Determining Rates of Photosynthesis Through Chloroplasts
Introduction:
1)Background=
2) Purpose= measure the rate of photosynthesis in chloroplasts.
3) The chloroplast will be subjected to two experimental conditions- light, and the absence of light, using a spectrophotometer to determine the amount of DPIP reduced at specific time intervals under each condition.
4) I predict the amount of DPIP reduced will vary for each condition and increase over the time intervals. I hypothesize under the light condition the amount of DPIP will drastically be reduced within each five minute time interval. However, under the dark condition the DPIP will not be reduced due to the fact that light is required for photosynthesis.
5) The rates of photosynthesis in each of these reactions will be measured by the amount of light reaching the photocell in the spectrophotometer. This data will be a percentage that represents the amount of DPIP reduced.
Methods
DPIP will be used to determine the rate at which the cholorplasts are being reduced. The spectrophotometer will establish the wavelength of light that penitrats the chloroplast solution in turn determining the amount of electrons reduced. In the dark reactions, the spectrophotometer will measure the amount of light passing through a darker solution of DPIP and chloroplasts. In the light reactions, the lighter solution, caused by reduction of the chloroplasts, will allow a larger amount of light to pass through to the photocell of the spectrophotometer. Thus, the spectrophotometer will prove wheter the light or dark reactions affect the rate of photosynthesis in chloroplasts. We will also be using a reference solution made of water, phosphate buffer, and active chloroplasts. The purpose of this solution will be used to set the transmittance level for the experiment. The control solution, which is different than the reference solution, is comprised of water, phosphate buffer, and DPIP. It will be used to prove that the three element of the solution do affect the results- it is strictly the chloroplasts that are subjected to the light/dark conditions.
Requirements for Test Tube Set Up
Data Collected During Time Intervals
Photosynthetic Rate for Light Reactions
0 5 10 15 20
Time Intervals
Photosynthetic Rate for Dark Reactions
0 5 10 15 20
Time Intervals
Results:
The results for the various conditions differed dramatically. As seen in the table, “Data Collected During Time Interval” the reference test tube remained at a trasmittance level of 100% for all five experimental tests. The control solution remained fairly constant for all five tests, but did vary slightly after the five minute time interval.
To test for this, DCIP (a chloroplast isolation buffer) was used to The hypothesis for this experiment was that the cell fraction in the cuvette marked P2 will have more chloroplast activity because it will exhibit greater color change and differences in the absorbance readings compared to the other cuvettes when exposed under the condition of light; moreover, this notion was believed to be so because the more a cell fraction is centrifuged, the more intact chloroplasts we’ll find (Leicht and McAllister, This meant that this cuvette (tested under light) should display a higher decrease in DCIP due to the reduction in absorbance (dependent variable) opposed to the other cell fractions tested depending on a sixteen minute period (independent variable). The overall goal was to provide proof, through data, that the cell fractions put under the light during the sixteen minute period would indicate a higher set of chloroplast activity versus the ones put in the
ABSTRACT: Chloroplasts carry out photosynthetic processes to meet the metabolic demands of plant cells (Alberts, 2008). They consist of an inner thylakoid membrane and a stroma. (Parent et. al, 2008).In this experiment we demonstrate the unique protein compositions of isolated thylakoid and stromal fractions from broken and whole spinach chloroplasts. Because these compartments carry out different metabolic processes, we confirm our hypothesis that performing SDS-PAGE on these fractions will result in distinct patterns on the gels. In isolating and analyzing nucleic acid from broken, whole, and crude chloroplast samples we demonstrate that genes for photosynthetic protein psbA are found in chloroplast DNA, while genes for photosynthetic enzyme
As the light is increased so would the rate of photosynthesis. Apparatus: boiling tube, 250ml beaker, bench lamp, ruler, sodium
Experiment #1: The purpose of this experiment is to investigate the effects of baking soda and light intensity on the rate of photosynthesis of green spinach leave through the observation of floating disk.
