A nonmetallic element with atomic symbol C, atomic number 6, and atomic weight [12.0096; 12.0116]. It may occur as several different allotropes including DIAMOND; CHARCOAL; and GRAPHITE; and as SOOT from incompletely burned fuel.
A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.
Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.
A mass of organic or inorganic solid fragmented material, or the solid fragment itself, that comes from the weathering of rock and is carried by, suspended in, or dropped by air, water, or ice. It refers also to a mass that is accumulated by any other natural agent and that forms in layers on the earth's surface, such as sand, gravel, silt, mud, fill, or loess. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1689)
A genus of gram-negative, aerobic, rod-shaped bacteria found in wet soil containing decaying organic material and in water. Cells tend to be pleomorphic if grown on media containing succinate or coccoid if grown in the presence of an alcohol as the sole carbon source. (From Bergey's Manual of Determinative Bacteriology, 9th ed)
The ash, dust, gases, and lava released by volcanic explosion. The gases are volatile matter composed principally of about 90% water vapor, and carbon dioxide, sulfur dioxide, hydrogen, carbon monoxide, and nitrogen. The ash or dust is pyroclastic ejecta and lava is molten extrusive material consisting mainly of magnesium silicate. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The simplest saturated hydrocarbon. It is a colorless, flammable gas, slightly soluble in water. It is one of the chief constituents of natural gas and is formed in the decomposition of organic matter. (Grant & Hackh's Chemical Dictionary, 5th ed)
The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)
Carbon monoxide (CO). A poisonous colorless, odorless, tasteless gas. It combines with hemoglobin to form carboxyhemoglobin, which has no oxygen carrying capacity. The resultant oxygen deprivation causes headache, dizziness, decreased pulse and respiratory rates, unconsciousness, and death. (From Merck Index, 11th ed)
The cycle by which the element carbon is exchanged between organic matter and the earth's physical environment.
Nanometer-sized tubes composed mainly of CARBON. Such nanotubes are used as probes for high-resolution structural and chemical imaging of biomolecules with ATOMIC FORCE MICROSCOPY.
Carbon Compounds, Inorganic
Inorganic compounds that contain carbon as an integral part of the molecule but are not derived from hydrocarbons.
The 17-alpha isomer of TESTOSTERONE, derived from PREGNENOLONE via the delta5-steroid pathway, and via 5-androstene-3-beta,17-alpha-diol. Epitestosterone acts as an antiandrogen in various target tissues. The ratio between testosterone/epitestosterone is used to monitor anabolic drug abuse.
A plant genus of the family RHAMNACEAE. Several species have been reclassified to the FRANGULA genus. It is often called buckthorn but should not be confused with other plants called that.
A genus of rod-shaped, oval, or bean-shaped bacteria found in soil and fresh water. Polar prosthecae are present and cells reproduce by budding at the tips of the prosthecae. Cells of this genus are aerobic and grow best with one-carbon compounds. (From Bergey's Manual of Determinative Bacteriology, 9th ed)
Doping in Sports
Oceans and Seas
A great expanse of continuous bodies of salt water which together cover more than 70 percent of the earth's surface. Seas may be partially or entirely enclosed by land, and are smaller than the five oceans (Atlantic, Pacific, Indian, Arctic, and Antarctic).
A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Stable zinc atoms that have the same atomic number as the element zinc, but differ in atomic weight. Zn-66-68, and 70 are stable zinc isotopes.
Gas Chromatography-Mass Spectrometry
A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.
The unconsolidated mineral or organic matter on the surface of the earth that serves as a natural medium for the growth of land plants.
Water particles that fall from the ATMOSPHERE.
Stable sulfur atoms that have the same atomic number as the element sulfur, but differ in atomic weight. S-33, 34, and 36 are stable sulfur isotopes.
Water containing no significant amounts of salts, such as water from RIVERS and LAKES.
A carboxy-lyase that plays a key role in photosynthetic carbon assimilation in the CALVIN-BENSON CYCLE by catalyzing the formation of 3-phosphoglycerate from ribulose 1,5-biphosphate and CARBON DIOXIDE. It can also utilize OXYGEN as a substrate to catalyze the synthesis of 2-phosphoglycolate and 3-phosphoglycerate in a process referred to as photorespiration.
Carbon Monoxide Poisoning
Deuterium. The stable isotope of hydrogen. It has one neutron and one proton in the nucleus.
Woody, usually tall, perennial higher plants (Angiosperms, Gymnosperms, and some Pterophyta) having usually a main stem and numerous branches.
Stable iron atoms that have the same atomic number as the element iron, but differ in atomic weight. Fe-54, 57, and 58 are stable iron isotopes.
Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.
Stable strontium atoms that have the same atomic number as the element strontium, but differ in the atomic weight. Sr-84, 86, 87, and 88 are the stable strontium isotopes.
One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.
The complete absence, or (loosely) the paucity, of gaseous or dissolved elemental oxygen in a given place or environment. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Radioisotope Dilution Technique
Method for assessing flow through a system by injection of a known quantity of radionuclide into the system and monitoring its concentration over time at a specific point in the system. (From Dorland, 28th ed)
Indicator Dilution Techniques
Methods for assessing flow through a system by injection of a known quantity of an indicator, such as a dye, radionuclide, or chilled liquid, into the system and monitoring its concentration over time at a specific point in the system. (From Dorland, 28th ed)
The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
Stable mercury atoms that have the same atomic number as the element mercury, but differ in atomic weight. Hg-196, 198-201, and 204 are stable mercury isotopes.
Magnetic Resonance Spectroscopy
A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.
A dark powdery deposit of unburned fuel residues, composed mainly of amorphous CARBON and some HYDROCARBONS, that accumulates in chimneys, automobile mufflers and other surfaces exposed to smoke. It is the product of incomplete combustion of carbon-rich organic fuels in low oxygen conditions. It is sometimes called lampblack or carbon black and is used in INK, in rubber tires, and to prepare CARBON NANOTUBES.