Search results
Results from the WOW.Com Content Network
Gas exchange is the physical process by which gases move passively by diffusion across a surface. For example, this surface might be the air/water interface of a water body, the surface of a gas bubble in a liquid, a gas-permeable membrane, or a biological membrane that forms the boundary between an organism and its extracellular environment.
In physiology, respiration is the transport of oxygen from the outside environment to the cells within tissues, and the removal of carbon dioxide in the opposite direction to the environment by a respiratory system. [1]
The oxygen tension (or partial pressure) remains close to 13–14 kPa (about 100 mm Hg), and that of carbon dioxide very close to 5.3 kPa (or 40 mm Hg). This contrasts with composition of the dry outside air at sea level, where the partial pressure of oxygen is 21 kPa (or 160 mm Hg) and that of carbon dioxide 0.04 kPa (or 0.3 mmHg). [6]
The atmosphere is 21% oxygen by volume, which equates to a total of roughly 34 × 10 18 mol of oxygen. [2] Other oxygen-containing molecules in the atmosphere include ozone (O 3), carbon dioxide (CO 2), water vapor (H 2 O), and sulphur and nitrogen oxides (SO 2, NO, N 2 O, etc.).
The concentration of carbon dioxide (CO 2) rises in the blood when the metabolic use of oxygen (O 2), and the production of CO 2 is increased during, for example, exercise. The CO 2 in the blood is transported largely as bicarbonate (HCO 3 − ) ions, by conversion first to carbonic acid (H 2 CO 3 ), by the enzyme carbonic anhydrase , and then ...
Aerobic respiration requires oxygen (O 2) in order to create ATP.Although carbohydrates, fats and proteins are consumed as reactants, aerobic respiration is the preferred method of pyruvate production in glycolysis, and requires pyruvate be transported the mitochondria in order to be oxidized by the citric acid cycle.
A breathing gas is a mixture of gaseous chemical elements and compounds used for respiration. Air is the most common and only natural breathing gas. Other mixtures of gases, or pure oxygen, are also used in breathing equipment and enclosed habitats such as scuba equipment, surface supplied diving equipment, recompression chambers, high-altitude mountaineering, high-flying aircraft, submarines ...
[106] [107] Blood or air with a high oxygen content is shown in red; oxygen-poor air or blood is shown in various shades of purple-blue. The lungs of birds are relatively small, but are connected to eight or nine air sacs that extend through much of the body, and are in turn connected to air spaces within the bones.