Photosynthesis & Respiration Advantages

Photosynthesis

• Photosynthesis comes from the Greek words for "light" and "putting together." Plants, algae and some bacteria use this process, which takes the energy from the sun to convert carbon dioxide into organic carbon compounds. These organic compounds can then be used by the plant as energy. Photosynthesis generally requires a special type of organelle called a chloroplast. Filled with chlorophyll, these little green organelles absorb red and blue light, converting it into a chemical called adenosine triphosphate, or ATP. The ATP is then used in conjunction with carbon dioxide to create sugars, like glucose.

Advantages of Photosynthesis

• Photosynthetic organisms have several advantages. For one, they do not need to go hunt for food -- it comes to them in the form of sunlight and air. In fact, photosynthetic organisms are sometimes called photoautotrophs, meaning that they make their own food. Moreover, their food is readily available -- the sun is a renewable, more or less unending resource. Photosynthesis is also very efficient, although no energy conversion process is 100 percent efficient. It has allowed plants, algae and bacteria to thrive in a wide variety of climates because it is highly adaptable. In addition, photosynthesis offers advantages for non-photosynthetic organisms: It helps reduce the level of carbon dioxide in the air, and it gives us oxygen as a byproduct.

Cellular Respiration

• Most living species that do not use photosynthesis use cellular respiration. In cellular respiration, food molecules combine with oxygen to create ATP, carbon dioxide and water. Respiration occurs in two phases: the breaking down of glucose to pyruvic acid, called glycolysis, and the oxidation of the pyruvic acid. The latter phase is called the Krebs or Citric Acid Cycle, and it takes place inside the mitochondria of the cells. Some organisms have evolved to perform anaerobic respiration, which does not require oxygen.

Advantages of Respiration

• While photosynthesis requires that light shine regularly, organisms that use cellular respiration can hunt down food when they need to. Their energy sources may have once been hard to find, but now food is relatively abundant, so they are not at the mercy of clouds and shade. Respiration also allows the organism to produce a considerable amount of energy at once, which is what allows animals to move around and is what allowed humans to develop such complex thought processes. Aerobic respiration is much more effective than anaerobic. Respiration also creates carbon dioxide for the photosynthetic organisms to use.