CHEMISTRY GLOSSARY

aspartic acid    →   asparaginska kiselina

Aspartic acid is an electrically charged amino acids with acidic side chains. As a group the charged amino acids are relatively abundant and are generally located on the surface of the protein. Aspartic acid and glutamic acid play important roles as general acids in enzyme active centers, as well as in maintaining the solubility and ionic character of proteins. Aspartic acid (sometimes referred to as asparate depending on pH) is non-essential in mammals, being produced from oxaloacetate by transamination.

• Abbreviations: Asp, D
• IUPAC name: 2-aminobutanedioic acid
• Molecular formula: C₄H₇NO₄
• Molecular weight: 133.10 g/mol

glutamic acid    →   glutaminska kiselina

Glutamic acid is an electrically charged amino acids. It is one of the two amino acids that contain a carboxylic acid group in its side chains. These acids play important roles as general acids in enzyme active centers, as well as in maintaining the solubility and ionic character of proteins. Glutamic acid is commonly referred to as glutamate, because its carboxylic acid side chain will be deprotonated and thus negatively charged in its anionic form at physiological pH. Glutamic acid is referred to as a non-essential amino acid because a healthy human can synthesize all the glutamic acid needed for normal body function from other amino acids.

• Abbreviations: Glu, E
• IUPAC name: 2-aminopentanedioic acid
• Molecular formula: C₅H₉NO₄
• Molecular weight: 147.13 g/mol

acid    →   kiselina

Acid is a type of compound that contains hydrogen and dissociates in water to produce positive hydrogen ions. The reaction for an acid HA is commonly written:

In fact, the hydrogen ion (the proton) is solvated, and the complete reaction is:

This definition of acids comes from the Arrhenius theory. Such acids tend to be corrosive substances with a sharp taste, which turn litmus red and produce colour changes with other indicators. They are referred to as protonic acids and are classified into strong acids, which are almost completely dissociated in water, (e.g. sulphuric acid and hydrochloric acid), and weak acids, which are only partially dissociated (e.g. acetic acid and hydrogen sulphide). The strength of an acid depends on the extent to which it dissociates, and is measured by its dissociation constant.

In the Lowry-Brønsted theory of acids and bases (1923), the definition was extended to one in which an acid is a proton donor (a Brønsted acid), and a base is a proton acceptor (a Brønsted base). An important feature of the Lowry-Brønsted concept is that when an acid gives up a proton, a conjugate base is formed that is capable of accepting a proton.

Similarly, every base produces its conjugate acid as a result of accepting a proton.

For example, acetate ion is the conjugate base of acetic acid, and ammonium ion is the conjugate acid of ammonia.

As the acid of a conjugate acid/base pair becomes weaker, its conjugate base becomes stronger and vice versa.

A further extension of the idea of acids and bases was made in the Lewis theory. In this, a G. N. Lewis acid is a compound or atom that can accept a pair of electrons and a Lewis base is one that can donate an electron pair. This definition encompasses "traditional" acid-base reactions, but it also includes reactions that do not involve ions, e.g.

in which NH₃ is the base (donor) and BCl₃ the acid (acceptor).

acrylic acid    →   akrilna kiselina

Acrylic acid (propenoic acid) is a colourless liquid, smelling like acetic acid. It can be formed by acrolein oxidation. It readily polymerizes and is used in the manufacture of acrylic resins, transparent plastic materials (organic glass).

battery acid    →   baterijska kiselina

Battery acid is a solution of approximately 6 mol L^-1 sulphuric acid used in the lead storage battery

Bronsted acid    →   Bronstedova kiselina

Brøsted acid is a material that gives up hydrogen ions in a chemical reaction.

Bronsted-Lowry’s acid-base theory    →   Bronsted-Lowryeva teorija kiselina i lužina

Brønsted-Lowry’s acid-base theory: Acid is a substance which gives a proton (protondonor) and base is a substance which accepts a proton (protonacceptor).

conjugated acid    →   konjugirana kiselina

Conjugated acid is a particle that develops after a base receives a proton.

glacial acetic acid    →   ledena octena kiselina

Glacial acetic acid (CH₃COOH) is the pure compound, as distinguished from the usual water solutions known as acetic acid. It is a colorless liquid or crystalline substance (melting point 16.6 °C) with a pungent, vinegar odor.

Lewis acid    →   Lewisova kiselina

Lewis acid is an agent capable of accepting a pair of electrons to form a coordinate bond.