Photosynthesis is the process of converting light energy to chemical energy and storing it in the bonds of sugar. This process occurs in plants and some algae (Kingdom Protista). Plants need only light energy, CO2, and H2O to make sugar. The process of photosynthesis takes place in the chloroplasts, specifically using chlorophyll, the green pigment involved in photosynthesis.
Photosynthesis is the process by which plants, some bacteria, and some protistans use the energy from sunlight to produce sugar, which cellular respiration converts into ATP, the "fuel" used by all living things. The conversion of unusable sunlight energy into usable chemical energy, is associated with the actions of the green pigment chlorophyll. Most of the time, the photosynthetic process uses water and releases the oxygen that we absolutely must have to stay alive. Oh yes, we need the food as well!
We can write the overall reaction of this process as:
6H2O + 6CO2 ----------> C6H12O6+ 6O2
Most of us don't speak chemicalese, so the above chemical equation translates as:
six molecules of water plus six molecules of carbon dioxide produce one molecule of sugar plus six molecules of oxygen
Diagram of a typical plant, showing the inputs and outputs of the photosynthetic process. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Leaves and Leaf Structure | Back to Top
Plants are the only photosynthetic organisms to have leaves (and not all plants have leaves). A leaf may be viewed as a solar collector crammed full of photosynthetic cells.
The raw materials of photosynthesis, water and carbon dioxide, enter the cells of the leaf, and the products of photosynthesis, sugar and oxygen, leave the leaf.
Cross section of a leaf, showing the anatomical features important to the study of photosynthesis: stoma, guard cell, mesophyll cells, and vein. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Water enters the root and is transported up to the leaves through specialized plant cells known as xylem (pronounces zigh-lem). Land plants must guard against drying out (desiccation) and so have evolved specialized structures known as stomata to allow gas to enter and leave the leaf. Carbon dioxide cannot pass through the protective waxy layer covering the leaf (cuticle), but it can enter the leaf through an opening (the stoma; plural = stomata; Greek for hole) flanked by two guard cells. Likewise, oxygen produced during photosynthesis can only pass out of the leaf through the opened stomata. Unfortunately for the plant, while these gases are moving between the inside and outside of the leaf, a great deal water is also lost. Cottonwood trees, for example, will lose 100 gallons of water per hour during hot desert days. Carbon dioxide enters single-celled and aquatic autotrophs through no specialized structures.
Virtually all oxygen in the atmosphere is thought to have been generated through the process of photosynthesis. Obviously, all respiring organisms (including plants) utilize this oxygen and produce CO2. Thus, photosynthesis and respiration are interlinked, with each process depending on the products of the other. The global amount of photosynthesis is on the order of a trillion kg of dry organic matter produced per day, and respiratory processes convert about the same amount of organic matter to CO2. A large part (probably the majority) of photosynthetic productivity occurs in open oceans, mostly by oxygenic prokaryotes. Without photosynthesis, the oxygen in the atmosphere would be depleted within several thousand years. It should be emphasized that plants respire just like any other higher organism, and that during the day this respiration is masked by a higher rate of photosynthesis.
2006-11-13 13:05:41
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answer #1
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answered by Anonymous
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There are a lot of details. Which ones do you want to know about? I'm sure you could Google "photosynthesis" and find a lot of website with all the details you would want or need.
2006-11-13 13:01:33
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answer #2
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answered by hcbiochem 7
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Type Photosynthesis on google or your favorite search engine, and you will every kind of information you need, but you could go to answers.com or wikipedia.org and type photosynthesis in the search box. The best info engines are these, they will help with almost every word you need to know about, and give very good and so much info that you could even use in 12th grade.
2006-11-13 13:05:45
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answer #3
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answered by The Calculus Alchemist 6
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Simple answer is that, photosynthesis are energy converter for plants.
2006-11-13 13:15:13
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answer #4
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answered by M.R.Palaniappa 2
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process in which green plants utilize the energy of sunlight to manufacture carbohydrates from carbon dioxide and water in the presence of chlorophyll. Some of the plants that lack chlorophyll, e.g., the Indian pipe, secure their nutrients from organic material, as do animals, and a few bacteria manufacture their own carbohydrates with hydrogen and energy obtained from inorganic compounds (e.g., hydrogen sulfide) in a process called chemosynthesis. However, the vast majority of plants contain chlorophyll–concentrated, in the higher land plants, in the leaves.
In these plants water is absorbed by the roots and carried to the leaves by the xylem, and carbon dioxide is obtained from air that enters the leaves through the stomata and diffuses to the cells containing chlorophyll. The green pigment chlorophyll is uniquely capable of converting the active energy of light into a latent form that can be stored (in food) and used when needed.
The Photosynthetic Process
The initial process in photosynthesis is the decomposition of water (H2O) into oxygen, which is released, and hydrogen; direct light is required for this process. The hydrogen and the carbon and oxygen of carbon dioxide (CO2) are then converted into a series of increasingly complex compounds that result finally in a stable organic compound, glucose (C6H12O6), and water. This phase of photosynthesis utilizes stored energy and therefore can proceed in the dark. The simplified equation used to represent this overall process is 6CO2+12H2O+energy=C6H12O6+6O2+6H2O. In general, the results of this process are the reverse of those in respiration, in which carbohydrates are oxidized to release energy, with the production of carbon dioxide and water.
The intermediary reactions before glucose is formed involve several enzymes, which react with the coenzyme ATP (adenosine triphosphate) to produce various molecules. Studies using radioactive carbon have indicated that among the intermediate products are three-carbon molecules from which acids and amino acids, as well as glucose, are derived. This suggests that fats and proteins are also products of photosynthesis. The main product, glucose, is the fundamental building block of carbohydrates (e.g., sugars, starches, and cellulose). The water-soluble sugars (e.g., sucrose and maltose) are used for immediate energy. The insoluble starches are stored as tiny granules in various parts of the plant–chiefly the leaves, roots (including tubers), and fruits–and can be broken down again when energy is needed. Cellulose is used to build the rigid cell walls that are the principal supporting structure of plants.
2006-11-13 13:10:36
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answer #5
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answered by Crystal L 1
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I am going to make this as simple as I can.
The process in which using the sun to make sugar in plants.
2006-11-13 15:17:50
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answer #6
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answered by Kat 2
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someething like the cells in the plant get the glucose and turn into energy...long and complicated project...as this other one says, use google it will give you the answer
2006-11-13 13:03:17
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answer #7
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answered by xombiecats 2
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