| MadSci Network: Botany |
To avoid confusion with respiration or breathing, it is best to use the term cellular respiration. Cellular respiration is basically the same in both plants and animals. Both plant and animal cells have mitochondria, which is where cellular respiration occurs. The glucose is disassembled via glycolysis and the Krebs Cycle into carbon dioxide and water. Glycolysis and the Krebs Cycle also produce chemical energy in the form of ATP and NADH2. Most plants have some cells capable of photosynthesis, which allows them to form carbohydrates from carbon dioxide and water using light as the energy source. A small percentage of plants are parasitic and do not photosynthesize. They "steal" organic compounds from other plants, but still conduct cellular respiration. Many plant cells, as in roots and underground storage organs, such as tubers and rhizomes, do not photosynthesize so depend completely on cellular respiration for energy. Plants are also able to synthesize all the organic compounds they need, including fats, amino acids, proteins, carbohydrates, nucleic acids, vitamins, hormones and antiherbivore compounds. Animals cannot use light as their energy source so they eat plants or other animals to get organic compounds that they take apart in cellular respiration to obtain their energy. Animals also must eat other organisms to get the essential organic compounds they cannot synthesize, such as vitamins, certain amino acids and certain fatty acids. A common misconception is that plants conduct cellular respiration at night and photosynthesize during the day. In reality plants undergo cellular respiration continuously. Another common misconception is that photosynthetic reactions is simply cellular respiration running in reverse. The reactions are entirely different but the products and reactants are basically opposite. Photosynthesis occurs in chloroplasts and uses carbon dioxide and water to create carbohydrates and oxygen gas. Cellular repiration occurs in mitochondria and requires oxygen and carbohydrates and produces carbon dioxide and water. References Glycolysis Animated Krebs Cycle Re: Do plants use oxygen?
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