METABOLISM
What is metabolism?
All living things must have an unceasing supply of energy and matter. The transformation of this energy and matter within the body is called metabolism. Metabolism includes two different types: catabolism and anabolism. Catabolism is destructive metabolism. Typically, in catabolism, larger organic molecules are broken down into smaller constituents. This usually occurs with the release of energy. Anabolism is constructive metabolism. Typically, in anabolism, small precursor molecules are assembled into larger organic molecules. This always requires the input of energy. |
Cellular Respiration
Cellular respiration is a series of metabolic processes which all living cells use to produce energy in the form of ATP. In cellular respiration, the cell breaks down glucose to produce large amounts of energy in the form of ATP. Cellular respiration can take two paths: aerobic respiration or anaerobic respiration. Aerobic respiration occurs when oxygen is available, whereas anaerobic respiration occurs when oxygen is not available. |
Metabolism is a process of energy acquisition and conversion. It is necessary because organisms are constantly undergoing cellular changes--they are not in a state of equilibrium. Metabolism is an attempt to regulate cellular conditions by making internal changes to maintain a steady cellular state. As a general rule, nature's tendency is towards conditions of disorder. This means that disorderly conditions are energetically favorable--they release energy. Highly ordered and organized conditions are not energetically favorable and require energy to occur. As a result, the thousands of reactions that constantly occur inside us to maintain cellular organization need energy. The body produces this needed energy by breaking down ATP, and then using this energy to promote energetically unfavorable, but biologically necessary reactions.
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Interrelation of cellular respiration and photosynthesis
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What is the chemical equation for cellular respiration?
The overall (unbalanced) chemical equation for cellular respiration is: C6H12O6+O2→CO2+H2O+energy The balanced equation is C6H12O6+6O2→6CO2+6H2O+energy The equation expressed in words would be: glucose + oxygen → carbon dioxide + water + energy Cellular Respiration Equation (Products and Reactants) C6H12O6 + O2 → CO2 + H2O + ENERGY PRODUCTS REACTANTS PRODUCTS AND REACTANTS Where do they come from? Where do they go? The reactants as well as products of respiration are transported to and from the cell by the bloodstream, through processes like diffusion and osmosis. Oxygen enters the blood from air that animals inhale, through the alveoli and capillaries of the lungs. Carbon dioxide enters the bloodstream from the cells, transported to the lungs and exchanged there in the air only to be finally exhaled out. All these gas exchanges take place by diffusion, owing to difference in partial pressures of respective gases on the two sides of the transport medium. Water molecules are also transported out of the cell and are either recycled in to feed other physiological processes requiring water, or excreted/exhaled out of the body. The energy released in respiration is stored in the form of chemical energy in small denominations of ATP. |