Respiration is an essential and important process in all living organisms. It helps in the exchange of gases and provide oxygen which is very important for the survival of most of the life forms on earth. Respiration is something we all know about as it is a visible and regular process, one which we experience with every breath. Exhalation and inhalation are the two stages associated with respiration. Our body is in need of oxygen for survival which is available in the atmospheric air. During inhalation we breathe in the oxygen and expel out carbon dioxide during exhalation.
Respiration is a process which provides body with oxygen for growth and other metabolic activities and removes waste products in the form of carbon dioxide gas. The exchange of gases take place in the Lungs. The Lungs are the main organs involved in the respiration process. Air passes into the lungs through the process of inhalation through the nostrils and the air flows down the trachea into the lungs. The Lungs have alveoli which are small air sacs and is filled with tiny capillaries which are functional in the carrying of oxygen and carbondioxide back and forth from the heart to the lungs. Respiration process in plants and animals takes place differently thought he main goal is similar. The organs of respiration are different in living organisms based on their evolution, Some respire through skin such as earthworm, fish use gills while whales use both gills and lungs like mammals. Since the process occurs inside the cells, it is also called as cellular respiration. During this process, carbohydrates mainly the glucose is broken down and energy(ATP) is released. This energy is used by the cells for various functions and processes from muscle contraction to cell building, repair and growth.
The respiration process is carried out in two ways in living organisms:
Aerobic and Anaerobic.
Aerobic respiration: This is a very complex process and involves chemical reactions during which oxygen is made use of for converting glucose into carbon dioxide and H2O. In this process energy is generated in the form of ATP, which are the carriers of energy. The start and end of aerobic respiration is usually the same if the glucose is to be broken down. Although burning is a type of aerobic process, the energy released in it is heat. But in aerobic respiration the release of energy is done in controlled way and hence very less energy is wasted in the form of heat. Most of the energy thus released is utilized by cells for growth and other activities.
Anaerobic respiration: During this process glucose is broken down and energy, lactic acid or ethanols along with CO2 are released as the byproduct. This process is also known as fermentation. The anaerobic respiration is carried out in humans for only a short time. When the respiration has build up enough, muscles stop the production of lactic acid. But this process is extensively carried out in micro organisms like yeast which undergoes aerobic respiration when oxygen is present and in its absence respires anaerobically and creates alcohol.
Almost all the internal metabolic processes are carried out with the help of enzymes. Respiration gives out energy in the inside of the cells. During this process it makes use of around 70 different types of enzymes which act as catalyst. The energy release process is carried out in various stages and around 75% is released in the form of heat. The energy released is secreted by the cells in the form of ATP or adenosine triphosphate. In case of aerobic respiration, the glucose molecule is totally broken down for producing useful energy and waste products like H2O and CO2. This process can be shown in the form of word equation as given:
Glucose + oxygen -> carbon dioxide + water + energy
In case of anaerobic respiration, glucose molecules are broken only partially and the by product released are CO2 and ethanol or lactic acid. Its equation can be expressed as:
Glucose -> ethanol + carbon dioxide + energy
Glucose -> lactic acid + energy
These symbol equations can be expressed as:
C6H12O6 -> 2CO2 + 2CH3-CH2-OH (ethanol)
C6H12O6 -> 2C3H6O3 (lactic acid)