CHEMISTRY GLOSSARY

precipitate    →   precipitat

Precipitate or the deposit is an insoluble solid formed by reactions in a solution. For example, when a solution of silver nitrate is added to a solution of sodium chloride, insoluble silver chloride precipitates.

precursor    →   prekursor

Precursor means any chemical reactant which takes part at any stage in the production by whatever method of a toxic chemical. This includes any key component of a binary or multicomponent chemical system. A zymogen (or proenzyme) is an inactive enzyme precursor.

preservative    →   konzervans

Preservatives are substances that will prevent the development of wood-destroying fungi, borers of various kinds, and other harmful insects that deteriorate wood.

pressure    →   tlak

Pressure (p) is the force acting normally on unit area of a surface. It is measured in pascals in Si units (Pa)

primary alcohol    →   primarni alkohol

Primary alcohols are alcohols where the hydroxyl group is attached to a primary carbon atom. Thus, it has the general structure, RCH₂OH, where R is a hydrogen atom or an alkyl group.

primary amine    →   primarni amin

Primary amine is an amine on which there is only one alkyl group bonded, it is a weak base, and has a fish odour.

primary structure of proteins    →   primarna struktura proteina

Primary structure of proteins is a sequence of defined amino acids in some protein.

product    →   produkt

Products are substances developed by chemical reactions from reactants.

promoter    →   promotor

Promoter is any component added to a catalyst to increase activity or selectivity. Examples are tin added to platinum reforming catalysts to improve selectivity to coke formation and chloride added to isomerization catalysts to increase activity.

living planet index    →   indeks života na planetu

The Living Planet Index (LPI) reflects changes in the health of the planet's ecosystems by tracking trends in nearly 8000 populations of vertebrate species. The LPI first calculates the annual rate of change for each species population in the dataset, then calculates the average change across all populations for each year from 1970, when data collection began, to 2007, the latest date for which data is available.

The Global LPI shows a decline of around 30 % from 1970 to 2007, based on 7953 populations of 2544 species of birds, mammals, amphibians, reptiles and fish.