Gas exchange: Supply oxygen to aerobic tissues in the body and remove carbon dioxide as a waste product.
When you breathe, you are taking in oxygen with each inhale and releasing carbon dioxide with each exhale. This gas exchange is important for respiration, but while breathing is a physical process, respiration can be thought of as more of a chemical process. All organisms, from a single bacterial cell to a coral reef colony to a blue whale, undergo respiration.
In inhale process gases percentages are
Nitrogen : 78.028%
Oxygen : 21%
Carbon dioxide : 0.03%
In exhale process gases percentages are
Nitrogen : 78.028% (no change)
Oxygen : 16% (5% used)
Carbon dioxide : 4.4%
Food molecules absorbed after digestion are taken in, broken down, and the energy freed in the process is used to power the organism's movements and physiological functioning. Respiration is the biochemical process in which the cells of an organism obtain energy by combining oxygen and glucose, resulting in the release of carbon dioxide, water, and ATP, the currency of energy in cells.
In prokaryotic cells, respiration takes place in the cytosol and across the cell plasma membrane. In eukaryotic cells, it occurs in the cytosol and in the mitochondria. Mitochondria are the powerhouses of eukaryotic cells, and contain high surface areas of membrane folds on which respiration activity can be maximized.