Macromolecules are extremely large molecules with a relatively large mass, the properties of which remain unaffected by the removal of individual atoms or groups of atoms. DNA and proteins are typical naturally occurring macromolecules, whilst all polymers are typical synthetic macromolecules.
Melanin is a pigment responsible in humans for skin colour, among othe things, and which protects the skin against harmful UV radiation.
also known as black-mole cancer - A melanoma is a malignant tumour appearing as an asymmetrically growing, discoloured change in the skin.
Chemical symbol Hg - Mercury is a shiny-silver, liquid heavy metal with an especially high cohesion, which therefore tends to form droplets. Mercury has the property of expanding considerably when heated. In the temperature range between 0 °C and 100 °C this expansion is directly proportional to the temperature.
Mercury actually evaporates even at room temperatures, and is highly toxic in this gaseous form! For this reason, mercury-vapour lamps (fluorescent tubes, energy-saving lamps, UV tubes) DO NOT BELONG IN THE HOUSEHOLD WASTE!
The term metabolism describes the uptake, transport and chemical transformation of matter in an organism, as well as the discharge of metabolic end products into the environment.
also micron - The unit µm. Conversion: 1 µm = 0.001 mm.
also microbe - Microorganisms are organic structures so small that they can generally only be seen with the aid of a microscope. Such structures are usually single-celled, although they are occasionally multi-celled.
The unit µW. Conversion: 1 µW = 0.001 mW = 0.000001 W.
The term molecule describes a particle formed from two or more atoms which is at least temporarily stable. Molecules can be formed from atoms of the same element, e.g. oxygen (O2), ozone (O3) and nitrogen (N2), or from atoms of different elements, e.g. water (H2O).
describes radiation of a precisely defined wavelength, as e.g. emitted by a laser.
Monomers are reactive molecules which in terms of a basic unit may congregate into chains or networks.
The word mould is not clearly defined, but tends to be a colloquial umbrella term for a whole range of microorganisms that can colonise the surface of and spoil food and feedstuffs as well as other products of human activity (Kreisel 1988). A large proportion of this group belongs to the sac fungi (ascomycetes) and zygote fungi (zygomycetes). Common to all organisms termed moulds is the three-stage life cycle of mycelium, conidiophore and spore.
[Abbr. of methicillin-resistant Staphylococcus aureus] In the narrower sense, MRSA is taken to mean Staphylococcus aureus strains which are resistant to all beta lactam antibiotics (e.g.penicillin) available up to the present on the market.
also peptidoglycan - Murein is a three-dimensional biopolymer with a net-like structure functioning as a supporting skeleton of the cell wall in the case of bacteria. The macromolecule consists of amino acids and sugar molecules.
We speak of a mutation when the highly stable genetic algorithm of the hereditary material (DNA) of an organism undergoes a relatively permanent, stable change. Unlike with a modification, a mutation is permanently replicated.