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Toxin (other)
A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. They occur especially as proteins, often conjugated. The term was first used by organic chemist Ludwig Brieger (1849–1919) and is derived from the word " toxic". Toxins can be small molecules, peptides, or proteins that are capable of causing disease on contact with or absorption by body tissues interacting with biological macromolecules such as enzymes or cellular receptors. They vary greatly in their toxicity, ranging from usually minor (such as a bee sting) to potentially fatal even at extremely low doses (such as botulinum toxin). Terminology Toxins are often distinguished from other chemical agents strictly based on their biological origin. Less strict understandings embrace naturally occurring non-organic toxins, such as arsenic. Other understandings embrace synthetic analogs of naturally occurring organic poisons as toxins, and may or may not embra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ingestion
Ingestion is the consumption of a substance by an organism. In animals, it normally is accomplished by taking in a substance through the mouth into the gastrointestinal tract, such as through eating or drinking. In single-celled organisms ingestion takes place by absorbing a substance through the cell membrane. Besides nutritional items, substances that may be ingested include medication (where ingestion is termed oral administration), recreational drugs, and substances considered inedible, such as foreign bodies or excrement. Ingestion is a common route taken by pathogenic organisms and poisons entering the body. Ingestion can also refer to a mechanism picking up something and making it enter an internal hollow of that mechanism, e.g. "''a grille was fitted to prevent the pump from ingesting driftwood''". Pathogens Some pathogens are transmitted via ingestion, including viruses, bacteria, and parasites. Most commonly, this takes place via the faecal-oral route. An intermedia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inhalation
Inhalation (or Inspiration) happens when air or other gases enter the lungs. Inhalation of air Inhalation of air, as part of the cycle of breathing, is a vital process for all human life. The process is autonomic (though there are exceptions in some disease states) and does not need conscious control or effort. However, breathing can be consciously controlled or interrupted (within limits). Breathing allows oxygen (which humans and a lot of other species need for survival) to enter the lungs, from where it can be absorbed into the bloodstream. Other substances – accidental Examples of accidental inhalation includes inhalation of water (e.g. in drowning), smoke, food, vomitus and less common foreign substances (e.g. tooth fragments, coins, batteries, small toy parts, needles). Other substances – deliberate Recreational use Legal – helium, nitrous oxide ("laughing gas") Illegal – various gaseous, vaporised or aerosolized recreational drugs Medical use Diag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poison
Poison is a chemical substance that has a detrimental effect to life. The term is used in a wide range of scientific fields and industries, where it is often specifically defined. It may also be applied colloquially or figuratively, with a broad sense. Whether something is considered a poison may change depending on the amount, the circumstances, and what living things are present. Poisoning could be accidental or deliberate, and if the cause can be identified there may be ways to neutralise the effects or minimise the symptoms. In biology, a poison is a chemical substance causing death, injury or harm to organisms or their parts. In medicine, poisons are a kind of toxin that are delivered passively, not actively. In industry the term may be negative, something to be removed to make a thing safe, or positive, an agent to limit unwanted pests. In ecological terms, poisons introduced into the environment can later cause unwanted effects elsewhere, or in other parts of the food ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venom
Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a stinger, in a process called envenomation. Venom is often distinguished from poison, which is a toxin that is passively delivered by being ingested, inhaled, or absorbed through the skin, and toxungen, which is actively transferred to the external surface of another animal via a physical delivery mechanism. Venom has evolved in terrestrial and marine environments and in a wide variety of animals: both predators and prey, and both vertebrates and invertebrates. Venoms kill through the action of at least four major classes of toxin, namely necrotoxins and cytotoxins, which kill cells; neurotoxins, which affect nervous systems; myotoxins, which damage muscles; and haemotoxins, which disrupt blood clotting. Venomous animals cause tens of thousa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semantics
Semantics (from grc, σημαντικός ''sēmantikós'', "significant") is the study of reference, meaning, or truth. The term can be used to refer to subfields of several distinct disciplines, including philosophy Philosophy (from , ) is the systematized study of general and fundamental questions, such as those about existence, reason, knowledge, values, mind, and language. Such questions are often posed as problems to be studied or resolved. Some ..., linguistics and computer science. History In English, the study of meaning in language has been known by many names that involve the Ancient Greek word (''sema'', "sign, mark, token"). In 1690, a Greek rendering of the term ''semiotics'', the interpretation of signs and symbols, finds an early allusion in John Locke's ''An Essay Concerning Human Understanding'': The third Branch may be called [''simeiotikí'', "semiotics"], or the Doctrine of Signs, the most usual whereof being words, it is aptly enough ter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenobiotic
