Photosynthesis And Cellular Respiration Lab Report

1180 Words 5 Pages
Determining The Process of Photosynthesis And Cellular Respiration Using Elodea and Yeast

Photosynthesis is an essential process to life on earth, in which plants and other organisms use sunlight to create food from oxygen, and carbon dioxide. Cellular respiration is when energy in food is released and converted to ATP, which is then used as chemical energy to complete tasks within a cell. This process usually requires oxygen and releases carbon dioxide. Photosynthesis and cellular respiration are similar in some areas and different in others. The purpose of both of the process is to produce energy, but they have different ways of achieving this goal. Photosynthesis uses two electron transport chains, energy is by photons, also
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The initial color was recorded.
The “dark” set of tubes was covered with aluminum foil and set in darkness, and the “light” tubes set in a brightly lit area, each for 30-40 minutes.
The observations were recorded at the end.

Part B
Two test tubes were labeled, one with “yeast” and the other with “water”.
1 ml of yeast suspension and 4 ml of distilled water was added to the “yeast’ labeled tube.
5 ml of distilled water was added to the “water” tube.
5 ml of sucrose solution was added to each test tube and stirred.
5 drops of bromothymol blue indicator was added to each tube.
Drops of sodium hydroxide solution was added dropwise to both test tubes and gently mixed until the solutions turned blue. The observations were recorded.
The tubes were set to incubate at room temperature for 20 minutes and checked at 5 minute intervals to record the observations.
The yeast cultures were disposed.

In the light reaction Elodea stayed the same color when it was not exposed to light and turned color in the dark. This is because of photosynthesis and cellular respiration making oxygen and carbon dioxide. When the tubes were in the dark they turned yellow because of cellular respiration and carbon
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Two contained Elodea and two did not, two were placed in the light and two were not. What was the purpose of using all four tubes? To test different variables.
Bromothymol blue is a substance from a family of chemicals known as indicators. Research this chemical and state why you believe it was added to the tubes in both of these experiments. I believe it was added because it is an indicator that can change color in the presence of carbon dioxide and acts as an indicator of photosynthesis.
Examine the three graphs below. Which do you think most accurately represents the results you would see if you were to increase light when performing Part A of the experiment? Why? B, because there is less reaction in the presence of light.
In the second experiment, do you believe the yeast was undergoing aerobic or anaerobic respiration? Why? Anaerobic because there reaction did not require energy and it was undergoing photosynthesis .
What do you believe would happen if you sealed the ends of your tubes before making observations in the second experiment? It would become an aerobic

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