Cogno Lecture 1 PDF

## Primary Metabolites - **Carbohydrates** - **Starch** - **Components of Starch:** - **Amylose** - polysaccharide of long unbranched chain of 1,4 linked glucose residues - soluble in water - gives clear blue colour with iodine...

## Primary Metabolites - **Carbohydrates** - **Starch** - **Components of Starch:** - **Amylose** - polysaccharide of long unbranched chain of 1,4 linked glucose residues - soluble in water - gives clear blue colour with iodine - forms inner layer of starch granule - forms 20% of the starch granule - **Amylopectin** - polysaccharide of long branched chain of 1,4 and 1,6 linked glucose residues - forms the outer layer of the starch granule - Forms 80% of the starch granule - Gives bluish black ppt. With iodine - Insoluble in water but swells in it - **Properties of Starch** - Insoluble in cold water and organic solvents - Forms Collodial solution on boiling - Undergo gelatinisation on cooling and when treated with caustic potash and conc chloral hydrate solution - Gives blue colour with iodine solution due to presence of amylose that has strong affinity for iodine - **Uses of Starch** - Tablet disintegrant - Lubricant for surgeon's gloves - Suspending agent for barium meals - Intidote for iodine poisoning - Starting material for dextrose and dextrin - **Dextrin** - Formed from starch moistened with dilacids and heated to 110° - Prepared from corn starch in the United States - Prepared from potato starch in Europe - **Uses of dextrin** - Adhesive for sizing cloth or paper - Cloth printing - Crispness of food - **Mucilage** - heterogenous Polysaccharide - linseed possess mucilage - it turns red when ruthenium red reagent added to it - **Inulin** - Gives no colour with iodine - Gives fructose in it's hydrolysis with acids or inulinase enzyme - soluble in hot Water - **Sucrose** - it's a disccharide that by hydrolysis yields glucose & fructose - Gives deep red colour on warming with HCL & resorcinol - **Protein** - **Nitrogenous organic compound** - Found in the form of amorphous masses or small particles called aleurone grains that are found in seeds - **Aleurone grains** - **Ground substance** - **Crystalloid** - yellow - **Amorphous protein soluble in water** - Formed of albumin which is hardly soluble in water - Stained brown with iodine solution - Stained red with Millon's reagent - Insoluble in water - **Globoid** - colourless - Formed of globin combined with Ca and Mg salts of inositol phosphoric acid - **Staining of aleurone grain with picric acid and eosin** - **Properties of proteins** - **Insoluble in organic solvents and in alcohols** - **Precipitated in salts of heavy metals and in tannic acid** - **Precipitated on** - Marked change on PH - Heating 60°c-80°c - High concentration of mineral salts - **Tests of proteins** - **Millon's reagent (mercuric nitrate and nitrous acid)** - On heating the sample with the reagent for two minutes at 95°c-red ppt is formed - **Biruet's test (NaoH.hydrated CuO4.potassium sodium tartrate)** - Forms violet-coloured complexes - **Lipids** - **Fat and fat-like substances** - Fats and oils (fixed and volatile) may become rancid by keeping due to oxidation by air oxygen and bacterial putrefaction - Insoluble in water - Soluble in organic solvents - **Fixed oils and fats** - **Mixture of esters of fatty acids with trihydric alcohol usually called glycerides** - Occur in seeds - Greasy and non-volatile at ordinary temperature - Leaves permanent stain on paper - Oil are rich of liquid glycerides - Fals are rich of solid glycerides - **Oils are classified to the ability of the oil to absorb oxygen and amount and degree of unsaturation of fatty acids into:** - **Drying oil- linseed oil** - **Semi-drying oil - canola oil** - **Non-drying oil - olive oil** - **Saponification** - Saturated solution of potash (KOH) and strong ammonia solution slowly soponifies fats and fixed oils - soap crystals is observed - **Detection of fixed oil** - **Sudan III - coloured red** - **Osmic acid - coloured black**