Introduction: Question: What is the biggest contribution to life on this earth? The answer to that is photosynthesis. What exactly is photosynthesis and why is it so important? Te easiest way to define photosynthesis is the process by which plants use carbon dioxide (CO2) and water and turn it into oxygen. Everything living organism is dependable on photosynthesis. The reason that photosynthesis is the most contributive to life on this earth is because every organism needs food, water and oxygen to survive. Living organisms can live without food and water longer then they can without oxygen. In this lab, three demonstrations were set p to show three effects related to photosynthesis. The first demonstration reveals the effects of photosynthesis on leaf buoyancy. To do this, leaves were put in a syringe along with phosphate buffer (to help photosynthesis to occur) and all the oxygen was taken out. This made the leaves sink to the bottom of the syringe. The syringe was then placed in a light. With the light, the leaves were able to photosynthesize and produce oxygen, making them float back to the top. In the second demonstration was electron transfer by chloroplasts. This was performed by testing the clarity of water in a spectrophometer. Three test tubes were created and had water, a chloroplast solution, phosphate buffer and one of the tubes had DCPIP. DCPIP is a dye that when oxidized is blue and when electrons are added, turns clear. The first test tube was used to set up the spectrophometer and the second and third for the actual testing. The third test tube had just water, the phosphate buffer, and chloroplast solution. The second tube had all of the above materials along with the DCPIP solution. The two test tubes were placed under a light for thirty second increments for a total of three minutes. After every thirty seconds, clarity was measured in the spectrophometer and data was recorded.