Carbohydrates

Carbohydrates

1. Part of the organic biomolecules

2. Functions

   • Precursors
     • Of certain lipids, amino acids, purines, pyramids & vitamins
   • Structural
     • Ex: cellulose in plants, bacterias & fungi
   • Energy
     • Ex: glycogen broken down
   • Reserve
     • Ex: glycogen
   • Recognition Signals
     • Involved in cell recognition
       • Ex: coagulation, hormone recognition

3. Bonds

   • Glycosidic Bond
     • -Covalent bond, joins a carbohydrate to another group, which may or may not be another carbohydrate

4. Chemical reactions

   • Reduction
     • Produces sugar alcohol
       • Alditols
   • Esterification
     • Usually performed by treating the carbohydrate with an acid chloride or an acid anhydride in the presence of a base
   • Mutarotation
     • Conversion between alpha and beta forms when monosaccharides are dissolved in water
   • Oxidation
     • Presence of oxidizing agents monosaccharides pass through several oxidation rxn.’s
       • Produce
         • Uronic acid
         • Aldaric acid
         • Aldonic acid

5. Nomenclature

6. Classification

7. Isomerism

   • L and D isomers
     • - Fisher projection The -OH on the chiral carbon farthest from the carbonyl group
       • LEFT L-isomer
       • RIGHT D-isomer
   • α and β anomers
     • - Haworth structure The -OH on the first chiral carbon
       • UP β-anomer
       • DOWN α-anomer

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