CHEMISTRY GLOSSARY

infrared radiation    →   infracrveno zračenje

Infrared radiation is an electromagnetic radiation within the area from 1.0 μm to 300 μm, and is responsible for the transmission of radiant heat.

ion exchanger    →   ionski izmjenjivač

Ion-exchanger is a solid or liquid material containing ions that are exchangeable with other ions with a like charge that are present in a solution in which the material is insoluble. Ion-exchange resins consist of various copolymers having a cross-linked three-dimensional structure to which ionic groups have been attached.

ion selective electrode    →   ion selektivne elektrode

Ion selective electrode (ISE) is an electrode or electrode assembly with a potential that is dependent on the concentration of an ionic species in the test solution and is used for electroanalysis. Ion-selective electrodes are often membrane type electrodes.

ionic bond    →   ionska veza

Ionic bond is a strong force of attraction holding atoms together in a molecule or crystal. Typically chemical bonds have energies of about 100 kJ mol^-1. Ionic bond is a bond at which one of the participants, during the procedure of bonding, gives away its unpaired electrons to another atom so that both can achieve electron arrangement of the closest noble gas. In order to form an ionic bond one of the atoms must cross to the positively charged ion by losing certain number of electrons and the other atom must receive those electrons and cross to the negatively charged ion.

ionic radius    →   ionski radijus

Ionic radius is the radius of anions and cations in crystalline ionic compounds, as determined by consistently partitioning the center-to-center distance of ions in those compounds. In general, negative ions have larger ionic radii than positive ions.

iron    →   željezo

Iron has been known since ancient times. The origin of the name comes from the Latin word ferrum meaning iron. It is malleable, ductile, silvery-white metal. Exposed surfaces form red-brown oxides. Forms very strong alloys (steel). Ferromagnetic. Metal dust flammable. Fourth most abundant element in the earth’s crust. Iron is obtained from iron ores. Pure metal produced in blast furnaces by layering limestone, coke and iron ore and forcing hot gasses into the bottom. This heats the coke red hot and the iron is reduced from its oxides and liquefied where it flows to the bottom. Iron is the most common metal in human society. More than 90 % of all metal refined in the world is iron. Used in steel and other alloys. It is the chief constituent of hemoglobin which carries oxygen in blood vessels. Its oxides are used in magnetic tapes and disks.

isoelectric point    →   izoelektrična točka

Isoelectric point (pI or IEP) is the pH of a solution or dispersion at which the net charge on the molecules or colloidal particles is zero. In electrophoresis there is no motion of the particles in an electric field at the isoelectric point. The net charge (the algebraic sum of all the charged groups present) of any amino acid, peptide or protein, will depend upon the pH of the surrounding aqueous environment. For example, alanine can have a charge of +1, 0, or -1, depending on the pH of the solution in which it is dissolved.

isoleucine    →   izoleucin

Isoleucine is hydrophobic amino acids with aliphatic side chain. It is one of the three amino acids having branched hydrocarbon side chains. The side chains of these amino acids are not reactive but, these residues are critically important for ligand binding to proteins, and play central roles in protein stability. Isoleucine is an essential amino acid, which means that humans cannot synthesize it, so it must be ingested.

• Abbreviations: Ile, I
• IUPAC name: 2-amino-3-methylpentanoic acid
• Molecular formula: C₆H₁₃NO₂
• Molecular weight: 131.12 g/mol

ketal    →   ketal

Ketals are organic compounds formed by addition of an alcohol to a ketone. If one molecule of ketone (RR’CO) reacts with one molecule of alcohol (R"OH) then a hemiketal is formed. The rings of ketose sugars are hemiketals. Further reaction produces a full ketal (RR’C(OR")₂). This term, once abandoned, has been reinstated as a subclass of acetals.

ketone    →   keton

Ketones are compounds in which a carbonyl group is bonded to two carbon atoms: R₁R₂C=O (neither R may be H). They are derived by oxidation of secondary alcohols. The simplest member of the series is acetone, (CH₃)₂CO.