Experimental Design: Chlorophyll


Introduction
Chlorophyll plays a very important role in the light reactions of photosynthesis. The light reactions of photosynthesis occur in the granum. Light strikes the chlorophyll in photosystem II, which is located on the membrane surrounding the lumen. The electrons in photosystem II are excited and go into an electron transport chain, those electrons are replaced by the electrons from the splitting of water. Next, light strikes photosystem I and the electrons are exited and move into an electron transport chain. The electrons lost from photosystem I are then replaced by the electrons from the electron transport chain. Next, the electron transport chain moves to enzyme reductase, which is where the electrons from the electron transport chain are added to NADP+. By adding electrons to NADP+, NADPH is created. Without chlorophyll the production of NADPH would be stopped and glucose would not be able to be produced.  

Hypothesis
A high amount of chlorophyll in the leaf will cause a high rate of photosynthesis. A high amount of chlorophyll will be found in dark green leaves, while low amounts of chlorophyll will be found in yellow leaves. 

Methods
We will have five different species of leaves, each with a different color. Before the experiment we will calculate the surface area of each leaf. Next, we will find the rate of photosynthesis for each species of leaves by finding the rate of photosynthesis and respiration together, and respiration alone. This can be done by putting the leaves in light for ten minutes and using a CO2 probe to measure the rate of photosynthesis and respiration. The rate of respiration will be found by wrapping the test tube in aluminum. The rate of photosynthesis and respiration will be subtracted from the rate of respiration, this will give us the rate of photosynthesis. Also, we will divide the rate of photosynthesis by the surface area. After the experiment, we will use spectrophotometry to find out the amount of chlorophyll in each species of leaves.

Predictive Results
The graph below shows how the amount of chlorophyll affects the rate of photosynthesis. As the amount of chlorophyll increases, the rate of photosynthesis increases also.
https://sites.google.com/a/gpschools.com/quarter-4/experimental-design/image%20(1).png

The following graph shows how the leaf color affects the amount of chlorophyll in the plant. As the leaf color is more green, the amount of chlorophyll increases. However, yellow and red leaves have lower chlorophyll concentrations than green leaves.
https://sites.google.com/a/gpschools.com/quarter-4/experimental-design/image.png

Predictive Conclusions
As seen from the graph, as the amount of chlorophyll in the leaves increases, then the rate of photosynthesis will increase. This shows the plants rely on a high amount of chlorophyll to do photosynthesis. In addition, the green leaves had a high amount of chlorophyll, which means they would have a high rate of photosynthesis. Yellow and red leaves, however, have a lower amount of chlorophyll in their leaves, so they have lower rates of photosynthesis. 



https://sites.google.com/a/gpschools.com/quarter-4/experimental-design/biobook_photosyn_2.png