Friday, December 16, 2011

Photosynthesis “Dry Lab”

Materials:
  •        5 test tubes
  •        Bromothymol Blue (BTB)
  •        Water
  •        Pippet
  •        An aquarium fish
  •        Elodea
  •        Timer



Procedure:
1.    Label each test tube Bromothymol Blue +Water, Water + Bromothymol Blue + Aquarium Fish,  Water + Bromothymol Blue + Elodea, and Water + Bromothymol Blue + Aquarium Fish + Elodea
2.    In one test tube put in pond water and bromothymol
3.    Write down observations
a.    Solution should stay blue-green
4.    In the second test tube put in pond  water and Bromothymol this time add the aquarium fish in the solution
5.    Write observation
a.    Should turn solution yellow
6.    In the third and fourth test tube put pond water and bromothymol this time instead of the aquarium fish you add elodea .
7.    Put one test tube in light for three hours and one in the dark for three hours
8.    Write observations after three hours are up
a.    The one in the light should turn blue-green
b.    The one in the dark should turn yellow
9.    For your final experiment you will need two test tube
10.                  You than to put pond water and Bromothymol Blue plus both the aquarium fish and elodea in each tube
11.                  Place one tube in a lighted area and place the other in a dark area
12.                  Leave for three hours each
13.                  After three hour take out each tube and write down your observations
a.    The one that was in the light for three hours should bea pale blue-green color
b.    The one in the dark should be a yellow color


       Conclusion


      After performing several different experiemnts the data we collected observed serval reactions. For the first experiment we put in pond water and bromothymol in a test tube. We found that there was no reaction because the pond water and bromothymol are a neutral pH. With the second experiment we added the pond water and Bromothymol but also an aquarium fish. This time we got a reaction, it turned the color yellow. This happened because of the acid from the animal respiring. This time we took two test tubes in both we put in the pond water and bromothymol and added elodea. We tan put one in light for three hours and one in the dark for three hours. The reaction from the one in the light was that it was a blue-green color this is because carbon dioxide + water yeilds sugar and oxygen when chlorophyll and sunlight is present. In the second test tube the one in the dark it reacted by turning yellow.This happened because sunlight wasn’t present so photosythesis could not happen.Finally we took a two test tubes and combined pond wate + bromothymol + an aquarium fish + elodea.  Like the previous experiment one was put under light and one in the dark both for three hours.The one in the light turned a pale gblue-green color. While the one in the dark turned yellow.I believe that these reacted the same as the previous experiments for the same reason, sunlight was present in the first one and in the second photosynthesis didn’t occur. Though the first might be a plae blue-green because of the aquarium fish.

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