CHEMISTRY GLOSSARY

agar    →   agar

Agar, also called agar-agar, is an extract of certain species of red algae (of the Gelidium and Gracilaria genera) that is used as a gelling agent in microbiological culture media, foodstuffs, medicine, and cosmetic. The predominant component of agar is agarose, a polysaccharide made up of subunits of the sugar galactose.

ageing    →   starenje

Ageing is the physical and/or chemical change of a material with respect to time, under defined environmental conditions, leading to improvement or deterioration of properties.

alabaster    →   alabaster

Alabaster is a monoclinic mineral form of hydrated calcium sulphate. It is a pure fine-grained translucent form of gypsum. CaSO₄·2H₂O.

aliquot    →   alikvot

Aliquot is a known volume of liquid that represents a part of some larger volume. It is usually taken with a pipette from a measured flask.

alkalinity    →   alkalitet

Alkalinity is a measure of a material’s ability to neutralize acids. It is usually determined using titration.

alkaloid    →   alkaloid

Alkaloids are basic nitrogen organic compounds (mostly heterocyclic) derived from plants and having diverse pharmacological properties. Alkaloids include morphine, cocaine, atropine, quinine, and caffeine, most of which are used in medicine as analgesics or anaesthetics. Some alkaloids are poisonous, e.g. strychnine and coniine, and colchicine inhibit cell division.

air    →   zrak

Air that we breathe is a mixture of gases. The composition of dry-air at sea level is shown below:

air stripping    →   zračni striping

Air stripping is a process for the removal of volatile organic contaminants from groundwater. The groundwater flows downward inside a tower filled with materials (the packing) over a large surface area. Air is introduced at the bottom of the tower and is forced upward past the falling water. The volatiles evaporate from the water and are collected in air filters or released to the atmosphere.

alanine    →   alanin

Alanine is hydrophobic amino acids with aliphatic side chain. It is the second simplest amino acid, but used the most in proteins. The nonpolar hydrophobic amino acids tend to cluster together within proteins, stabilizing protein structure by means of hydrophobic interactions. Alanine is a nonessential amino acid, meaning it can be manufactured by the human body, and does not need to be obtained directly through the diet.

• Abbreviations: Ala, A
• IUPAC name: 2-aminopropanoic acid
• Molecular formula: C₃H₇NO₂
• Molecular weight: 89.09 g/mol

alcohol    →   alkohol

Alcohols are compounds in which a hydroxy group, -OH, is attached to a saturated carbon atom. Smaller members are water soluble, inflammable and are useful as organic solvents and fuels.