A xenobiotic is a chemical substance found within an organism that is not naturally produced or expected to be present within the organism. It can also cover substances that are present in much higher concentrations than are usual. Natural compounds can also become xenobiotics if they are taken up by another organism, such as the uptake of natural human hormones by fish found downstream of sewage treatment plant outfalls, or the chemical defenses produced by some organisms as protection against predators. The term xenobiotics, however, is very often used in the context of pollutants such as dioxins and polychlorinated biphenyls and their effect on the biota, because xenobiotics are understood as substances foreign to an entire biological system, i.e. artificial substances, which did not exist in nature before their synthesis by humans. The term xenobiotic is derived from the Greek words ξένος (xenos) = foreigner, stranger and βίος (bios) = life, plus the Greek suffix ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxicant
A toxicant is any toxic substance, whether man-made or naturally occurring. By contrast, a toxin is a poison produced naturally by an organism (e.g. plant, animal, insect). The different types of toxicants can be found in the air, soil, water, or food. Occurrence Toxicants can be found in the air, soil, water, or food. Humans can be exposed to environmental toxicants. Fish can contain environmental toxicants. Cigarette smoke contains toxicants. E-cigarette aerosol also contains toxicants. The emissions of a heat-not-burn tobacco product contains toxicants. Most heavy metals are toxicants. Diesel exhaust contains toxicants. Pesticides, benzene, and asbestos-like fibers such as carbon nanotubes are toxicants. Possible developmental toxicants include phthalates, phenols, sunscreens, pesticides, halogenated flame retardants, perfluoroalkyl coatings, nanoparticles, e-cigarettes, and dietary polyphenols. Related terms By contrast, a toxin is a poison produced naturally by an or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Consumer Reports
Consumer Reports (CR), formerly Consumers Union (CU), is an American nonprofit consumer organization dedicated to independent product testing, investigative journalism, consumer-oriented research, public education, and consumer advocacy. Founded in 1936, CR was created to serve as a source of information that consumers could use to help assess the safety and performance of products. Since that time, CR has continued its testing and analysis of products and services, and attempted to advocate for the consumer in legislative and rule-making areas. Among the reforms in which CR played a role were the advent of seat belt laws, exposure of the dangers of cigarettes, and more recently, the enhancement of consumer finance protection and the increase of consumer access to quality health care. The organization has also expanded its reach to a suite of digital platforms. Consumer Reports Advocacy frequently supports left-wing environmental causes, including heightened regulations on auto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arsenic
Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but only the gray form, which has a metallic appearance, is important to industry. The primary use of arsenic is in alloys of lead (for example, in car batteries and ammunition). Arsenic is a common n-type dopant in semiconductor electronic devices. It is also a component of the III-V compound semiconductor gallium arsenide. Arsenic and its compounds, especially the trioxide, are used in the production of pesticides, treated wood products, herbicides, and insecticides. These applications are declining with the increasing recognition of the toxicity of arsenic and its compounds. A few species of bacteria are able to use arsenic compounds as respiratory metabolites. Trace quantities of arsenic are an essential dietary element in rats, ham ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Botulinum Toxin
Botulinum toxin, or botulinum neurotoxin (BoNT), is a neurotoxic protein produced by the bacterium ''Clostridium botulinum'' and related species. It prevents the release of the neurotransmitter acetylcholine from axon endings at the neuromuscular junction, thus causing flaccid paralysis. The toxin causes the disease botulism. The toxin is also used commercially for medical and cosmetic purposes. The seven main types of botulinum toxin are named types A to G (A, B, C1, C2, D, E, F and G). New types are occasionally found. Types A and B are capable of causing disease in humans, and are also used commercially and medically. Types C–G are less common; types E and F can cause disease in humans, while the other types cause disease in other animals. Botulinum toxins are among the most potent toxins known. Intoxication can occur naturally as a result of either wound or intestinal infection or by ingesting formed toxin in food. The estimated human lethal dose of type A toxin is 1.3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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