BIOCHEMISTRY © 2016 Paul Billiet ODWS

Period table of elements © 2016 Paul Billiet ODWS

Period table of elements © 2016 Paul Billiet ODWS

C, H, O, N, P and S Elements of biological importance H, O, C, are the most common N, S, P are also important as well as the metals Na, Ca, and Fe H, O, C, N, S and P form covalent bonds (single, double or triple e.g. –C-C-, -C=O –CN) H, O, C, N, S and P are light H, O, C, N, S and P very reactive H, O, C, N, S and P produce diverse compounds which are reduced (readily oxidised). © 2016 Paul Billiet ODWS

CARBON Tetravalent  4 different bonds  variety  isomerism Forms long chains (polymers)  macromolecules and ring structures Tetrahedral structure  3-D variation  optical isomerism. © 2016 Paul Billiet ODWS

Organic compounds Compounds containing carbon found in living organisms Not including carbonates, hydrogen carbonates, CO2 or CO Often based upon a skeleton of carbon An infinite variety possible Evolution has chosen a few for use in living organisms There are just four principal groups: sugars, fatty acids, amino acids and nucleotides. © 2016 Paul Billiet ODWS

The vitalisitic theory Vitalism: living organisms are fundamentally different from non-living systems Living things contain some non-physical element (spirit, soul) Living organism are governed by different rules than non-living systems. © 2016 Paul Billiet ODWS

Urea and the vitalisitic theory Vitalism maintained that organic materials could not be synthesised from inorganic components Wöhler (1828) synthesized UREA from ammonium chloride + silver cyanate. Friedrich Wöhler © 2016 Paul Billiet ODWS