Hill Reaction Lab Introduction

In this experiment the goal was to see the effect of certain factors, in this case acids and bases, of the light absorbance of spinach chloroplasts. Chloroplasts are essential to life for both plants and animals alike, they are crucial in the photosynthetic reaction that produces oxygen and glucose from carbon dioxide, light and water. In the spinach chloroplasts there are two separate photosystems that convert light energy and water to oxygen and glucose. In this experiment the chloroplasts were extracted from approximately six spinach leaves and suspended in grinding buffer. 50 microliters of the chloroplast were then placed into four differently treated test tubes (dark, light, light and vinegar and light with bleach), leaving one test tube without chloroplast as the control group. The light absorbance of each test tube was tested every 10 minutes for 30 minutes. If bleach and vinegar are added to the chloroplast then we can expect the function of chloroplasts to be hindered because the acid and base produce an environment that is outside the optimal ph for functioning chloroplasts. More specifically we can expect the bleach to completely neutralize the chloroplast and for the vinegar to almost completely neutralize the chloroplast, but we can expect limited function. For these predictions to supported we should expect to see the tube with bleach to have 0 light absorbance and for the vinegar treated tube to have a very low light absorbance.