Luis Ordonez
Sabarinath Sundaram
Section 531
Biology Lab 111
External Environmental Factors and Rate of Photosynthesis Abstract- In the first experiment we tested to see the affects that light intensity had on the rate of photosynthesis by creating different environmental conditions.We had hypothesized that the tubes left in the most intense light would have a faster rate of photosynthesis. This experiment resulted in the inhibited rate of photosynthesis when the photosynthetic environment was kept in the dark and wrapped in foil, while the environments that were exposed to light had a gradually increasing rate of photosynthesis as the light intensity of the external environments increased. In the second experiment we tested for the
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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. Tube 3 showed exponential decrease in the first 15 minutes of the experiment but not as drastically as Tube 1. Tube 4 showed a great amount of change, much like the other light-exposed tubes, but because it received the lowest intensity of light, its drop was not as …show more content…
The disks exposed to the green light and to the dark showed the least change in oxygen level and therefore the lowest amount of of photosynthesis occurred. This is most likely due to the fact that the pigment in spinach plants reflect green light instead of absorbing it and going through photosynthesis, and in the dark environment there was no light for the plants to absorb. The beakers placed in the red and blue light showed a greater amount of change than the dark and green light beakers, but they showed a very small amount of change when compared to the beaker in the white light. The white light wavelength was the best for catalyzing
The purpose of this experiment was to investigate the effects of light intensity on the rate of photosynthesis in a Moneywort plant. By observing the plant in distilled water mixed with sodium bicarbonate, different light bulbs were targeted onto the plant. The measurement of the amount of bubbles present on the plant during the trial of the experiment enabled us to identify the comparisons between the activity of the light and the process of photosynthesis.
Measuring the Rate Oxygen Production using an Oxygen Electrode Chamber in Photosynthesis of Spinacia oleracea with Varying Light Intensities
Test tube four contained a snail and was placed in the dark. It was hypothesized that the water would remain yellow after a day.
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
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
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.
Although, some factors that could have influenced this experiment was heat given off by the lamps, the restriction of the gas chamber, and how much CO2 there was in the chamber. Photosynthesis is also very heat sensitive, which is why when recording the O2 rates in the dark the lamp still needed to be on. The gas chamber restricted the flow of the natural environment along with already having a certain amount of CO2 in the chamber that wasn’t measured. These could have influenced the
Lumens are used to measure light intensity, so the higher number of lumens means the higher the intensity will be. The leaf chads will be placed in bicarbonate water, 10 in each beaker. There will be a total of two beakers. Both of the beakers should be placed the same distance from the light source that they are assigned to for more accurate results. The objective of this lab is to compare the rate of photosynthesis in the leaf chads by looking at the amount of light intensity.
The ravg for the experimental group was 0.1613 and the ravg for the control group was 0.2047. The results indicated that our predictions were correct; duckweed that received less light exhibited a lower rate of
The experiment is repeated twice and an average is obtained. This ensures the consistency of the measurement as the reading is triplicated, thus reducing anomalies. It can be seen that the reading obtained were around the same value. This proves that the results are reliable.
This lab was conducted to discover which level of light (measured in lux) would make Spinacia oleracea leaf disks float the fastest. Lux (lx) is latin for light, and is the unit of measurement for light in the International System of Units (Rouse 2011). Light plays a key role in the process of photosynthesis and in this we are essentially measuring the rate at which Spinacia oleracea leaf disks convert a bicarbonate solution into oxygen. The oxygen then would bubble up, allowing
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.
The ending result of this experiment confirms that as five test tubes are lined up with the varying level of absorbance, different results in the level of absorbance will appear as well, this is visible in above table. Thus, this is due to the varying amount of water in the solution. The blank sample had a 0.30 in its level of absorbance.
Measuring the Effect of Light Intensity on Photosynthesis Introduction Photosynthesis captures energy from sunlight. Plants, algae, and some bacteria use the energy captured during photosynthesis for their metabolic reactions. During photosynthesis in plants, chlorophyll and enzymes in leaves convert certain wavelengths of light into chemical energy. A simple equation can be used to represent photosynthesis. Enzymes and Chlorophyll light energy CO2 H2O carbohydrate O2
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