Where does light reactions take place? ...Where does dark reactions take place?
915097
Light reactions take place on the thykaloid membranes of the chloroplast. Light reaction requires light and water, and produces ATP and Oxygen. Dark reactions take place in the stroma (fluid that fills the chloroplast). It uses the ATP produced in light reactions to make glucose.
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Photosynthesis consist of two major parts, the light and the dark reactions. The light reactions can be further divided into cyclic and noncylic flow. In noncylic both NADPH and ATP are produced whereas in cyclic ATP is produced in high quanties. The dark reaction require ATP to produce organic compounds from CO2 and water.
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The small, dark region in the cell nucleus is indeed called the nucleolus.  It is thought to be the site of ribosome synthesis.
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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. \n\nPhotosynthesis 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!\n\nWe can write the overall reaction of this process as: \n\n6H2O + 6CO2 ----------> C6H12O6+ 6O2\nMost of us don't speak chemicalese, so the above chemical equation translates as:\n\nsix molecules of water plus six molecules of carbon dioxide produce one molecule of sugar plus six molecules of oxygen\n\n\nDiagram 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.\n\nLeaves and Leaf Structure | Back to Top\nPlants 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.\n\nThe 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.\n\n\nCross 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.\n\nWater 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.\nVirtually 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.
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Many chemical reactions release energy in the form of heat, light, or sound. These are exothermic reactions. Exothermic reactions may occur spontaneously and result in higher randomness or entropy (ÄS > 0) of the system. They are denoted by a negative heat flow (heat is lost to the surroundings) and decrease in enthalpy (ÄH < 0). In the lab, exothermic reactions produce heat or may even be explosive. \nThere are other chemical reactions that must absorb energy in order to proceed. These are endothermic reactions. Endothermic reactions cannot occur spontaneously. Work must be done in order to get these reactions to occur. When endothermic reactions absorb energy, a temperature drop is measured during the reaction. Endothermic reactions are characterized by positive heat flow (into the reaction) and an increase in enthalpy (+ÄH). \n\nExamples of Endothermic and Exothermic Processes \n\nPhotosynthesis is an example of an endothermic chemical reaction. \nIn this process, plants use the energy from the sun to convert carbon dioxide and water into glucose and oxygen. This reaction requires 15MJ of energy (sunlight) for every kilogram of glucose that is produced: \nsunlight + 6CO2(g) + H2O(l) = C6H12O6(aq) + 6O2(g) \n\nAn example of an exothermic reaction is the mixture of sodium and chlorine to yield table salt. This reaction produces 411 kJ of energy for each mole of salt that is produced:\n\nNa(s) + 0.5Cl2(s) = NaCl(s) \n\nEndothermic reactions take in energy from their surroundings\n\nDissolution of salt is endothermic because it takes energy from its surroundings not much but some.\n\nAs far as all salt types that is hard to say and you would have to do an experiment to find that out.
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The light reaction happens in the thylakoid membrane and converts light energy to chemical energy. This chemical reaction must, therefore, take place in the light. Chlorophyll and several other pigments such as beta-carotene are organized in clusters in the thylakoid membrane and are involved in the light reaction. Each of these differently-colored pigments can absorb a slightly different color of light and pass its energy to the central chlorphyll molecule to do photosynthesis. The central part of the chemical structure of a chlorophyll molecule is a porphyrin ring, which consists of several fused rings of carbon and nitrogen with a magnesium ion in the center.
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The reactants I believe are sunlight and carbon dioxide and the products are oxygen and water, I'm not 100% postive.
293050
Are you refering to Physical Responses, or Interation of mass structure?Nuclear reaction,chemical reaction...etc..
620358
Your photoreptors and your visual cortex cells randomly fire, it is background noise a bit like you get with a CCD camera. Also you may notice that if you put pressure on your eyeball (not too much!) you will see a bright spot - so photoreceptors respond to more that just light.\n\nI get this too and my vision is fine.
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I think I know where you're headed with this....\nIf you want a bit more detail on the relationship between light and neurotransmitters, Google this term:\nPineal Gland\nRead everything you can find.
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Or did you mean when light hits an object, rather than lightning?\n\nIn this case, it really depends on the composition of the object and the wavelength of the light.  Generally, some of the light is absorbed into the object in the form of energy, and some of it is reflected back.  For example, a white light shone onto a red postbox will absorb every colour within the white light except for the red wavelengths which will reflect and be seen, hence it appearing red.
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id say reactions can occur at any temperature above 0k. so 0.00000000000000000000000000000001K, the reaction would happen but really really really really relaly slowly. but thatz in theory. i have no clue bout pracitcally. i think the lowest temp theyve got to so far is either 4K or 0.6K. so ya.
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When O2 is exposed to lots of energy, you can get the reaction:\n\n3 O2 -> 2 O3\n\nWhere O3 is ozone.  Electrical activity (lightening) is typically the source for the energy.
