Biomolecules - - . . PM . .
Properties of Water • Adhesion and cohesion property • High latent heat of vaporisation • High melting and boiling point • Universal solvent • Specific heat capacity . Primary and Secondary Metabolites Most plants, fungi and other microbes synthesizes a number of organic compounds called as metabolites which are intermediates and products of metabolism. The term metabolite is usually restricted to small molecules. It can be catergorized into two types namely primary and secondary metabolites based on their role in metabolic process (Figure .
). Figure . : Synthesis of metabolites during growth Primary metabolites are those that are required for the basic metabolic processes like photosynthesis, respiration, protein and lipid metabolism of living organisms. Secondary metabolites does not show any direct function in growth and development of organisms.
Morphine is the first alkaloid to be found. It comes from the plant Opium poppy ( Papaver somniferum ). It is used as a pain reliever in patients with severe pain levels and cough suppressant. Figure .
: Water molecule O H H Covalent Bond Manganese is required for activity of enzyme needed for synthesis of oligosaccharides and glycoproteins. Molybdenum is necessary for fixation of nitrogen by enzyme nitrogenase. Component % of the total cellular mass Water Proteins Carbohydrates Lipids Nucleic acids Ions . Water Water is the most abundant component in living organisms.
Life on earth is inevitably linked to water. Water makes up % of human cell and upto % of mass of a plant cell (Figure . ). % Chemical % Water % % ( %) Proteins ( %) Small molecules ( %) RNA ( %) Phospholipids ( %) DNA ( %) Polysacharides Figure .
: Percentage of biomolecules in cell . . Chemistry of Water Water is a tiny polar molecule that can readily pass through membranes. Two electronegative atoms of oxygen share a hydrogen bonds of two water molecule.
Thus, they can stick together by cohesion and results in lattice formation (Figure . ). - - . .
PM form large and complex molecules called macromolecules . These include four main classes – carbohydrates, lipids, proteins and nucleic acids. All macromolecules except lipids are formed by the process of polymerisation, a process in which repeating subunits termed monomers are bound into chains of different lengths. These chains of monomers are called polymers .
. Carbohydrates Carbohydrates are organic compounds made of carbon and water. Thus one molecule of water combines with a carbon atom to form CH O and is repeated several (n) times to form (CH O) n where n is an integer ranging from – . These are also called as saccharides .
The common term sugar refers to a simple carbohydrate such as a monosaccharide or disaccharide that tastes sweet are soluble in water (Figure . ). . .
Monosaccharides – The Simple Sugars Monosaccharides are relatively small molecules constituting single sugar unit. Metabolites Examples Primary Enzymes protease, lipase, peroxidase Amino acid proline, leucine Organic acid acetic acid, lactic acid Vitamins A, B, C Secondary Pigments carotenoids, anthocyanins Alkaloids morphine, codeine Essential oil lemon grass oil, rose oil Toxins abrin, ricin Lectins concanavalin A Drugs vinblastin, curcumin Polymeric substances rubber, gums, cellulose . . Organic Molecules Organic molecules may be small and simple.
These simple molecules assemble and