#respiration
- Abranchial — Lacking gills (the specialized respiratory organs of aquatic organisms); not possessing a branchial respiratory system, performing gas exchange either via lungs or directly through the cutaneous apparatus (skin); (of evolutionary stages) a phase in an organism's development where the aquatic respiratory apparatus has not yet formed or has completely atrophied.
- Aerobic — Living, developing, manifesting, or functioning only in the presence of free atmospheric oxygen. In biology, it refers to organisms (aerobionts) that use oxygen for cellular respiration; in physiology and sports, it describes a type of moderate and prolonged physical effort where energy is produced through oxygen metabolism.
- Aerobiosis — A life form or biological process that takes place exclusively in the presence of free molecular oxygen; a mode of cellular respiration characteristic of aerobic organisms, through which organic substances are completely oxidized to release usable chemical energy.
- Aerobiont — As a noun, it designates any organism (animal, plant, or microorganism) that lives, develops, and carries out its vital functions exclusively in the presence of free molecular oxygen from air or water. As an adjective, it describes the quality of an organism belonging to this ecological group strictly dependent on aerobic processes.
- Aerobiosis — A condition of life or a biochemical process of organisms that can only exist and function in the presence of free molecular oxygen; the assembly of metabolic reactions through which organic substances are fully oxidized, resulting in the production of energy, carbon dioxide, and water. It represents the opposite of anaerobiosis and is specific to the vast majority of complex living beings.
- Aerotonometry — An experimental method or clinical laboratory procedure used to determine and measure the tension or partial pressure of gases (oxygen, carbon dioxide) dissolved in biological fluids, especially in blood, by equilibrating them with a determined volume of air or gas mixture. This structural process provides essential data for evaluating respiratory function and alveolocapillary gas exchanges.
- Airozome — An extremely rare and niche scientific cytological term used to describe a hypothetical or modified intracellular vesicular structure, rich in enzymes or aerobic components, involved in microscopic transport mechanisms, cellular respiration, or metabolic adaptation in hyper-oxygenated environments. The concept is investigated in comparative cellular morphology studies to understand the compartmentalization of biochemical processes within advanced cytoplasmic organelles.
- Anaerobic — Said of organisms (bacteria, fungi) that can live, develop, or carry out their structural vital processes in the absence of free molecular oxygen; it also describes biochemical processes (fermentation, cellular respiration) taking place without the participation of oxygen. In sports physiology, it qualifies intense, short-duration physical efforts where energy is produced by breaking down carbohydrates without additional oxygen supply.
- Anaerobiotic — Pertaining to anaerobiosis or occurring under conditions completely devoid of oxygen; referring to anoxic metabolisms, organisms, or living environments. In a structural biochemical sense, it qualifies organic substance degradation reactions where the final electron acceptor is not molecular oxygen, but another chemical compound (such as nitrate or sulfate).