The Effect of Light Intensity on the Rate of Oxygen Production in a Plant While Photosynthesis is Taking Place
= > [CH2O} + O2 + H2O, This shows that when the light intensity is increased the rate of reaction will be more quicker he only anomalous result there was, is the one in the 100 watt result the reading after 5 minutes is anomalous because it does not follow the predicted pattern of increasing in the production of gas because it is lower I know from my own knowledge of photosynthesise that when the light intensity is increased the rate of reaction will be more quicker because many plants and trees photosynthesise quicker in stronger light and photosynthesise slower in dimly lit places. The chlorophyll absorbs light energy and enables it to be used by the plant for building up sugar. The overall effect is that energy is transferred from sunlight to sugar molecules.
Moreover, a future experiment is to determine the effect that the distance between the lamp and the solution has on the rate of photosynthesis. Several experiments with a similar setup to this experiment that vary the distances between the lamp and solution could be used to test this.
The Effect of Wavelength on Photosynthesis Rate Aim: To be able to To investigate how different wavelengths (colors) of light affect the photosynthetic rate of the synthetic. I will use a pant that is a pond weed called elodea. I will measure the rate of photosynthesis by measuring the amount of o2 given off in bubbles per minute from the elodea. I will do this by placing the Elodea in a test tube with sodium hydrogen. carbonate then I will vary the light wavelength (color) using colored.
The Effect of Light Intensity on Photosynthesis Of Elodea Canadensis Introduction I wanted to find out how much the light intensity affected the Photosynthesis in Elodea Camadensa. I decided to do this by measuring the amount of oxygen created during photosynthesis. Photosynthesis is the procedure all plants go through to make food. This process uses Carbon dioxide, water and light energy. It produces Oxygen and Glucose.
Investigating the Effect of Light Intensity on Photosynthesis in a Pondweed Aim: To investigate how the rate of photosynthesis changes at different light intensities, with a pondweed. Prediction: I predict that the oxygen bubbles will decrease when the lamp is further away from the measuring cylinder, because light intensity is a factor of photosynthesis. The plant may stop photosynthesising when the pondweed is at the furthest distance from the lamp (8cm). Without light, the plant will stop the photosynthesising process, because, light is a limited factor. However once a particular light intensity is reached the rate of photosynthesis stays constant, even if the light intensity is the greatest.
There is also the potential of human error within this experiment for example finding the meniscus is important to get an accurate amount using the graduated pipettes and burettes. There is a possibility that at one point in the experiment a chemical was measured inaccurately affecting the results. To resolve this, the experiment should have been repeated three times.
Photosynthesis will occur at a faster rate when the plant is exposed to the sun, than when it is not exposed to sunlight.
This is the same if there is the light intensity is too high as this can damage the chloroplasts in plants and this will minimize the rate of photosynthesis. As shown in the graph as the light intensity increases, the photosynthesis rate increases until a point is reached where the rate begins to level off into a plateau. At a low light intensity, photosynthesis occurs slowly because only a small quantity of ATP and NADPH is produced. As the light intensity shown in the graph is gradually increasing, more ATP and NADPH (NADH is used in cellular respiration and NADPH is used in photosynthesis) are produced, which means more oxygen and sugar is produced, therefore increasing the rate of photosynthesis. But as the light intensity increases even more and past a certain light intensity on the graph, this is due to the other factors such as carbon dioxide limiting the rate of
The Effect of Light Intensity on the Rate of Photosynthesis in an Aquatic Plant Introduction The input variable I will be investigating is light, as light is just one of the 4 factors required in the green-plant process of photosynthesis. Photosynthesis is the process by which green-plants use sunlight, carbon dioxide, water & chlorophyll to produce their own food source. This process is also affected by the temperature surrounding the plant (the species of plant we experimented with, pond weed, photosynthesised best at around 20 degrees centigrade.) Light, temperature & CO2 are known as limiting factors, and each is as important as the next in photosynthesis. Light is the factor that is linked with chlorophyll, a green pigment stored in chloroplasts found in the palisade cells, in the upper layer of leaves.
There will be a maximum level of photosynthesis. during the experiment, it is called a limiting factor. This factor will prevent the rate of photosynthesis from rising above a certain level. even if the conditions are improved to meet the best requirements for photosynthesis. The adage Variables Input - Light intensity is to be varied by increasing and decreasing.