(from the article "pharmaceutical industry") ...Inhibition of carbonic anhydrase produces diuresis (urine formation). Subsequently, many sulfanilamide-like compounds were synthesized and screened for their ability to inhibit carbonic anhydrase. Acetazolamide, which was developed by scientists at Lederle Laboratories (now a part of Wyeth Pharmaceuticals, Inc.), became the first of a class of diuretics that serve as ...
the most important of the carboxylic acids. A dilute (approximately 5 percent by volume) solution of acetic acid produced by fermentation and oxidation of natural carbohydrates is called vinegar; a salt, ester, or acylal of acetic acid is called acetate. Industrially, acetic acid is used in the preparation of metal ... [9 Related Articles]
(from the article "ketene") ...combines with compounds containing an easily replaced hydrogen atom to yield derivatives of acetic acid. The only important industrial use of ketene itself is its reaction with acetic acid to form acetic anhydride.
(from the article "carboxylic acid") Pyruvic acid and acetoacetic acid are the simplest and most important of the alpha-keto and beta-keto acids, respectively.
(from the article "carboxylic acid") Acetoacetic acid (in the form of its ethyl ester, called ethyl acetoacetate) is the starting compound in a series of reactions (the acetoacetic ester synthesis) that is parallel to the malonic ester synthesis.
(from the article "metabolism") ...malonyl moiety (-OOCH2CO&singlehorzbond;). Simultaneously, the carbon dioxide fixed in step [62] is lost, leaving as a product a four-carbon moiety attached to ACP and called acetoacetyl-S-ACP [64].
(from the article "Some compounds produced by bacteria on an industrial scale") In 1864 the French physicist Louis Pasteur showed that it is Acetobacter bacteria that cause the conversion of alcohol to acetic acid. These bacteria work together symbiotically, producing enough acetic acid to prevent invasion by other organisms.
(from the article "bacteria") ...and Desulfuromonas reduce sulfate and elemental sulfur (S), respectively, yielding sulfide (S2−), and the bacterium Acetobacterium woodii and methanogenic archaea, such as Methanobacterium thermautotrophicum, reduce carbon dioxide to acetate and methane, respectively. The...
organic solvent of industrial and chemical significance, the simplest and most important of the aliphatic (fat-derived) ketones. Pure acetone is a colourless, somewhat aromatic, flammable, mobile liquid that boils at 56.2 °C (133 °F). [4 Related Articles]
(from the article "carboxylic acid") ...are organic cyanides. They are named after the corresponding carboxylic acids by changing -ic acid to -onitrile, or -nitrile, whichever preserves a single letter o. Thus, CH3CN is acetonitrile (from acetic acid), whereas C6H5CN is benzonitrile (from benzoic acid).
(from the article "acetaminophen") drug used in the treatment of mild pain, such as headache and pain in joints and muscles, and to reduce fever. It is formed in the body as a metabolite of acetanilid or phenacetin, which were once commonly used drugs, and is responsible for their analgesic effects. Acetaminophen relieves pain ...
an organic compound used as an ingredient in perfumes and as a chemical intermediate in the manufacture of pharmaceuticals, resins, flavouring agents, and a form of tear gas. It also has been used as a drug to induce sleep.
(from the article "bacteria") ...the carbon source. The most common pathways for synthesizing organic compounds from carbon dioxide are the reductive pentose phosphate (Calvin) cycle, the reductive tricarboxylic acid cycle, and the acetyl-CoA pathway (see photosynthesis: The process of photosynthesis: carbon fixation and reduction). The Calvin cycle, elucidated by American biochemist Melvin Calvin, is ...
(from the article "metabolism") ...and fatty acids (Figure 2), the molecule first undergoes a carboxylation, forming malonyl coenzyme A, before participating in fatty acid synthesis. The carboxylation reaction is catalyzed by acetyl CoA carboxylase, an enzyme whose prosthetic group is the vitamin biotin. The biotin-enzyme first undergoes a reaction that results in the attachment ...
(from the article "metabolism") ...as palmitic acid from acetyl coenzyme A and malonyl coenzyme A. The products of [63a] and [63b] are acetyl-S-ACP, malonyl-S-ACP, and coenzyme A. The enzymes catalyzing [63a] and [63b] are known as acetyl transacylase and malonyl transacylase, respectively. Acetyl-ACP and malonyl-ACP react in a reaction catalyzed by beta-ketoacyl-ACP synthetase so ...
(from the article "metabolism") ...ACP-SH is involved in all of the reactions leading to the synthesis of a fatty acid such as palmitic acid from acetyl coenzyme A and malonyl coenzyme A. The products of [63a] and [63b] are acetyl-S-ACP, malonyl-S-ACP, and coenzyme A. The enzymes catalyzing [63a] and [63b] are known as acetyl ...
