Chloroplasts Lab Report

In the blank cuvettes, the 2 mL of pH levels 2,5,7, and 10 were added first, followed by the 1mL of peroxidase. However our experimental cuvettes contained both hydrogen peroxide and guaiacol. Before the cuvettes were placed in the spectrophotometer we added 0.1 mL of H202, followed by 0.02 mL of guaiacol these two substances were added last immediately before they were placed in the spectrophotometer. Para film was placed over the cuvette opening, and the assay solution was shaken and placed into the spectrophotometer where its saturation level was then tested. We recorded the saturation level of the solution every 15 seconds for 3 minutes. This process was repeated two times for each pH level for a total of two trials.

The initial experiment was a success. As our treatment group spent more and more time under the lights, the absorbance rate continues to decrease toward zero. Once our 30 minutes were up, the absorbance rate in each tube was significantly lower than at the start of our experiment. In contrast the two control groups did significantly lower the absorbance. Each control lacked one of the vital aspects of photosynthesis, one being light, and the other being chloroplast. Neither of the control groups (Control 1 or 2) showed any signs of photosynthesis. Control 1 was exposed to light, but contained no photosynthetic organelles thus the absorbance throughout the 30 minutes varied minimally, mostly staying stagnant. Control two which contained chloroplast but was not exposed to any light failed to lower the absorbance at all and in fact increased the absorbance over the 30 minutes. However, the treatment group contained both and ultimately performed photosynthesis as we expect therefore, confirming our assumption that chloroplast were the organelles required for photosynthesis in plants and that light is required to perform said photosynthesis. The treatment group, containing both the chloroplast and being exposed to light provided evidence that photosynthesis was taking place as the absorbance lowered at each 10-minute interval. Having a less absorbance would be desired because as DCIP became reduced we would expect the solution to become more and more clear, thus less

Hypothesis for experiment 1: The hypothesis for experiment 1 was that cell fraction pellet 2 would contain the most chloroplasts. Figure 2C on page 43 in the lab notebook shows that centrifugation of a plant cell resulting in 3 pellets will result in the second pellet containing the most chloroplasts because it is lighter and less dense when compared to nuclei and amyloplasts but more dense than mitochondria(Mcallister and Leicht 43). We created 2 pellets so it would make sense that the last pellet will contain the most chloroplasts. Question for experiment 2: Using the cell fraction that was identified in the previous experiment as containing the most chloroplasts, how much effect will diuron, an herbicide used in Iowa, have on the electron transport chain?(Mcallister and Leicht

In the effect of light wavelength experiment, the action spectrum is used to demonstrate the effectiveness of various wavelengths of light on photosynthesis. To observe these effects of the wavelengths the wavelength pigments red, blue, green, white light, and no light are used. In the experiment, spinach leave disks were aspirated in a sodium bicarbonate solution in order to remove all internal gases and make the disks sink to the bottom of a beaker. Each beaker full of 10 spinach disks was placed into a different box with a different colored light source.

In this examination, four tubes of the chloroplast (Dark, 24cm, 30 cm, and 49 cm), buffer solution, water and DPIP were set in different strengths of light to decide how the light, powerful influences the reaction rate. The response rate was measured using absorbance values in five-minute increments. The tubes were put at 24 cm away, 30 cm away, 49 cm away, and totally dull. The tube nearest the light caused the smallest absorbance value, while the dim tube had the most astounding absorbance values. As the light power builds, the absorbance esteem and rate of the response diminished.

In Tube 1, which was held in a dark environment and wrapped in foil, was seen to have almost no change in absorbance relative to the other tubes. The lack of fluctuation in absorbance is a result of very little photosynthesis taking place. Tube 2, which had the most intense light, saw the greatest drop in absorbance in the first 15 minutes. This relatively rapid change in absorbance is a result of photosynthesis occurring more rapidly in this tube than in the others. Tube 3 was put in a similar environment but with less light intensity than in Tube 1 and further away from the lamp than in Tube 1.

The thylakoid is a membrane-bound compartment inside the cyanobacteria and chloroplasts. They are made up of thylakoid membrane surrounding a thylakoid lumen. Thylakoids that are in the chloroplasts are usually stacks of disks called grana or granum. The formation of thylakoids requires light (the sun.) If there were an absence of light and the seedlings grew in the dark, the undergo etiolation. Thylakoids don't develop and it literally kills the plant because its mouth for eating (metaphorically) was sewn together.

