Page 1 :
9. BIOMOLECULES, , Biomolecules are chemical compounds found in, living organisms., They include organic and inorganic compounds., , ANALYSIS OF CHEMICAL COMPOSITION, IN A TISSUE, , ¢ Grind a living tissue (vegetable or piece, of liver etc.) in trichloroacetic acid, (CI3CCOOH) to get thick slurry., , ¢ Strain this through a cheesecloth or, cotton to get 2 fractions such as filtrate, (acid-soluble pool) and the retentate, (acid-insoluble fraction)., , ¢ The filtrate contains biomicromolecules, (biomolecules having molecular weight, less than 1000 Dalton)., , ¢ The retentate contains, biomacromolecules (biomolecules, having molecular weight higher than, 1000 Dalton).
Page 2 :
Analysis of inorganic compounds, , ¢ Weigh a living tissue (wet weight) and it, is dried (dry weight) to evaporate water., , ¢ It is fully burnt to oxidize all carbon, compounds to gaseous form (CO2 &, water vapour). It forms ash., , ¢ The ash contains inorganic elements, (Ca, Mg, Na, K etc.) & inorganic, compounds (S042-, PO43-, NaCl, CaCO3, , , , , , , , , , , , , , , , , , , , , , , , , , etc.)., Comparison of Elements in Non-living & Living Matter, % Weight of, Element, Earth's crust | Human body, , Hydrogen (H) 0.14 0.5, Carbon (C) 0.03 18.5, Oxygen (0) 46.6 65.0, Nitrogen (N) Very little 3.3, Sulphur (S) 0.03 0.3, Sodium (Na) 2.8 0.2, Calcium (Ca) 3.6 1.5, Magnesium (Mg) 2.1 0.1, Silicon (Si) 27.7 Negligible
Page 3 :
BIOMICROMOLECULES, (MICROMOLECULES OR, BIOMOLECULES), , Molecular weight of micromolecules found in the, acid soluble pool ranges from 18 to 800 Dalton, (Da). The acid soluble pool represents the, cytoplasmic composition., , They include amino acids, sugars, nitrogen bases,, lipids etc., , , , 1. AMINO ACIDS, , , , ¢ They are the compounds formed of an, amino group (-NH2), an acid group (COOH), H & a variable group (R)., , ¢ —-NH2 & —-COOH are attached to the, same carbon atom (a-carbon). So, they, are called a-amino acids., , ¢ They are substituted methanes., , oun qoon goon qocn, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , =e wee a — os, R H CH, CH-OH, Glycine Alanine Serine, , 20 types of amino acids are used for protein, synthesis. They include
Page 4 :
20 types of amino acids are used for protein, synthesis. They include, , ¢ Acidic amino acids: e.g. Glutamic acid,, Aspartic acid., , ¢ Basic amino acids: e.g. Lysine, Arginine., ¢ Neutral amino acids: e.g. Valine., , Some amino acids are aromatic. E.g. tyrosine,, phenyl alanine and tryptophan., Amino acids are 2 types:, , e Essential amino acids: They cannot be, synthesized by the body and should be, supplied through diet. E.g. Lysine,, leucine, isoleucine, tryptophan etc., , ¢ Non-essential amino acids: They can be, synthesized by the body. E.g. Glycine,, alanine, serine, arginine etc., , In amino acids, -NH2 & —COOH have ionizable, nature. So, structure of amino acids changes in, solutions of different pH.
Page 5 :
If both -NH2 & —COOH are ionized, it is called, Zwitterion., , R R R, | + | . ' ., H.N-CH- COOH == H,N-CH- COO == H,N-CH-COO, uu. ——", Zwitterionic form, , 2. LIPIDS, , , , Water insoluble., Contain C, H & O but number of oxygen atoms is, less.
