Determining Photosynthetic Pigments using Chromatography and Spectrophotometry Photosynthesis is a widely studied topic among the world of science due to its importance for life and its many uses. Photosynthetic pigments reflect and absorb different wavelengths of visible light based off their polarity. In this experiment, we studied photosynthetic pigments, first, by determining polarity and then, by measuring the amount of light of a given wavelength that a pigment absorbs. We used two methods in this experiment, chromatography and spectrophotometry. For the first portion of our experiment we determined the distance each pigment migrated, their R_f values, and their polarity. Our predications based off polarity, lead to our hypothesis …show more content…
Photosynthesis is, “the process by which plants convert light energy from the Sun into chemical energy in the form of carbohydrates” thus producing, “food for all living organisms, directly or indirectly” (Zheng). Photosynthesis has been examined in thousands of different ways. Many of these experiments include studying the rate of photosynthesis and pigment accumulation by obtaining plants and then stressing their light and nutrient intake (Okunlola and Adekunle). Photosynthetic pigments reflect and absorb different wavelengths of visible light based off their polarity. In this experiment, we studied photosynthetic pigments, first, by determining polarity and then, by measuring the amount of light of a given wavelength that a pigment absorbs. We used two methods in this experiment, chromatography and spectrophotometry. Chromatography “is a method used to separate mixtures of substances into their components” (lab book) and spectrophotometry is the use of a spectrophotometer to measure transmittance of light through a liquid. We used our knowledge of polarity to predict that since the least polar pigments move the most, pigment 1 is chlorophyll b, pigment 2 is chlorophyll a, pigment 3 is an anthocyanin, pigment 4 is a xanthophyll, and since most polar pigments move the least, pigment 5 is …show more content…
The data from the chromatography portion of the experiment showed that the least polar of the pigments would travel the most and the most polar would travel the least; chlorophyll b was the most polar and carotene was the least polar. The spectrophotometric portion of our experiment support this as well by showing us what wavelengths the pigments reflected and absorbed. With any experiment, however, are there sources of error. One source of error with this experiment would include not cleaning the cuvettes before placing them in the spectrophotometer. The smallest fingerprints or particles can lead to an inaccurate transmittance reading. Also, not using the reference cuvette when changing wavelengths is a source of error because it will lead to an inaccurate reading. Sources of error when using the chromatography paper include, too much or too little time for the solvent to ascend up the paper and the possibility that the solvent level may be too high. When studying photosynthetic wavelengths and pigments, it is known that, depending on the plant, some pigments are absorbed during photosynthesis while others are not. Pigments absorb only the light energy that is necessary in carrying out photosynthesis. This knowledge can assist in determining what areas
... in the chloroplasts in some of their cells. Chlorophyll allows the energy in sunlight to drive chemical reactions. Chloroplasts act as energy transducers, converting light energy into chemical energy. So as the plant has more light the chlorophyll inside the chloroplasts can react faster absorbing in more light for food and energy.¡¨ So this shows my prediction was correct for in my experiment and shown in my result table and graph the more light intensity there is on a plant the higher the rate of my photosynthesis will be. My prediction is very close to what I said the results will be so my prediction was correct and has been proven to be correct in my result table, graph and now explained again in my conclusion.
The high rate of absorbance change in blue light in the chloroplast samples (Figure 1) can be attributed to its short wavelength that provides a high potential energy. A high rate of absorbance change is also observed in red light in the chloroplast samples (Figure 1), which can be accredited to the reaction centre’s preference for a wavelength of 680nm and 700nm – both of which fall within the red light range (Halliwell, 1984). Green light showed low rates of photosynthetic activity and difference in change in absorbance at 605nm in the chloroplast samples (Figure 1) as it is only weakly absorbed by pigments, and is mostly reflected. The percentage of absorption of blue or red light by plant leaves is about 90%, in comparison to the 70–80% absorbance in green light (Terashima et al, 2009). Yet despite the high absorbance and photosynthetic activity of blue light, hypocotyl elongation was suppressed and biomass production was induced (Johkan et al, 2012), which is caused by the absorption of blue light by the accessory pigments that do not transfer the absorbed energy efficiently to the chlorophyll, instead direction some of the energy to other pathways. On the other hand, all of the red light is absorbed by chlorophyll and used efficiently, thus inducing hypocotyl elongation and the expansion in leaf area (Johkan et al, 2012).
Theodor’s experiment was created in part to learn which wavelengths (colors) of light were most effective in carrying out photosynthesis and to prove that it occurs in chloroplast. The experiment was inspired by Theodor’s observation of aerobic bacteria. Theodor observed that aerobic bacteria would move towards the chloroplasts of green algae. Theodor hypothesized that the reason why the bacteria moved toward the chloroplasts was because the organelle generated oxygen via photosynthesis. If photosynthesis occurs in chloroplasts, then the bacteria would aggregate on the chloroplasts producing the most oxygen. Theodor’s experiment was essential because it demonstrated that chloroplasts were the site of photosynthesis. Furthermore,
The energy inside molecules is called chemical energy, so light energy is converted into chemical energy by the chlorophyll. I believe that the results are reliable enough to support the hypothesis, because the graph of results proves the hypothesis because the gradient of the curve increases with the increase of the light intensity. I think that the method used is reliable enough to support the prediction. Overall, both graphs and my results support my predictions fully. My idea that the rate of photosynthesis would increase with light intensity was comprehensively backed up by my results.