Eukaryotic organelles are very crucial to the function of living organism. Organelles such as the nucleus, mitochondria and chloroplast are named to the most important and valuable. The cell nucleus is a double membrane‐bound organelle that contains the hereditary data of the cell bundled as chromatin. The nucleus is a trademark highlight of most eukaryotic cells. (Wiley,2017) Eukaryotic cells are unique and important as it consists of a variety of different organelles. These organelles are: “mitochondria, chloroplasts, the endoplasmic reticulum, the Golgi apparatus, and lysosomes.” The specific organelles that have been mentioned are significant as they have their own job to function a cell. (Eukaryotic Cells | Learn Science at Scitable, 2017)

Some errors may have involved: not calibrating the tubes, not sealing the test tubes properly, or using inviable organisms. With the class’ results, the light dependent hypothesis was validated because oxygen output was highest in the presence of light and lower without it, while the varying colors light hypothesis remains unverified. Introduction Photosynthesis is “the conversion of the energy of solar photons to chemical energy by the oxidation of water to oxygen and the concomitant reduction of carbon dioxide to the equivalent of formaldehyde or sugars” (Photosynthetic Oxygen Production). The energy used in photosynthesis comes from solar photons, which are necessary for reducing and rearranging water and carbon dioxide (The Physiology of Photosynthesis).

An absorption spectra graph has 3 curves that show the wavelengths of the light best best absorbed by the 3 types of chloroplast pigments. Chlorophyll A works best with red or violet, chlorophyll B works best with orange and dark blue, and carotenoids work best with blues. The action spectra graph plots the

The predicted hypothesis for this experiment was Ulva grown under low light will have a higher chlorophyll a content and a higher chlorophyll b content than Ulva grown under high light. The reason that this assumption was made is because Ulva that is growing in light limiting areas need to be able to harvest as much light as possible while the light is available. Chlorophyll a is able to absorb light in the red and blue spectrum while chlorophyll b is able to absorb light at intermediate wavelengths, as discussed in the introduction. The T-tests results that were calculated concluded to be: chlorophyll a (0.17), chlorophyll b (0.47) and the total chlorophyll (0.37). Since all three p-values are greater than 0.05, it can be concluded that there is no difference between the low and high light means, therefore the predicted (alternate) hypothesis can be rejected. In theory the experiment should have resulted as the alternative hypothesis predicted, but consequently errors have occurred that have prevents this outcome. All the class data was combined, therefore nine replications were conducted which would have eliminated human error, but unfortunately the Ulva used mightn’t have been grown under the high and low light conditions for long enough for the chlorophyll to adapt to the

The initial absorbance of each B.vulgaris cube was measured immediately after the cubes had been placed in the solution and inverted. A cuvette containing a sample of the treatment was placed in the spectrophotometer, thus indicating the pigment intensity. The cuvette sample was returned to the treatment’s vial to maintain a consistent approximate volume. The inversion and sample collection process was repeated after 15 and 30 minutes with fresh cuvettes. Prior to measuring the absorbance of the treatment samples at each time interval, the spectrophotometer was zeroed. The mean absorbance of six replicates was calculated for each treatment sample at the tested time periods.

The purpose of the experiment was to determine the wavelength and light intensity effect on the reaction rate of photosynthesis. Photosynthesis is the conversion of light energy to chemical energy in the form of organic compounds. There are two phases in photosynthesis, the light reaction and dark reaction. The following experiment tested only the light reaction. Photosynthesis takes place on the chloroplast, and the chloroplast contains chlorophyll pigments which absorb light energy. Pigments are particular to different wavelengths. The following experiment helped determined the fastest photosynthetic reaction rate from wavelength ranging from 450, 545, 650, and 750 nm, and intensities 3, 7, 15, 35, and 150 uEinsteins/m^2/sec.

To understanding pigments in plants in relation to light, Thin Layer Chromatography (TLC) and spectroscopy are used to test the

In this experiment, the alternative hypothesis was supported by the results. The alternative hypothesis state that, the different colors of light will have an effect in spinach (Spinecea olerace), in the results session, it is visible that every color of the light has a measurable impact on the amount of energy that S. alerace absorbed. The colors that showed to have the biggest effect in Spinach was Red lite and white lite. The red light demonstrated to have the higher amount of energy that spinach can absorbs. The tube that showed the lowest amount of energy was the foil tube, because it was cover from any source of light. Also, this tube tested that plants that do not received light, like the foil tube, did not capture as many energy as