A study using an O2 electrode to measure the amount of O2 produced or consumed over an amount of time with varying light intensities to determine the effect of light intensity, CO2 and diuron on the rate of photosynthesis of Spinacia oleracea.
Introduction
Photosynthesis is the process in which chloroplasts found in plants, algae and some bacteria are used to convert light energy to chemical food energy. (Reece, et al. 2012, p. 190)(Molecules, Genes & Cells Laboratory Manual 2016) .
Photosynthesis can be broken down into two parts, light dependent reactions and light independent. Light dependent reactions use light energy collected by the thylakoid to convert NADP+ and ADP to NADPH and ATP respectively (Cloot 1994, p. 23). This process is …show more content…
Respiration occurs in all living organisms and is separate from photosynthesis (Molecules, Genes & Cells Laboratory Manual 2016). Oxygen is consumed in this process and carbon dioxide is one of the products (Reece, et al. 2012, p. 169-184).
Diuron is a herbicide that will be used in this experiment. Diuron inhibits photosynthesis as found in a study by Harrington, et al. (2005).
The hypothesis being tested is that as the light intensity is increased the rate of photosynthesis will increase.
Materials and Methods
The procedure as set out in the Molecules, Genes and Cells Laboratory Manual (2016) was followed.
A 50 mM HEPES buffer at pH 7.6 was used. The light intensity was varied from the most intense light to no light, the levels of light used were 1000, 50, 10 and 0 µmol photons m-2 s -1. After the steady rate at 0 µmol photons m-2 s -1 was recorded the light intensity was returned to maximum and Diuron was added. A short time after the amount of O2 the electrode could measure maxed out. To rectify this issue nitrogen gas was bubbled into the chamber to remove some oxygen. The chamber was once again sealed and a steady rate in the presence of Diuron was recorded.
Introduction
Photosynthesis is the process in which chloroplasts found in plants, algae and some bacteria are used to convert light energy to chemical food energy. (Reece, et al. 2012, p. 190)(Molecules, Genes & Cells Laboratory Manual 2016) .
Photosynthesis can be broken down into two parts, light dependent reactions and light independent. Light dependent reactions use light energy collected by the thylakoid to convert NADP+ and ADP to NADPH and ATP respectively (Cloot 1994, p. 23). This process is …show more content…
Respiration occurs in all living organisms and is separate from photosynthesis (Molecules, Genes & Cells Laboratory Manual 2016). Oxygen is consumed in this process and carbon dioxide is one of the products (Reece, et al. 2012, p. 169-184).
Diuron is a herbicide that will be used in this experiment. Diuron inhibits photosynthesis as found in a study by Harrington, et al. (2005).
The hypothesis being tested is that as the light intensity is increased the rate of photosynthesis will increase.
Materials and Methods
The procedure as set out in the Molecules, Genes and Cells Laboratory Manual (2016) was followed.
A 50 mM HEPES buffer at pH 7.6 was used. The light intensity was varied from the most intense light to no light, the levels of light used were 1000, 50, 10 and 0 µmol photons m-2 s -1. After the steady rate at 0 µmol photons m-2 s -1 was recorded the light intensity was returned to maximum and Diuron was added. A short time after the amount of O2 the electrode could measure maxed out. To rectify this issue nitrogen gas was bubbled into the chamber to remove some oxygen. The chamber was once again sealed and a steady rate in the presence of Diuron was recorded.