(from the article "poison") Two types of conjugations, acetylations and methylation, do not enhance the excretion of the parent chemical. Acetylation and methylation decrease the water solubility of the parent chemical and mask the functional group of the parent chemical, preventing these functional groups from participating in conjugations that increase their excretion. Acetylation acts ...
(ACh), an ester of choline and acetic acid that is the transmitter substance at many neural, or nerve, synapses and at the motor end plate of vertebrate muscles (see end-plate potential). When a nerve impulse arrives at the nerve ending, ACh, which is stored there in vesicles, is released and ... [20 Related Articles]
(from the article "muscle") Acetylcholine receptors are ion channels that span the postsynaptic membrane, and they have extracellular, intramembranous, and cytoplasmic portions. They are located principally over the peaks of the postsynaptic folds, where they are present at high density. They consist of five subunits arranged around the central ion channel.function in neurotransmitter release
(from the article "acetylcholine") ...and a change in the nature of a generator potential results. The effects of successive nerve impulses accumulate if they arrive at a sufficiently high frequency. The ACh is destroyed by an enzyme, acetylcholinesterase, and thus is effective only briefly. Inhibitors of the enzyme, however, prolong the lifetime of ACh ...
the simplest and best-known member of the hydrocarbon series containing one or more pairs of carbon atoms linked by triple bonds, called the acetylenic series, or alkynes. It is a colourless, inflammable gas widely used as a fuel in oxyacetylene welding and cutting of metals and as raw material in ... [14 Related Articles]
(from the article "acetylene") The hydrogen atoms in acetylene can be replaced by metallic elements to form acetylides-e.g., acetylides of silver, copper, or sodium. The acetylides of silver, copper, mercury, and gold are detonated by heat, friction, or shock. In addition to its reactive hydrogen atom, the carbon-carbon triple bond can readily add halogens, ...
(from the article "red dog") In one version of red dog-also known as yablon, acey-deucey, and between the sheets-each player puts up an initial stake, and the banker deals two cards faceup. Unless the ranks of the cards are the same or consecutive, the bettors may increase their stakes by as much as the original ...
nomos (department) and historic region of Greece on the north coast of the Peloponnese, south of the Gulf of Corinth. In ancient times it was bounded on the west by Elis (modern Ilia), on the south by Mount Erymanthus and Arcadia, and on the east by Sicyon ... [4 Related Articles]
any of the ancient Greek people, identified in Homer, along with the Danaoi and the Argeioi, as the Greeks who besieged Troy. Their area as described by Homer-the mainland and western isles of Greece, Crete, Rhodes, and adjacent isles, except the Cyclades-is precisely that covered by the activities of the ... [1 Related Articles]
3rd-century-BC confederation of the towns of Achaea in ancient Greece. The 12 Achaean cities of the northern Peloponnese had organized a league by the 4th century BC to protect themselves against piratical raids from across the Corinthian Gulf, but this league fell apart after the death of Alexander the Great. ... [11 Related Articles]
eponymous ancestor of the Persian Achaemenid dynasty; he was the father of Teispes (Chishpish) and an ancestor of Cyrus II the Great and Darius I the Great. Although Achaemenes probably ruled only Parsumash, a vassal state of the kingdom of Media, many scholars believe that he led armies from Parsumash ... [1 Related Articles]
(559-330 BC), ancient Iranian dynasty whose kings founded and ruled the Achaemenian Empire. Achaemenes (Persian Hakhamanish), the Achaemenians' eponymous ancestor, is presumed to have lived early in the 7th century BC, but little is known of his life. From his son Teispes two lines of kings descended. The kings of ... [29 Related Articles]
(from the article "Antiochus III") The son of Seleucus II, Antiochus succeeded his brother Seleucus III as king. He retained from the previous administration Hermias as chief minister, Achaeus as governor of Asia Minor, and Molon and his brother Alexander as governors of the eastern provinces, Media and Persis. In the following year, when Molon ...
South American Indian people of Venezuela and eastern Colombia. They speak a language of the Maipurean Arawakan group. Traditionally, the Achagua had typical tropical-forest economies, living in large villages and growing bitter cassava and other crops. The Achagua were warlike; they were one of the few native South American people ... [1 Related Articles]
(from the article "esophagus") Disorders of the esophagus include ulceration and bleeding; heartburn, caused by gastric juices in the esophagus; achalasia, an inability to swallow or to pass food from the esophagus to the stomach, caused by destruction of the nerve endings in the walls of the esophagus; scleroderma, a collagen disease; and spasms ...
