Photosynthesis is a very complex process which is divided into two phases. The first phase is called the light-dependent reaction, this is when chlorophyll absorbs light energy. The products of the light-dependent reaction are ATP and NADPH which will be used in the second phase. The second phase is called carbon fixation and does not require any light. In this light independent reaction ATP NADPH and CO2 are used to make the carbohydrate glucose, which is a six carbon monosaccharide (Dickey, Jean 2003). Photosynthesis takes place in the chloroplasts of plants. Chloroplasts contain all of the materials needed to make this process happen such as the chlorophyll and the enzymes as well as other molecules. .
As stated the first phase of photosynthesis is the light-dependent reaction. In this reaction the light energy is used to split water molecules and O2 is released as a by product. We used this aspect of the process to conduct an experiment and also create our own experiment. Leaf tissue is filled with gas in the intercellular spaces, because it is filled with gas a leaf will always float. A way to get rid of this gas is by putting it in a solution where we can then make a vacuum. When the leaf is placed in the solution it is obvious it will float but if a vacuum is made the gas is replaced with the solution and the leaf will sink. We can use the fact that O2 is produced in the light reaction of photosynthesis, this reaction will make the solution be replaced with gas and make the leaf float. This technique was used for our experiment, to measure the rate of photosynthesis. Our hypothesis was that a color pigment in a leaf, rather than green, will make the rate of photosynthesis much slower. .
