Photosynthesis and Respiration

1909 WordsNov 2, 20058 Pages
All organisms on earth depend on photosynthesis, in which light energy is used to make sugar and other food molecules from carbon dioxide and water. For example, plants and other photo-synthesizers need only energy from sunlight, carbon dioxide from air, and water from the soil to make the sugar glucose. Photosynthesis is the most important chemical process on earth because it provides food for virtually all organisms, not only for photo-synthesizers but for the organisms that eat them. Plants can capture the energy of the sun by a chemical process called photosynthesis. This chemical reaction can be described by the following simple equation: 6CO2 + 6H2O + light energy = C6H12O6 + 6O2 The product of photosynthesis is a carbohydrate,…show more content…
The CO2 is converted into malic acid and then converted back to CO2 during the day when light is present, thus producing sugars, while the stomata are closed and greatly reducing water loss. Plants convert the energy from light into simple sugars, such as glucose. This food may be converted back to water and carbon dioxide, releasing the stored energy through a process called respiration. This energy is required for growth in nearly all organisms. Simple sugars are also converted to other sugars and starches (carbohydrates) which may be transported to the stems and roots for use or storage, or they may be used as building blocks for more complex structures, e.g. oils, pigments, proteins, cell walls, etc. Photosynthesis is dependent on the availability of light. In other words, as sunlight increases in intensity photosynthesis increases. This results in greater food production. Many garden crops, such as tomatoes, respond best to maximum sunlight. Tomato production is cut drastically as light intensities drop. Only two or three varieties of "greenhouse" tomatoes will produce any fruit when sunlight is minimal in fall and spring. Water plays an important role in photosynthesis in several ways. First, it maintains a plant's turgor or the firmness or fullness of plant tissue. Turgor pressure in a cell can be compared to air in an inflated balloon. Water pressure or turgor is needed in plant cells to maintain shape and ensure
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