Questions and Hypotheses
Experiment 1 Question: The main question that was addressed in the first experiment (Parts I and II) was which cell fraction had the most photosystem activity, which would be proportional to the number of chloroplasts present in the cell fraction. Photosystem activity is proportional to the number of chloroplasts since the photosystems are active in the thylakoid membranes of chloroplasts (Leicht and mcallister 2016). The amount of photosystem activity would be seen in the relative absorbance values for each cell fraction under the given light conditions. The absorbance would decrease as the DCIP electron acceptor (which is blue when oxidized) gets reduced (which is colorless). “The amount of color change is expected to be proportional to the number of functional photosystems, which in turn is proportional to the number of intact chloroplasts” (Leicht and mcallister 2016). We knew that chloroplasts were required for photosystem activity, but we
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Figure 3 shows the absorbance readings of P2 broccoli cell fraction under the following light conditions: white light, red light, blue light and green light. Based on the data in Figure 3, we can see that both red and blue light decreased in absorbance while green light had a slight change in absorbance. Figure 4 is related to Figure 3 because Figure 4 shows the total change in absorbance of each of the specific light conditions. The data from Figure 4 was calculated by finding the difference in the final (7 minutes) and initial (0 minutes) absorbance values for each of the light conditions in Figure 3. Based on the data in Figure 4, it can easily be seen that red light had a higher change in absorbance than blue light, and it can also be determined that green light had no decrease in absorbance. Compared to the positive control, red light had the most change in absorbance which means it had the most reduction of
If feeding efficiency and reproduction have a direct correlation, and a population started with equal proportions of individuals with each of three feeding types, metal spoon, metal knife, and plastic fork, the frequency of the population with metal spoons as their feeding structure will increase in the next generation. While the frequency of metal knifes and plastic forks will decrease. Furthermore, since the organisms with the metal spoon feeding structure have a higher fitness level, this population will evolve by natural selection to a point where the metal spoon phenotype will be in abundant. While the organisms with metal knifes and plastic forks phenotypes will decrease in frequency due to the lack of reproduction. Eventually, if this population persist overtime, most of the organisms, if not all, will have the metal spoon phenotype, while very few, if not any, will have the metal knife or the plastic fork phenotype.
Have you ever really wondered how different variables can affect how plants go through photosynthesis? Well, in this experiment, the purpose was to see how various environmental conditions can affect the overall photosynthetic capacity of a specific plant. The factors, light, darkness, cold, and heat were applied to see how the different components would affect the photosynthesis on spinach plants. Each group was given a different factor to test. Out group was given the light factor. The hypothesis for this experiment is that when adding light as a factor, the light will affect the overall plant photosynthesis.
The purpose of this lab is to observe the effect of white, green, and dark light on a photosynthetic plant using a volumeter and followed by the calculation of the net oxygen production using different wavelengths color of white and green light, and also the calculation of oxygen consumption under a dark environment, and finally the calculation of the gross oxygen production.
Photosynthesis is a vital process that requires to utilize energy for plants. This experiment was done to evaluate the effects of carbon availability on photosynthetic activity. The aquatic plant Elodea densa was placed into sodium bicarbonate solutions of five concentrations ranging from 0.1% to 1.0%, in five independent trials (excluding the negative control treatment of water). The temperature and light intensity was constant. The results indicated a directly proportional relationship between the availability of carbon dioxide and the rate of photosynthesis of Elodea Densa, as photosynthesis continued to increase with increasing amounts of bicarbonate. The most O2 amount of oxygen produced was with the 0.7% NaHCO3 concentration and least with the control of water. The null hypothesis that stated carbon concentration does not affect rate of photosynthesis of the aquatic plant was rejected. The predicted hypothesis that an increase in bicarbonate concentrations results in an increase in the photosynthetic rate was accepted. In conclusion, there is a significant increase in photosynthetic activity as the concentration of NaHCO3 increases.
Abstract: The purpose of this lab is to separate and identify pigments and other molecules within plant cells by a process called chromatography. We will also be measuring the rate of photosynthesis in isolated chloroplasts. Beta carotene, the most abundant carotene in plants, is carried along near the solvent front because it is very soluble in the solvent being used and because it forms no hydrogen bonds with cellulose. Xanthophyll is found further from the solvent font because it is less soluble in the solvent and has been slowed down by hydrogen bonding to the cellulose. Chlorophylls contain oxygen and nitrogen and are bound more tightly to the paper than the other pigments.
Based on your data, draw a conclusion regarding how light intensity affects the rate of photosynthesis.
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
We then acquired 6 test tubes and labeled three of them one through three. The other three were labeled 1L, 1S and 1K to determine which calibration used which chloroplast since each chloroplast solution had its own calibration tube. We filled each calibration tube with 1 mL of buffer, 4 mL of water, and 3 drops of the chloroplast designed for that specific test tube. After this we filled the other three test tubes with 1 mL of buffer, 3 mL of water, 1 mL of DPIP, and 3 drops of either the iceberg lettuce chloroplast, spinach or kale. The chloroplast must be put in last.
This experiment demonstrates the effects of pH on the rate of photosynthesis by examining the behavior of leaf disks in different pH solutions under light. In this experiment, we used five different pH levels: pH 5, pH 6, pH 7, pH 8 and pH 9. These solutions were created using a combination of hydrochloric acid and sodium hydroxide. Spinancia olcerea or spinach, leaves were used in the experiment to examine the effects of pH on the rate of photosynthesis. The rate of photosynthesis was measured by counting the number of leaf disks that rose to the surface of the solution after each minute. In acidic solutions, the rate of photosynthesis increased while in basic solutions, the rate of photosynthesis decreased.
We had three sets of ten spinach chads that were submerged in CO2 water and put under different wattages of light: forty, seventy-five, and one hundred . Chads under the forty wattage only had six rise out of ten, chads under the seventy-five wattage light had all ten rise, and chads under the one hundred wattage light had all ten rise under ten minutes.
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.
photosynthesis happens in two stages: light reaction and carbon fixation also known as calvin cycle.light reaction TAKES PLACE IN THYLAKOID USE light energy to produces atp and nadph whereas, calvin cycle takes place instroma uses energy derived from light dependent reaction to make GA3P from CO2 ( Bio166 lab execise manual, 2015). the purpose of this experiment was to separate plant
Chloroplasts are approximately 4 to 6 micrometers in diameter and shaped like a satellite dish with the concaves face toward the light. This shape, along with their alignment on the edge of the inner surface of the cell, maximizes their ability to capture light.
which serve as the bases for many related studies. In this experiment , the specimen of E. chlorotica were collected from salt marsh located at Martha Vineyartd., being starved for more than 2 months and kept at 10 °C with fluorescent light under 14:10 light-dark illumination cycle [40]. The RNA were extracted from E. chlorotica and transported to BGI in Hong Kong for analysis. Researchers have also sequenced the genome of V. litorea. E. chlorotica transcriptom were aligned with V. litorea as a reference source and detect for region of similarity between sequences by BLAST. Once matching sequencies in V. litorea were detected , BlastX algorithm were applied
Photosynthesis is a vital process that autotrophs use to transfer light energy into chemical energy. Photosynthesis ultimately produces O2 and glucose. It, like many other biological processes, can be affected by environmental variables. The variable that we altered in the following experiment are intensity, light wavelengths, and pigment types. In order to do this, we conducted three experiments. In the first experiment, we examined the effect of light intensity by placing vials with chloroplasts with DPIP at different light distances in which the results varied. Initially, 30cm away was the most effective for photosynthesis. Then 24cm appeared to be the most effective. Followed by 49cm at minutes 25 and 30. In the second experiment, we