CHEMISTRY GLOSSARY

sucrose    →   saharoza

Sucrose (saccharose), or ordinary table sugar, is a disaccharide in which α-D-glucopyranose and β-D-fructofuranose are joined at their anomeric carbons by a glycosidic bond. There are no hemiacetals remaining in the sucrose and therefore sucrose is not a reducing sugar and does not exhibit mutarotation. Sugar is a white crystalline sweet compound found in many plants and extracted from sugar cane and sugar beet. It is used as a sweetening agent in food and drinks. If heated to 200 °C, sucrose becomes caramel. When sucrose is hydrolyzed it forms an equimolar mixture of glucose and fructose. This mixture of monosaccharides is called invert sugar. Honeybees have enzymes called invertases that catalyze the hydrolysis of sucrose. Honey, in fact, is primarily a mixture of glucose, fructose, and sucrose.

Chitin    →   Hitin

Chitin is a nitrogen-containing linear polysaccharide of ß(1->4) linked units of N-acetyl-ß-d-glucosamine. The structure of chitin is similar to cellulose except for the replacement hydroxyl group (-OH) at the carbon 2 with an acetyl amine group (–NH–CO–CH3). Chitin is the main component of the exoskeleton, or outer covering of insects, crustaceans, and arachnids. It is also found in the cell walls of certain fungi and algae. After cellulose, chitin is the second most abundant biopolymer in nature. It is insoluble in water, organic solvents, weak acids and lyes.

acceptor    →   akceptor

Acceptor is a compound, molecule or ion, to which electrons are donated in the formation of a coordinate bond

activator    →   aktivator

Activator is a substance that increases the activity of a catalyst; for example, a substance that - by binding to an allosteric site on an enzyme - enables the active site of the enzyme to bind to the substrate.

addition reactions    →   reakcije adicije

Addition reactions are normally occur with unsaturated compounds and involve the addition of one molecule (called the reactant) across the unsaturated bond (i.e. the double bond or the triple bond) of another molecule (called the substrate) to give a single product, formed by the combination of both reacting molecules.

For example, bromine adds across the double bond of ethene in an addition reaction to form dibromoethane.

agarose    →   agaroza

Agarose is a polysaccharide obtained from agar that is used for a variety of life science applications especially in gel electrophoresis. The structure of agarose consists of alternating (1→3)-linked β-D-galactopyranose and (1→4)-linked 3,6-anhydro-α-L-galactopyranose.

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.

aldehydes    →   aldehidi

Aldehydes are a broad class of organic compounds having the generic formula RCHO, and characterized by an unsaturated carbonyl group (C=O). They are formed from alcohols by either dehydrogenation or oxidation. Their chemical derivation is indicated by the name al(cohol) + dehyd(rogenation). An example of these distinct aromatic compounds is formaldehyde.

amide    →   amid

Amide is an organic compound that contains a carbonyl group bound to nitrogen. The simplest amides are formamide (HCONH₂) and acetamide (CH₃CONH₂).

amino acids    →   aminokiseline

Amino acids are compounds containing both a carboxylic acid group (-COOH) and an amino group (-NH₂ ). The most important are the α-amino acids, in which the -NH₂ group in attached to the C atom adjacent to the -COOH group. In the β-amino acids, there is an intervening carbon atom.