In this laboratory, the degree of absorbance for the pigments in a leaf sample were observed using mechanisms that involved pigment isolation from a leaf extract, obtaining wavelength measurements, and displaying the measurements on an absorption spectra.
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.
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.
[IMAGE]Carbon dioxide + water Light Energy glucose + oxygen Chlorophyll [IMAGE]6CO2 + 6H20 Light Energy C6 H12 O6 + 6O 2 Chlorophyll Photosynthesis occurs in the leaves of the plant in the palisade layer. Chlorophyll in the cells in the palisade layer absorb light for photosynthesis. The plant releases the oxygen created in photosynthesis back into the air but it uses or stores the glucose for energy, respiration, growth and repair. The leaves and plants are also specially adapted for photosynthesis in their structure and cell alignment. Preliminary Experiment Apparatus * Piece of Elodea Canadensis * Bulb * Voltmeter * Test tube * Beaker * Box *
Pigments produced by microorganisms has been used to dye fabrics of different types. Talaromyces verruculosus produce a red colored pigment which is suitable to dye cotton and is harmless. Pigments from microorganisms give different types of shades of a color. For instance; Janthinobacterium lividum produce a pigment which gives purplish-blue shade to different types of fabrics. Thermomyces produce a yellow pigment used to dye number of fabrics specifically silk. NP2 and NP$ strains of Streptomyces produce dark blue and red colored pigments. Among retaining dye of microbial strains cotton fabric were stained comparatively weak while acrylic and polyamide fibers stained strongly.
Photosynthesis is a series of light driven reactions that convert energy poor compounds such as carbon dioxide and water to energy rich sugars [1] such as glucose. The process generate an electron gradient across the membrane of a chloroplast, which is used for ATP synthesis, and simultaneously produces electrons used to make NADPH, using NADP+ as an energy carrier[2]. Crudely put, it is the method by which autotrophic plants make their own ‘food.’
An Experiment to Investigate the Effect of Light Intensity on the Rate of Photosynthesis. Introduction Photosynthetics take place in the chloroplasts of green plant cells. It can produce simple sugars using carbon dioxide and water causing the release of sugar and oxygen. The chemical equation of photosynthesis is: [ IMAGE ] 6CO 2 + 6H20 C 6 H12 O 6 + 6O2 It has been proven many times that plants need light to be able to photosynthesize, so you can say that without light the plant would neither photosynthesize nor survive.
The structure of chlorophyll involves a hydrophobic tail embedded in the thylakoid membrane which repels water and a porphyrin ring which is a ring of four pyrrols (C4H5N) surrounding a metal ion which absorbs the incoming light energy, in the case of chlorophyll the metal ion is magnesium (Mg2+.) The electrons within the porphyrin ring are delocalised so the molecule has the potential to easily and quickly lose and gain electrons making the structure of chlorophyll ideal for photosynthesis. Chlorophyll is the most abundant photosynthetic pigment, absorbing red and blue wavelengths and reflecting green wavelengths, meaning plants containing chlorophyll appear green. There are many types of chlorophyll, including chlorophyll a, b, c1, c2, d and f. Chlorophyll a is present in all photosynthetic organisms and is the most common pigment with the molecular formula C55H72MgN4O5. Chlorophyll b is found in plants with the molecular formula C55H70MgN4O6, it is less abundant than chlorophyll a. Chlorophyll a and b are often found together as they increase the wavelengths of light absorbed. Chlorophyll c1 (C35H30O5N4Mg) and c2 (C35H28O5N4Mg) are found in algae, they are accessory pigments and have a brown colour. Chlorophyll c is able to absorb yellow and green light (500-600nm) that chlorophyll a
The investigation was completed over a period of a week for a wide range in the results to base experimental conclusions. From the primary data obtained, the pattern of the results supported the hypothesis and followed the trends of the theory discussed earlier and also the reflection spectra (Figure 2). The vertical growth of height table and graph (Table 1 & Figure 3) demonstrates the effects isolated colours of light have on the vertical growth of plants via mung beans. In the experiment of this investigation, vertical growth of the specimens of mung beans under the different colours of light was measured in response to time in days. From the results collected, all the values were expected and assisted to validate the findings of secondary experiments conducted by previous researchers.
According to scientists, photosynthesis is “the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.” ("pho•to•syn•the•sis,")
We used a chromatogram to identify the pigments that each plant produced. In the last lab, we discussed how chemicals can be used as indicators and carbon dioxide is one chemical that was needed to be detected during photosynthesis in this specific lab. In the presence of light, plants used carbon dioxide and water to produce carbohydrate and oxygen during photosynthesis. One product of cellular respiration is carbon dioxide. Bromothymol blue was used to detect the carbon dioxide from the plant and if it was detected the solution should turn yellow. But this lab wasn’t all about detection, it was also about how different light conditions effected the photosynthetic rate of plants. The plant we used to determine the effects was Elodea. In class, we tested the plant under light, no light, and green light. As a result, the photosynthetic rates ended up being different than what was predicted. Overall, this lab helped me to understand how photosynthesis effects life on earth and how it is effected by different light