Hy-Kr

Hydrolysis - Chemistry Encyclopedia

Hydrolysis literally means reaction with water. It is a chemical process in which a molecule is cleaved into two parts by the addition of a molecule of water.

Ibuprofen - Chemistry Encyclopedia

Ibuprofen is a well-known drug that possesses analgesic (pain-relieving) and antipyretic (fever-reducing) properties. It is particularly known for its use in pain relief from arthritis.

Indium - Chemistry Encyclopedia

Indium is a soft, silver-white metal. It was first isolated in 1863 by German chemists Ferdinand Reich and Hieronymus Theodor Richter.

Inorganic Industrial Chemistry - Chemistry Encyclopedia

Industrial inorganic chemistry includes subdivisions of the chemical industry that manufacture inorganic products on a large scale such as the heavy inorganics (chlor-alkalis, sulfuric acid, sulfates) and fertilizers (potassium, nitrogen, and phosphorus products) as well as segments of fine chemicals that are used to produce high purity inorganics on a much smaller scale. Among these are reagents and raw materials used in high-tech industries, pharmaceuticals or electronics, for example, as well as in the preparation of inorganic specialties such as catalysts, pigments, and propellants.

Organic Industrial Chemistry - Chemistry Encyclopedia

Industrial organic chemicals are those 100 or so organic compounds produced in the United States in quantities ranging from millions of pounds to billions of pounds per year. Most of them are derived from petroleum (oil) or natural gas.

Inhibitors - Chemistry Encyclopedia

An inhibitor is any agent that interferes with the activity of an enzyme. Inhibitors may affect the binding of enzyme to substrate, or catalysis (via modification of the enzyme's active site), or both.

Inorganic Chemistry - Chemistry Encyclopedia

The scope and boundaries of inorganic chemistry were shaped by the earlier field of organic chemistry in the mid-eighteenth and later centuries. Back in these earlier days of chemistry, all chemicals not classified as organic, in other words all chemicals, including minerals and alloys, that do not have an origin in living organisms, were placed in a very large category of "inorganic" substances.

Insecticides - Chemistry Encyclopedia

Insecticides are natural or synthetic chemicals used to manage insects pests; they are important for disease control and providing food and fiber for a growing world population. Insect control with chemicals began about 2,000 years ago with the use of natural products, whereas the age of synthetic insecticides began with the introduction of dichlorodiphenyl trichloroethane (DDT) in the 1940s.

Insulin - Chemistry Encyclopedia

Insulin is a small peptide (protein) consisting of fifty-one amino acids synthesized and stored within the pancreas, an organ situated behind the stomach. The protein itself consists of two chains, denoted A and B, linked by disulfide (sulfur-sulfur) bridges between cysteine residues (see Figure 1).

Interferon - Chemistry Encyclopedia

Interferon, a small protein containing fewer than two hundred amino acids, is an interesting example of a biologically active polypeptide. There are three classes of interferon, labeled by the first three letters of the Greek alphabet.

International System of Units - Chemistry Encyclopedia

The International System of Units (SI), which began as the decimal metric system during the French Revolution, deals with the definitions, terminology, proper usage, and modifications of scientific units. The metric system was established officially in France on June 22, 1799, and consisted of two standard measures: the meter for length and the kilogram for mass.

Iodine - Chemistry Encyclopedia

Iodine is the heaviest of the halogen family of elements, excluding the radioactive element astatine. It was discovered in 1811 by French chemist Bernard Courtois, who isolated the element from seaweed.

Ion Channels - Chemistry Encyclopedia

Ion channels play a fundamental role in the way cells communicate. They generate the electrical signals that make hearts beat and muscles contract, and allow brains to receive and process information.

Iridium - Chemistry Encyclopedia

Iridium was discovered by English chemist Smithson Tenant. It was named after the Greek goddess Iris (a goddess related to the rainbow) because of the variety of color in its compounds.

Iron - Chemistry Encyclopedia

Iron, believed to have been introduced on Earth by meteors, was found in Egyptian tombs dating from 3500 B.C.E. The Hittites (in the area known today as Turkey) smelted iron from ore around 1500 B.C.E.

Irradiated Foods - Chemistry Encyclopedia

Irradiation is the process of exposing a material to ionizing radiation whose source is photons (γ-rays, x rays), or high energy electrons. Commonly, γ-rays are produced by radioactive isotopes such as cobalt-60 and cesium-137.

Isomerism - Chemistry Encyclopedia

The term "isomer" (iso from the Greek meaning same and meros meaning part) describes the relationship between molecular arrangements that, although differing in chemical or physical properties, have a level of commonality (have the "same parts"). There are two distinct levels of commonality used to describe molecular structure: one that excludes and one that includes three-dimensional considerations.

Kinase - Chemistry Encyclopedia

Kinases are enzymes that transfer a phosphate group from adenosine triphosphate (ATP), or other trinucleotide, to a number of biological substrates, such as sugars or proteins. They are part of a larger family of enzymes known as group transferases, but are limited to phosphate transfers.

Kinetics - Chemistry Encyclopedia

Chemical kinetics is the study of the rates of chemical reactions. Such reaction rates range from the almost instantaneous, as in an explosion, to the almost unnoticeably slow, as in corrosion.

Krebs Cycle - Chemistry Encyclopedia

The Krebs cycle is a series of enzymatic reactions that catalyzes the aerobic metabolism of fuel molecules to carbon dioxide and water, thereby generating energy for the production of adenosine triphosphate (ATP) molecules. The Krebs cycle is so named because much of its elucidation was the work of the British biochemist Hans Krebs.