Molecular Biology PDF - Topic 2.1

Topic 2.1: moleculAR biology Metabolism Metabolism describes the totality of chemical processes that occur within a living organism in order to maintain life It is the web of all enzyme–catalysed reactions that occur within a particular cell or organism Molecular biology explains these biologica...

Topic 2.1: moleculAR biology Metabolism Metabolism describes the totality of chemical processes that occur within a living organism in order to maintain life It is the web of all enzyme–catalysed reactions that occur within a particular cell or organism Molecular biology explains these biological processes in terms of the chemical substances (molecules) involved Organic Compounds Biomacromolecules Organic compounds are molecules that contain carbon There are four main groups of organic compounds in cells: and are found in living things Carbohydrates, lipids, proteins and nucleic acids Exceptions include carbonates and oxides of carbon Carbohydrates, proteins and nucleic acids are all made up of Carbon atoms form the basis of organic life due to their recurring subunits (monomers) capacity to form four covalent bonds This allows a diversity of stable compounds to exist CLASS MONOMER POLYMER Carbohydrate Monosaccharide Polysaccharide Protein Amino acid Polypeptide 4 valence 4 empty Nucleic Acid Nucleotide DNA / RNA electrons slots Lipids are not composed of repeating monomers, but may contain smaller subunits (e.g. triglycerides) CARBON ATOM CLASS SUBUNITS CONFIGURATION 6 ELECTRONS 1s2 2s2 2px1 2py1 2pz0 Triglyceride Glycerol + Fatty Acid (×3) Types of Reactions Anabolism Catabolism The synthesis of complex molecules from simpler ones The breakdown of complex molecules into simpler ones Involves condensation reactions (water is produced) Involves hydrolysis reactions (water is consumed) An example of an anabolic reaction is photosynthesis An example of a catabolic reaction is cellular respiration ANABOLISM via CONDENSATION CATABOLISM via HYDROLYSIS Small molecules join into Large︎ molecule Large molecule breaks to Small︎ molecules Water produced ✓ H2O H2O H2O H2O H2O H2O ✗ Water consumed Vitalism Theory of Vitalism Falsification of Vitalism Vitalism was a doctrine that dictated that organic molecules In 1828, Frederick Woehler disproved the theory of vitalism could only be synthesized by living systems by artificially synthesizing an organic molecule Living organisms were thought to possess a “vital force” He heated an inorganic salt (ammonium cyanate) under that was required to manufacture organic molecules laboratory conditions to produce urea (organic)