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Photosynthesis uses the energy of light to make the sugar, glucose. A simple general equation for photosynthesis follows.\n\n6 CO2 + 12 H2O + light → C6H12O6 + 6 O2 + 6 H2O\nCarbon Dioxide + Water + Light energy → Glucose + Oxygen + Water\nPhotosynthesis occurs in two stages. In the first phase light-dependent reactions or photosynthetic reactions (also called the Light reactions) capture the energy of light and use it to make high-energy molecules. During the second phase, the light-independent reactions (also called the Calvin-Benson Cycle, and formerly known as the Dark Reactions) use the high-energy molecules to capture carbon dioxide (CO2) and make the precursors of glucose.\n\nIn the light-dependent reactions the pigment chlorophyll absorbs light and loses an electron that travels down an electron transport chain producing the high energy molecules NADPH and ATP. The chlorophyll molecule regains its electron by taking one from water, a process that releases oxygen gas.\n\nIn the Light-independent or dark reactions the enzyme RuBisCO captures CO2 from the atmosphere and in a complex process called the Calvin-Benson cycle releases 3-carbon sugars which are later combined to form glucose.\n\nPhotosynthesis may simply be defined as the conversion of light energy into chemical energy by living organisms. It is affected by its surroundings and the rate of photosynthesis is affected by the concentration of carbon dioxide, light intensity and the temperature.
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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. \n\n Photosynthesis takes place primarily in plant leaves, and little to none occurs in stems, etc. The parts of a typical leaf include the upper and lower epidermis, the mesophyll, the vascular bundle(s) (veins), and the stomates. The upper and lower epidermal cells do not have chloroplasts, thus photosynthesis does not occur there. They serve primarily as protection for the rest of the leaf. The stomates are holes which occur primarily in the lower epidermis and are for air exchange: they let CO2 in and O2 out. The vascular bundles or veins in a leaf are part of the plant's transportation system, moving water and nutrients around the plant as needed. The mesophyll cells have chloroplasts and this is where photosynthesis occurs.The parts of a chloroplast include the outer and inner membranes, intermembrane space, stroma, and thylakoids stacked in grana. The chlorophyll is built into the membranes of the thylakoids. \n\nChlorophyll looks green because it absorbs red and blue light, making these colors unavailable to be seen by our eyes. It is the green light which is NOT absorbed that finally reaches our eyes, making chlorophyll appear green. However, it is the energy from the red and blue light that are absorbed that is, thereby, able to be used to do photosynthesis. The green light we can see is not/cannot be absorbed by the plant, and thus cannot be used to do photosynthesis. \n\nThe overall chemical reaction involved in photosynthesis is: 6CO2 + 6H2O (+ light energy)  C6H12O6 + 6O2. This is the source of the O2 we breathe, and thus, a significant factor in the concerns about deforestation.\n\n  \n\n\nThere are two parts to photosynthesis: \n\nThe light reaction happens in the thylakoid membrane and converts light energy to chemical energy. This chemical reaction must, therefore, take place in the light. Chlorophyll and several other pigments such as beta-carotene are organized in clusters in the thylakoid membrane and are involved in the light reaction. Each of these differently-colored pigments can absorb a slightly different color of light and pass its energy to the central chlorphyll molecule to do photosynthesis. The central part of the chemical structure of a chlorophyll molecule is a porphyrin ring, which consists of several fused rings of carbon and nitrogen with a magnesium ion in the center. \n The energy harvested via the light reaction is stored by forming a chemical called ATP (adenosine triphosphate), a compound used by cells for energy storage. This chemical is made of the nucleotide adenine bonded to a ribose sugar, and that is bonded to three phosphate groups. This molecule is very similar to the building blocks for our DNA. \nThe dark reaction takes place in the stroma within the chloroplast, and converts CO2 to sugar. This reaction doesn't directly need light in order to occur, but it does need the products of the light reaction (ATP and another chemical called NADPH). The dark reaction involves a cycle called the Calvin cycle in which CO2 and energy from ATP are used to form sugar. Actually, notice that the first product of photosynthesis is a three-carbon compound called glyceraldehyde 3-phosphate. Almost immediately, two of these join to form a glucose molecule. \n\nMost plants put CO2 directly into the Calvin cycle. Thus the first stable organic compound formed is the glyceraldehyde 3-phosphate. Since that molecule contains three carbon atoms, these plants are called C3 plants. For all plants, hot summer weather increases the amount of water that evaporates from the plant. Plants lessen the amount of water that evaporates
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The right chemical reaction is as follow:\n      6CO2+12H2O+energy=C6H12O6+6O2+6H2O\nPlz do not get confused with this reaction\n     6CO2 + 6H2O + light (energy) --> C6H12O6 + 6O2\nBecause 1st one is latest one and you can't get in some conventional books.Later one is wrong.
405112
1. Photon hits photoreceptor.\n2. Signal is transduced from photoreceptor to bipolar cells, then to retinal ganglion cells.  There is some retinal processing that occurs that involves horizontal and amacrine cells.  \n3. Signal goes through optic nerve, which takes the signal out of the retina into the lateral geniculate nucleus (LGN).  \n4. Signal goes from the LGN to the visual cortex, where the signal is further processed.  \n\nThat's really brief, but I hope that helps!