Photosynthesis Lab Report

Photosynthesis and the Amount of Light

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I. Introduction

Photosynthesis the process where plants use sunlight (energy) to synthesize foods forming the products carbohydrates and water (H20 + CO2 + Light CH2O + O2). For photosynthesis to take place they need water, carbon dioxide and light and chloroplasts. Light is absorbed inside he thylakoid membrane of the chloroplasts, and the carbohydrate reaction or synthesis takes place in the stroma. In plants there are five kinds of chlorophylls with the same basic structure, chlorophylls occur as greenish pigments and capture light
We labeled the test tubes with numbers one through five. The first test tube was our calibration tube, here we added one milliliter (mL) of buffer, four mL of distilled water and three drops of chloroplasts using pipets. After, we created the solution for the second, third, fourth and fifth test tubes by adding one mL of buffer, three mL of distilled water one mL of DPIP an 3 drops of chloroplasts. However, we decided that test tube number two was going to be the test tube that was kept completely out of the light (as our control) and therefore we covered the tube with foil (Figure1). The control group was used to measure any transmittance that was happening without light, so that we could compare the other tubes that all had a fixed amount of light to it.. We set up the different amounts of light using stations that would correspond to specific test tubes. The first station contained no extra lights being added, the second station contained one light (1 bulb), the third station contained two lights (2 light bulbs) and the fourth contained three lights (3 bulbs). There was no fifth station because our test tube number two was kept in the dark. We then measured the transmittance in four runs, using the spectrometer and recorded our results (Figure
We placed each test tube (one at a time) into the spectrometer and recorded their values of transmittance for run one, making sure to wipe the test tubes from fingerprints using Kimwipes. Then, we placed each of the test tubes under the specific station they corresponded to and let them sit for five minutes. The test tube labeled one was the calibration tube, and because no extra light was being added to it we placed it into the test tube holder (under no light) at station one. The second test tube did not have a particular station because it was kept in aluminum foil so one of our group members held it. The third test tube was placed at the station where there was one extra light (1 light bulb), the fourth test tube was placed at the station containing two extra lights (2 light bulbs) and the fifth test tube was placed at the fourth station that contained three extra lights (3 light bulbs). After five minuets elapsed, we then placed each test tube (one at a time) into the spectrometer and recorded their values of transmittance for run two, making sure to wipe the test tubes from fingerprints using Kimwipes. Then, we placed each test tube back under their same specific station that they corresponded to and let them sit for another five minutes (again, one group member held test tube two). When the five minuets was over we placed each test tube (one at a time) into the spectrometer, making