Photosynthesis

Purpose

This photosynthetic experiment required us to create different mixtures involving phosphate buffer, distilled H2O, DPIP, and then adding either boiled or unboiled chloroplasts. With DPIP and the varying forms of chloroplasts we tested how fast or if photosynthesis was able to occur, and if photosynthesis was able to occur it simply reduced DPIP into the mixture. By doing this we could also track the percentage of transmitance and absorption with the help of a Colorimeter. 

Introduction

DPIP is used in place of NADP in photosynthesis so if photosynthesis does occur, meaning light does enter the chloroplast and excites the electrons to the electron acceptor, DPIP will reduce from it's blue state to a colorless state. This means photosynthesis did occur allowing the spinach cells to create energy. However, if the mixture remained blue after being exposed to light it means that the chloroplasts were damaged and unable to execute light absorption and thus DPIP remained unaltered. 

Method

We created various mixtures pertaining phosphate buffer, distilled H2O, DPIP and then either no chloroplasts for the control group or the tests which included boiled or unboiled chloroplasts. We added the chloroplasts only  after we poured the solutions into cuvettes which were immediately placed into front of a light source dispersed by a flask of water. We then took measures of light transmitance and absorption of the cuvettes using the Vernier colorimeter. 

Picture /\: Colorimeter

Graphs and Charts

Conclusion: in this pigments and photosynthesis lab we butchered the results. We made the mistake of not placing the unboiled chloroplast until after setting up the test tubes. Which caused us to remake the test tubes. Also we messed up by not placing each of the cuvettes in front of the light at the same time. The cuvettes had been in the light for different amount of times. We had to redo that part to get correct results. We placed each one with same time. The final results were correct and completed this lab making it a success. 

Reference: 

AP Bio Lab 4 - Plant Pigments & Photosynthesis." Bozemanscience. N.p., n.d. Web. 08 Dec. 2014

College Board." AP Central. N.p., n.d. Web. 08 Dec. 2014

LabBench." LabBench. N.p., n.d. Web. 08 Dec. 2014

Photosynthesis." - Wikipedia, the Free Encyclopedia. N.p., n.d. Web. 08 Dec. 2014