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Biomolecules — Chemistry STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 ScienceChemistryBiomolecules4 Marks
Question
Define the following with an example of each:
(a) Polysaccharides
(b) Denatured protein
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Answer

(a) Polysaccharides : Polysaccharides are formed by the polymerization of monosaccharides. Thus these are neutral polymeric compounds in which a large number of monosaccharide units are joined by glycosidic linkage in a long linear or branched structure. They are, naturally occurring, colourless, tasteless (not sweet), amorphous powders. They have the general formula $\left( C _6 H _{10} O _5\right)_n$. Some important polysaccharides are :
Cellulose, starch, glycogen, gums and pectin.
(b) Denaturation of Proteins : A protein found in a biological system having a unique 3D structure and specific biological activity is called a native protein. Various changes in the structure of protein such as pH , temperature, pressure, presence of salts or certain chemical agents can disrupt the complex three dimensional structure of the proteins. Disruption of the native structure (conformation) of a protein is called denaturation. Due to denaturation a protein loses its biological activity.

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