(from the article "Malpighiales") Achariaceae contains 30 genera and 145 species of shrubs to trees, or rarely climbing herbs, which are scattered throughout the tropics. The Indo-Malesian Hydnocarpus (40 species) is the largest genus in the family. Ryparosa (18 species) is Malesian, and Lindackeria (14 species) grows in the Americas and Africa. Most species ...
(from the article "gastropod") In some places, introductions of Achatina and Helix have resulted in damage to crops and gardens by these rapidly multiplying snails. On the other hand, habitat degradation, the introduction of predatory rats and land snails, and shell collecting by humans have caused the extinction of about 50 percent of all ...
(from the article "gastropod") ...and forest-litter snails (Stenopylis, Punctum) are less than one millimetre (0.04 inch) in diameter. At the other extreme, the largest land snail, the African Achatina achatina, forms a shell that is almost 20 centimetres (eight inches) long. The largest freshwater snails, Pomacea from South ...
(from the article "gastropod") ...altered in sluglike forms; about 18,000 species.A group of 4 superfamilies.Besides the giant African snail, 4 families, including many species spread by commerce throughout the world.
(from the article "gastropod") ...into mantle cavity (part of the viscera) near anterior margin of lung after ureter passes forward from anterior kidney margin; about 6,000 species.Minute to medium-sized Pacific land snails with multicuspid radular denticles; many Hawaiian species highly coloured and...
nomadic South American Indian people living in eastern Paraguay. The Ache speak a Tupian dialect of the Tupi-Guaranian language family. They live in the densely forested, hilly region between the Paraguay and Parana rivers. In pre-Spanish times, the Ache lived a more settled, agricultural life in a less harsh environment, ... [3 Related Articles]
Ghanaian army officer, who, after leading a military revolt that overthrew the government of Kofi Busia, became Ghana's chief of state in 1972. In July 1978 he was forced to resign, and the following June he and his successor, Lieut. Gen. F.W.K. Akuffo, were executed after a coup led by ... [3 Related Articles]
prominent Igbo (Ibo) novelist acclaimed for his unsentimental depictions of the social and psychological disorientation accompanying the imposition of Western customs and values upon traditional African society. His particular concern was with emergent Africa at its moments of crisis; his novels range in subject matter from the first contact of ... [1 Related Articles]
(from the article "Western architecture") The ecclesiastical architecture of the East is more varied, partly as a result of differences in the liturgies. The monastery of St. John the Baptist of Studium in Constantinople (463) and the church of the Acheiropoietos at Thessalonica (470) were basilicas with tribunes and narthexes, which, in their proportions, approached ...
one of the longest rivers in Greece, rising in the Pindus Mountains of central Epirus (Ipiros) and dividing Aetolia from Acarnania. It debouches into the Ionian Sea after a course of 140 mi (220 km), mostly through gorges. Well above Agrinion two hydroelectric dams were built to harness the waters ...
(from the article "Bavarian Alps") ...to the north its gentle slopes allow the grazing of cattle. The mountains hold lignite mines and petroleum deposits and are crossed at Scharnitz Pass (3,133 feet [955 m]) by road and railway and at Achen Pass (3,087 feet [941 m]) by road. Tourism and winter sports are the region's ...
landscape painter, a pioneer of the German realist school. He studied at the Dusseldorf academy under Johann Wilhelm Schirmer, but emancipated himself from the contemporary school of landscapists that delighted in the representation of romantic scenery. He was the first artist of the Dusseldorf school to paint nature for its ...
landscape painter of the Dusseldorf school who is distinguished for his colourful renderings of the Bay of Naples, of Rome, and of Venice. He broke away from the traditional classicist interpretation of these scenes and revelled in strong and glowing colour effects. His more famous brother, Andreas, influenced his work.
dry, one-seeded fruit lacking special seams that split to release the seed. The seed coat is attached to the thin, dry ovary wall (husk) by a short stalk, so that the seed is easily freed from the husk, as in buckwheat. The fruits of many plants in the buttercup family ... [5 Related Articles]
former city, central Heilongjiang sheng (province), far northeastern China. In 2006 it was incorporated into the city of Harbin, and it became a southeastern district of that city.
river in Thesprotia in Epirus, Greece, that was thought in ancient times to go to Hades because it flowed through dark gorges and went underground in several places; an oracle of the dead was located on its bank. In Greek mythology it is a river in Hades, and the name ...
(from the article "canon law") ...code. About 800 the Hadriana and the Hispana were developed into a systematic whole, the Dacheriana (canonical collection named for its 17th-century publisher, French scholar Jean-Luc d'Achery)-the principal source of the collections before 850-which was of influence until the Gregorian reform in the 11th century.
