Introduction
Photosynthesis is a process done by photoautotrophs to convert inorganic compounds and light energy to organic matter. In all photosynthetic organisms, organic pigments exist to harvest the light energy. The three major classes of pigments are chlorophylls (green pigments) and carotenoids (yellow or orange pigments) which are lipophilic and associated in Chl-protein complexes as well as phycobilins that are hydrophilic. All chlorophylls (a, b, c and d) have two major absorption bands: blue or blue-green (450 or 475 nm) and red (630-675 nm). Chl a is present in all oxygenic photoautotrophs as part of the core and reaction centre pigment-protein complexes, and in light-harvesting antennae, it is accompanied by Chl b or Chl c. The accessory (antennae) pigments Chl b, c and d extend the range of light absorption. Carotenoids, a large group of biological chromophores, with an absorption range of 400-550 nm, have several roles in photosynthesic apparatus, such as being accessory light-harvesting pigments transferring excitation to Chl a, structural entities within the light-harvesting and reaction center pigment-protein complexes, and molecules required in the protection against excess irradiance. There are different types of microalgae, however only Chlorella sp. and Spirulina sp. are considered in the experiment as follows:
Chlorella sp. a green microalgae come from Chlorophyta division, or green algae, which embrace a large group of organisms with a great morphological variability, ranging from microscopic to macroscopic forms. Classes in Chlorophyta division have chlorophyll a and b and several carotenoids, that may be synthesized and accumulated outside the chloroplast under conditions of nitrogen deficiency and/or...
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...c microorganisms grow inside the flask due to the human errors, led to the possible later decrease in PAR*Y value after complete reduction of PSII.
Conclusion
Comparing the values of specific growth rates in six different growth and nutritional conditions (see table ), Chlorella sp. growing mixotrophically in light condition, supplied with acetate, shows the highest specific growth rate, after which Chlorella sp. growing heterotrophically in dark condition and supplied with acetate, and Spirulina sp. growing mixotrophically with acetate as the supplement are the second and the third highest in specific growth rate, respectively. Therefore, a mixed autotrophic and heterotrophic (mixotrophic) culture is preferable, however a heterotrophic culture is still suitable to both Chlorella sp. and Spirulina sp. showing a faster growth rate compared to autotrophic cultures.
Photosynthetic pigments work by absorbing different wavelengths of light and reflecting others. These pigments are divided into two categories primary (chlorophyll) and accessory (carotenoids) pigments. Chlorophyll is then divided into three forms a, b, and c (Campbell, 1996). Chlorophyll a is the primary pigment used during photosynthesis (Campbell, 1996). This pigment is the only one that can directly participate in light reactions (Campbell, 1996). Chlorophyll a absorbs the wavelengths of 600 to 700nm (red and orange) along with 400 to 500nm (blue and violet) and reflects green wavelengths (Lewis, 2004). Chlorophyll b has only a slight difference in its structure that causes it to have a different absorption spectra (Campbell, 2004). The carotenoid involved with spinach leaf photosynthesis absorbs the wavelengths of 460 to 550nm (Lewis, 2004). The pigments are carotene and its oxidized derivative xanthophylls (Nishio, 2000). A wavelength is determined by measuring from the crest of one wave to the crest of the next wave. All the wavelengths possible are...
... 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 greater overall rate of absorbance change in all chloroplast samples (Figure 1) confirms role of chloroplasts’ in photosynthesis. However, the use of the supernatant sample as a negative control was expected to yield no activity, which was shown to be untrue (Figure 1) and is contributed to the contamination of the supernatant sample with chloroplast. The fragile envelope of the chloroplasts can be eas...
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.
Autotrophs, can build organic compounds from simple molecules such as water and carbon dioxide and their type of feeding is called autotrophic nutrition. While they are building complex molecules, they need large amounts of energy. They are divided into two groups according to their source of energy: chemoautotrophs and photoautotrophs. Chemoautotrophs can synthesize organic compounds from CO₂ AND H₂O by using inorganic oxidation energy and they do not require sunlight. However, photoautotrophs, including green plants, produce sugar and O₂ from CO₂ and H₂O by using sunlight. The green pigment which absorbs the light is called chlorophyll and this process is called photosynthesis.
The process of photosynthesis is present in both prokaryotic and eukaryotic cells and is the process in which cells transform energy in the form of light from the sun into chemical energy in the form of organic compounds and gaseous oxygen (See Equation Below). In photosynthesis, water is oxidized to gaseous oxygen and carbon dioxide is reduced to glucose. Furthermore, photosynthesis is an anabolic process, or in other words is a metabolism that is associated with the construction of large molecules such as glucose. The process of photosynthesis occurs in two steps: light reactions and the Calvin cycle. The light reactions of photosynthesis take place in the thylakoid membrane and use the energy from the sun to produce ATP and NADPH2. The Calvin cycle takes place in the stroma of the chloroplast and consumes ATP and NADPH2 to reduce carbon dioxide to a sugar.
...hemical energy from cyanobacteria (the only bacteria that can perform photosynthesis) 2.4 billion years ago (Wernergreen). The first chloroplast came into being about one billion years ago when a single-celled protist and a cyanobacterium came together through endosymbiosis, and this first photosynthesizing eukaryotic lineage was the ancestor of land plants, green algae, and red algae. Cyanobacteria and algae endosymbionts have spread photosynthetic capabilities in such a broad range (Wernergreen). In other words, heterotrophic prokaryote cells had taken in autotrophic photosynthetic bacteria cells. The ingested cell continued to provide glucose and oxygen by photosynthesis. The host cell protected as well as provided carbon dioxide and nitrogen for the engulfed cell and overtime both cells lost the aptitude to survive without each other (Weber and Osteryoung).
Short version: Photosystem II is one of two light-capturing units in a chloroplast 's thylakoid membrane. Photosystem I absorbs photons of wavelength of 680 nm. Light energy is captured by chlorophyll and transferred into high energy electrons; Water is broken up into Oxygen and Hydrogen Ions and Electrons; Electrons are sent to electron transport chain.
[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 *
All eukaryotic plant cells that have coloured plastids contain their photosynthetic pigments in these membrane bound units [3]. In land plants, the facilitators of photosynthesis are the chloroplasts.
“Photosynthesis (literally, “synthesis from light”) is a metabolic process by which the energy of sunlight is captured and used to convert carbon dioxide (CO2) and water (H2O) into carbohydrates (which is represented as a six-carbon sugar, C6H12O6) and oxygen gas (O2)” (BioPortal, n.d., p. 190).
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
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.
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.