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Parts-per-million cube of relative abundance by mass of elements in an average adult human body down to 1 ppm. About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium.
Most biomolecules are organic compounds, and just four elements — oxygen, carbon, hydrogen, and nitrogen —make up 96% of the human body 's mass. But many other elements, such as the various biometals, are also present in small amounts. The uniformity of both specific types of molecules (the biomolecules) and of certain metabolic pathways ...
Bicarbonate buffer system. Carbon dioxide, a by-product of cellular respiration, is dissolved in the blood, where it is taken up by red blood cells and converted to carbonic acid by carbonic anhydrase. Most of the carbonic acid then dissociates to bicarbonate and hydrogen ions. The bicarbonate buffer system is an acid-base homeostatic mechanism ...
Cellular respiration. Typical eukaryotic cell. Cellular respiration is the process by which biological fuels are oxidized in the presence of an inorganic electron acceptor, such as oxygen, to drive the bulk production of adenosine triphosphate (ATP), which contains energy. Cellular respiration may be described as a set of metabolic reactions ...
Weak. v. t. e. Acid–base homeostasis is the homeostatic regulation of the pH of the body's extracellular fluid (ECF). [ 1 ] The proper balance between the acids and bases (i.e. the pH) in the ECF is crucial for the normal physiology of the body—and for cellular metabolism. [ 1 ] The pH of the intracellular fluid and the extracellular fluid ...
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body. MRI does not involve X-rays or the use of ionizing ...
For acidosis referring to acidity of the urine, see Renal tubular acidosis. Acidosis is a biological process producing hydrogen ions and increasing their concentration in blood or body fluids. pH is the negative log of hydrogen ion concentration and so it is decreased by a process of acidosis.
Biological roles of the elements. A large fraction of the chemical elements that occur naturally on the Earth's surface are essential to the structure and metabolism of living things. Four of these elements (hydrogen, carbon, nitrogen, and oxygen) are essential to every living thing and collectively make up 99% of the mass of protoplasm. [ 1 ]