Spinacia Oleracea Lab Report
MGC 2018 Practical write up
Name: Madison Bielby
Student number: a1740189
Word Count:
TITLE
A study using an oxygen electrode to determine the effects of varying light intensity on the rate of photosynthesis of spinach, Spinacia oleracea.
INTRODUCTION
Photosynthesis is a two-stage process, each with multiple reactions, which must work concurrently with each other in order for plant survival. The first stage of photosynthesis is the light dependent reactions which occur in the thylakoids followed by the second stage called the Calvin cycle which occurs in the stroma. The light dependent reactions do not involve carbon dioxide, only water. However, the Calvin cycle does require carbon dioxide.
The light dependent reactions involve two photosystems and an electron transport chain. A photon from light strikes a pigment molecule in photosystem two, which excites one of its electrons to a higher energy state. This excited electron is then transferred to the primary electron acceptor. In order to replace the electron, enzymes catalyse the splitting of water, producing two electrons, two hydrogen ions and an oxygen atom. The electrons from …show more content…
The initially increase, between 0 and 150 μmol photons m-2 s-1 was linear when the light intensity was low or restrictive. As the light intensity increased, from 150 to 800 μmol photons m-2 s-1 the rate of respiration began to plateau. To calculate the true rate of photosynthesis a control trial which had a light intensity of zero was conducted which gave the rate of respiration as 0.8028 μg O2L-1s-1. This result was added to the measured rate of oxygen production to determine the true rate of photosynthesis. The first measurement of photosynthesis, which had a light intensity of 800 μmoles photons.m-2s-1 and no additionally NaHCO3 was not included in the figure. The light compensation point was 125 μmol photons m-2
Name: Madison Bielby
Student number: a1740189
Word Count:
TITLE
A study using an oxygen electrode to determine the effects of varying light intensity on the rate of photosynthesis of spinach, Spinacia oleracea.
INTRODUCTION
Photosynthesis is a two-stage process, each with multiple reactions, which must work concurrently with each other in order for plant survival. The first stage of photosynthesis is the light dependent reactions which occur in the thylakoids followed by the second stage called the Calvin cycle which occurs in the stroma. The light dependent reactions do not involve carbon dioxide, only water. However, the Calvin cycle does require carbon dioxide.
The light dependent reactions involve two photosystems and an electron transport chain. A photon from light strikes a pigment molecule in photosystem two, which excites one of its electrons to a higher energy state. This excited electron is then transferred to the primary electron acceptor. In order to replace the electron, enzymes catalyse the splitting of water, producing two electrons, two hydrogen ions and an oxygen atom. The electrons from …show more content…
The initially increase, between 0 and 150 μmol photons m-2 s-1 was linear when the light intensity was low or restrictive. As the light intensity increased, from 150 to 800 μmol photons m-2 s-1 the rate of respiration began to plateau. To calculate the true rate of photosynthesis a control trial which had a light intensity of zero was conducted which gave the rate of respiration as 0.8028 μg O2L-1s-1. This result was added to the measured rate of oxygen production to determine the true rate of photosynthesis. The first measurement of photosynthesis, which had a light intensity of 800 μmoles photons.m-2s-1 and no additionally NaHCO3 was not included in the figure. The light compensation point was 125 μmol photons m-2