CHEMISTRY GLOSSARY
close-packed structure → gusta slagalina
Close packing is the packing of spheres so as to occupy the minimum amount of space. The name close packed refers to the packing efficiency of 74.05 %. There are two types of close packing: hexagonal and cubic. One layer, with atoms centered on sites labeled a. Two layers, with the atoms of the second layer centered on sites labeled b. The third layer can be placed on the sites labeled c (giving cubic close-packing) or over those marked a (giving hexagonal close-packing).
cobalt → kobalt
Cobalt was discovered by Georg Brandt (Germany) in 1735. The origin of the name comes from the German word kobald meaning goblin or evil spirit. It is hard, ductile, lustrous bluish-grey metal. Surfaces stable in air. Reacts over time with dilute acids. It has remarkable magnetic properties. Cobalt occurs in compounds with arsenic and sulfur as in cobaltine (CoAsS) and linneite (Co3S4). Pure cobalt is obtained as a by-product of refining nickel, copper and iron. Used in many hard alloys; for magnets, ceramics and special glasses. Radioactive cobalt-60 is used in cancer therapy.
coenzyme a → koenzim a
Coenzyme A (CoA) is an essential metabolic cofactor synthesized from cysteine, pantothenate (vitamin B5), and ATP. CoA plays important roles in many metabolic pathways, including the tricarboxylic acid (TCA) cycle, and the synthesis and oxidation of fatty acids. One of the main functions of CoA is the carrying and transfer of acyl groups. Acylated derivatives (acetyl-CoA) are critical intermediates in many metabolic reactions.
heat of fusion → toplina taljenja
Heat of fusion or enthalpy of fusion is the heat required to convert a substance from the solid to the liquid state with no temperature change (also called latent heat of fusion or melting).
heat of vaporisation → toplina isparavanja
Heat of vaporisation or enthalpy of vaporisation is the heat required to convert a substance from the liquid to the gaseous state with no temperature change (also called latent heat of vaporization).
coenzyme q → koenzim q
Coenzyme Q (CoQ) or ubiquinone is any of a group of related quinone-derived compounds that serve as electron carriers in the electron transport chain reactions of cellular respiration. There are some differences in the length of the isoprene unit (in bracket on left) side chain in various species. All the natural forms of CoQ are insoluble in water, but soluble in membrane lipids.
colloid → koloid
Colloids are systems in which there are two or more phases, with one (the dispersed phase) distributed in the other (the continuous phase). Moreover, at least one of the phases has small dimensions, in the range between 1 nm and 1 μm (10-9 m – 10-6 m). Dimension, rather than the nature of the material, is characteristic. In this size range, the surface area of the particle is large with respect to its volume so that unusual phenomena occur, e.g., the particles do not settle out of the suspension by gravity and are small enough to pass through filter membranes. Macromolecules (proteins and other high polymers) are at the lower limit of this range; the upper limit is usually taken to be the point at which the particles can be resolved in an optical microscope.
Colloidal particles may be gaseous, liquid, or solid, and occur in various types of suspensions:
Sols - dispersions of small solid particles in a liquid.
Emulsions - colloidal systems in which the dispersed and continuous phases are both liquids.
Gels - colloids in which both dispersed and continuous phases have a three-dimensional network throughout the material.
Aerosols - colloidal dispersions of liquid or solid particles in a gas.
Foams - dispersions of gases in liquids or solids.
Citing this page:
Generalic, Eni. "Ledište." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
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