract more energy from sugar when oxygen is present in their environment. In the absence of oxygen,
yeast switch to a process called fermentation. With fermentation, yeast can still get energy from sugar, but less
energy is derived from each sugar molecule. When oxygen is present, the sugar molecules are broken down into
carbon dioxide and water (plus energy that the yeast uses to grow and reproduce). In the absence of oxygen, the
sugar molecules are not broken down completely. The end products are alcohol (with two carbon atoms) carbon
dioxide (one carbon atom), and water. Less energy is extracted from each sugar molecule: the energy that could be
extracted from the alcohol molecule if oxygen were present. As you know, carbon dioxide is a gas. In bread dough,
carbon dioxide produced by yeast forms bubbles that make the dough rise, and give bread its spongy texture.
1. Measure the circumference of the balloon with string and ruler and fill in data table:
Circumference of balloon (cm)
sugar
Fruit juice
No sugar
2. Using the information above, what physical evidence proves that yeast carry on cellular respiration?
Photosynthesis and Cellular Respiration Stations
3. The yeast began its respiration aerobically (with oxygen), but then after time completed it anaerobically
(without oxygen). How does fermentation and cellular respiration differ in the products made? List two ways in
which these processes are similar?
Station #4: Use the pictures and chalk to practice writing both of the equations out and adding the pictures where
they go.
Station #5 Microviewer: You will observe the chloroplast and mitochondria under the microviewer, illustrate the
pictures, label them, and answer the questions below.
1. Where does Cellular Respiration occur?
2. What is needed in order to break down glucose in the mitochondria, unless you are going through
fermentation?
3. Where does photosynthesis occur?
4. What is the pigment that makes it possible for plant cells to trap the energy from sunlight?
Station #6 Stomata
Information: Guard cells are responsible for opening and closing the stoma. When water concentration is high, the
guard cells will bulge, and cause the stoma to open. When the water concentration is low, the stoma will close.
Stoma are generally open when plants are photosynthesizing.
Question: Will plants have more stoma open during the day than during the night?
2. You have two prepared slides one from a "Dark Plant" and one from a "Light Plant" You will compare the two
slides. Count the stomata from each and enter it in the data table:
Plant
Number of Stomata
Light
Dark
3. Explain your reasoning to the question by using the data you collected.
Illustrate one of the pictures
of stomata