Photosynthesis Lab

In this lab, we didn't actually perform the lab ourselves, our class only observed. We learned about BTB. BTB is a solution that is blue green in light alone, however, when carbon dioxide is present it turns a yellow color. BTB will also turn also yellow if it is left in the dark for 3 hours. Water mixed with BTB keeps it at a neutral PH which means the color of the BTB will stay at blue green. We took fish respire and added sugar with O2 and CO2 and H2O and this turned into CO2 in H2O which is an acid and this made the BTB turn a yellow color because of the presence of the carbon dioxide. We discover that the fish respire gives off sugar and oxygen, carbon dioxide and water. Elodea is a plant that is pale blue green in the light and yellow when it is left in the dark for 3 hours. This is a plant that is constantly is desperation and it gives off carbon dioxide and BTB which makes it yellow and blue green. This plant picks up carbon dioxide and stays blue green instead of turning yellow.

Above is a photograph of Elodea. As you can see, this Elodea plant is a yellowish green. This plant has most likely been in the dark for awhile, as the blue color is not present.