Photosynthesis and Cellular Respiration

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Photosynthesis and Cellular Respiration Daryl Waldron BIO/240 November 10, 2014 Tamu Crisden Photosynthesis and Cellular Respiration The cells of all organisms are capable in acquiring the energy necessary to fuel chemical reactions for growth, repair, survival, and reproduction. Photosynthesis and cellular respiration are the main pathways of energy flow in living organisms. Photosynthesis is a process by which plants and some other organisms convert, light energy from the sun, carbon dioxide from the air, and water from the earth into chemical energy stored in molecules like glucose. Cellular Respiration is the process in which glucose is broken down in the presence of oxygen to supply a cell with energy. In cellular respiration and photosynthesis, the reactants flow through pathways to become products in very different ways. Respiration is catabolic, breaking glucose down, while photosynthesis is an anabolic reaction, building glucose. Photosynthesis (carbon dioxide + water + light energy = glucose + oxygen + water) provides the basic energy source for nearly all living things. Plants use the glucose produced by photosynthesis to build leaves, flowers, fruits and seeds. Photosynthesis is broken down into two separate stages, the light-dependent reactions and light-independent reactions. In the light-dependent reaction, the chloroplast traps light energy from the sun and it is converted into ATP and NADPH energy. In the light-independent reaction, NADPH delivers the hydrogen and carbon dioxide atoms that help form glucose, and ATP donates energy to areas where glucose is put together from carbon. This process occurs in chlorophyll bearing cells. Chlorophyll is an amazing chemical that is the essential ingredient in photosynthesis. When photons of light hit chlorophyll, the electrons in the central magnesium atom donate an electron to a series of chemical
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