Photosynthesis is a vital process used by plants, some protists, and cyanobacteria in which the light energy coming from the sun is transformed into chemical energy. Chemical energy, then, can be used for cellular processes and stored in the form of glucose, which is essential for life on earth since it fuels the metabolic process of cells (Morris & Moat, 2016, p.227). The purpose of this experiment is to separate and analyze photosynthetic pigments and determine the absorption spectrum of spinach leaves.
The process of photosynthesis can be shown by the following equation:
6CO2 + 6H2O + light C6H12O6 + 6O2
Photosynthesis occurs in a series of steps. First, the needed carbon dioxide enters a plant’s leaves through the pores in the
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This organelle contains several photosynthetic pigments that absorb light energy such as chlorophyll, which are the primary pigments involved in photosynthesis, and carotenes and xanthophylls. Photosynthesis would not be able to work if plants would not have such pigments. Each different pigment reflects a certain color of light and absorb other colors. The function and color absorption of each pigment is summarized in the table below.
Plant Pigment Function Color Absorption Color reflection
Chlorophyll a Principal chlorophyll; plays a significant role in the photosynthesis Blue-violet and red light Dark green
Chlorophyll b Transfers the light energy it absorbs to chlorophyll a Blue and orange light Light green
Carotenes Increase the overall absorbance of light energy by absorbing light that is not absorbed by the chlorophylls Mainly absorb blue-green light Orange
Xanthophylls
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Record this data in the Rf values table. Place the chlorophyll a (blue-green) from the chromatography paper into a small beaker and add 10 ml of acetone. Stir the mixture to dissolve chlorophyll a. Fill a cuvette with the dissolved chlorophyll A, and another cuvette with pure acetone. The cuvette with pure acetone will be used as the “blank”. Turn on the spectrophotometer Measure the absorbance of the chlorophyll a from 380 nm to 720 nm in an increment of 20 nm. Record the results in the Absorption Spectrum of Chlorophyll a table.
Careful note: Pour all of the liquids used in this experiment in a fume hood.
Results
Unfortunately, I was not able to attend to lab the day this experiment was conducted. However, if I would have, I would have plug the data found by measuring the paper chromatography in the table below. Moreover, I would have also plug the data from the spectrophotometer on the table in the next page.
Plant Pigment Distance traveled by pigment Distance traveled by solvent Rf Color
Chlorophyll a N/A N/A N/A Dark green/blue
Chlorophyll b N/A N/A N/A Light green
Carotenes N/A N/A N/A Orange red
Xanthophylls N/A N/A N/A
Increasing the light intensity will make photosynthesis faster. Variables: In this experiment there are a few things we have to keep the same.
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,
Both starch and sucrose can be converted back into glucose and used in respiration. Photosynthesis happens in the mesophyll cell of leaves. There are two kinds of mesophyll cells - palisade mesophyll and spongy mesophyll. The mesophyll cells contain tiny bodies called chloroplasts which contain a green chemical called chlorophyll.
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 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).
In this laboratory experiment, the rate of photosynthesis was measured through the use of the “floating leaf disk technique.” The leaf disks were placed into a syringe and the O2 and CO2 in the mesophyll layers of the leaves were removed and then replaced with sodium bicarbonate or water, causing the leaves to sink to the bottom of the container. If one determines the number of leaf disks rising to the top as a result of an increase in oxygen gas in the mesophyll cells, then the rate of photosynthesis is able to be measured because O2 is a product of photosynthesis. The first step of this experiment was a feasibility study of the variance in the photosynthetic activity of the leaf disks in both water and bicarbonate solutions. After five minutes of light exposure, all of the leaf disks in the bicarbonate solution (10 disks) had ...
[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 *
A cuvette was filled 3/ 4ths of the way and the absorbance measured in a spectrophotometer. The data was compiled as a class and recorded. The Spectrophotometer was blanked using a test tube of distilled water.
The substance that absorbs sunlight is chlorophyll, which is mainly contained in chloroplasts. This energy is used to convert carbon dioxide (CO2) and water into sugars. This conversion creates the waste product oxygen, which is used by humans for breathing. Without being able to photosynthesise plants will stop growing and die. In a plant growing in the dark the chlorophyll will slowly be destroyed causing them to use their food reserves.
Begin collecting samples with the pure hexane. Keep adding hexane so that the silica gel column does not run dry. Collect one 20 ml sample. Repeat with 90:10 hexane and collect 4 20-mL bottles. Repeat with 80:20 hexane and collect 2 20-mL samples.
Photosynthesis in simpler turns is the ability of a live plant to carry on its chemical process by the use of light energy. Photosynthesis can not take place when there is absolutely no light, instead it stores the light it captures during the day, and uses it when needed. Photosynthesis can take place in land plants and aquarian plants such as algae. There are many factors that influence the ability of a plant to go through photosynthesis, such as light, the color of light and amount of water and or light.
however it does not easily absorb green or yellow light, rather it. reflects it, this decreases the rate of photosynthesis. This can
Photosynthetic pigments are essential for life because they allow photosynthesis to occur by capturing sunlight which is then used alongside carbon dioxide and water to form organic compounds such as glucose and oxygen. The pigments allow the conversion of light energy to chemical energy which other organisms can benefit from. Oxygen is utilised by other organisms in aerobic respiration. The different pigments present in the chloroplasts allow a wide variety of wavelengths of light to be absorbed for efficient photosynthesis and provide colours to the plant to attract pollinators.
Photosynthesis is a process in plants that converts light energy into chemical energy, which is stored in bonds of sugar. The process occurs in the chloroplasts, using chlorophyll. Photosynthesis takes place in green leaves. Glucose is made from the raw materials, carbon dioxide, water, light energy and oxygen is given off as a waste product. In these light-dependent reactions, energy is used to split electrons from suitable substances such as water, producing oxygen. In plants, sugars are produced by a later sequence of light-independent reactions called th...
Photosynthesis is a process in which plants and other organisms convert the light energy from the sun or any other source into chemical energy that can be released to fuel an organism’s activities. During this reaction, carbon dioxide and water are converted into glucose and oxygen. This process takes place in leaf cells which contain chloroplasts and the reaction requires light energy from the sun, which is absorbed by a green substance called chlorophyll. The plants absorb the water through their roots from the earth and carbon dioxide through their leaves.