Effects of Wavelength and Light Intensity on Photosynthetic Activity Essay Example
Effects of Wavelength and Light Intensity on Photosynthetic Activity
ABSTRACT
The photosynthetic process of eukaryotes revolves around chlorophyll, the substance that give plants their green color. Plants convert light energy into chemical energy by means of photosynthesis. This experiment tests the reaction rates of a chloroplast suspension against variables of wavelengths and light intensity. Both a control and an experimental cuvette were exposed to a range of 450 to 750nm of light and varying intensities to test for reaction rates. These effects on rate were obtained by measuring the absorbance of DCPIP on a spectrophotometer after 16 minutes.
We hypothesize that the least effective wavelength will be that which is reflected back at us in broad day light, this being green light of about 545 nm in wavelength. In regards to intensity, we hypothesize that the most intense source of light will result in the greatest photosynthetic activity based on the resource availability principle. The results clearly demonstrate the ideal conditions in each set of given variables for an optimum reaction rate and also reflect upon the chemical structure of chlorophyll itself.
INTRODUCTION
The goal of this experiment is to test the effects of wavelength and intensity on a solution of photosynthetic chloroplasts.
We tested photosynthetic activity through the absorption of light on 2,6-dichlorophenolindophenol (DCPIP). DCPIP is an artificial electron acceptor; DCPIP serves as the electron acceptor to the light reactions of photosynthesis and will substitute for NADP+. Absorbance can be measured using a spectrophotometer because prior to being reduced by the electrons from the light reactions, DCPIP is blue in color, and as it accepts electrons it becomes colorless. (Vliet, 2006)
The complex photosynthetic process utilized by eukaryotes is one that converts gaseous CO2 into glucose through the use of light energy, water, and adenosine triphosphate (ATP). Photosynthesis
ABSTRACT
The photosynthetic process of eukaryotes revolves around chlorophyll, the substance that give plants their green color. Plants convert light energy into chemical energy by means of photosynthesis. This experiment tests the reaction rates of a chloroplast suspension against variables of wavelengths and light intensity. Both a control and an experimental cuvette were exposed to a range of 450 to 750nm of light and varying intensities to test for reaction rates. These effects on rate were obtained by measuring the absorbance of DCPIP on a spectrophotometer after 16 minutes.
We hypothesize that the least effective wavelength will be that which is reflected back at us in broad day light, this being green light of about 545 nm in wavelength. In regards to intensity, we hypothesize that the most intense source of light will result in the greatest photosynthetic activity based on the resource availability principle. The results clearly demonstrate the ideal conditions in each set of given variables for an optimum reaction rate and also reflect upon the chemical structure of chlorophyll itself.
INTRODUCTION
The goal of this experiment is to test the effects of wavelength and intensity on a solution of photosynthetic chloroplasts.
We tested photosynthetic activity through the absorption of light on 2,6-dichlorophenolindophenol (DCPIP). DCPIP is an artificial electron acceptor; DCPIP serves as the electron acceptor to the light reactions of photosynthesis and will substitute for NADP+. Absorbance can be measured using a spectrophotometer because prior to being reduced by the electrons from the light reactions, DCPIP is blue in color, and as it accepts electrons it becomes colorless. (Vliet, 2006)
The complex photosynthetic process utilized by eukaryotes is one that converts gaseous CO2 into glucose through the use of light energy, water, and adenosine triphosphate (ATP). Photosynthesis