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Carbohydrate

01402311 Biochemistry I 2nd Semester 2012 By Puttaporn Songsri 2 IMPORTANCE

• Carbohydrate = sugar = saccharides • Skeleton structures in plants and also in insects and crustaceans • Food reserves in plants and in the liver and muscles of animals • Source of energy • Lubricate skeleton joints 3 NOMENCLATURE & DEFINITION

• Hydrates of carbon = Cx(H2O)y

• Deoxyribose (C5H10O4) and rhamnose (C6H12O5) do not have the required ratio of hydrogen to oxygen. • Formaldehyde, acetic acid and lactic acid are not carbohydrates. • Nowadays broadly defines as “polyhydroxy aldehydes or ketones and their derivatives” 4 CLASSIFICATION

• Monosaccharides = simple sugars - Triose: glyceraldehyde, dihydroxyacetone - Tetrose: erythrose, erythrulose - Pentose: ribose, ribulose - Hexose: (aldose), (ketose) - Heptose 5 CLASSIFICATION

• Oligosaccharides = compound sugars - Disaccharides: Sucrose, Lactose, Maltose, Cellobiose - Trisaccharides: Raffinose - Tetrasaccharides: Stachyose 6 CLASSIFICATION

• = compound sugars - Homopolysaccharides: Starch, , Inulin, , Pectin, Chitin - Heteropolysaccharides: Hyaluronic acid, Chondroitin 7 STEREOISOMERS

• Enantiomers = mirror images of each other. • Diastereomers = not mirror images of each other. •Epimers= two diastereoisomers differ from each other at only one stereocenter. • Anomers = differ in configuration only around anomeric carboc atom (C 1) 8 Aldose and Ketose 9 Walter Norman Haworth

• English Chemist (1883-1950) • 1937 Nobel Prize in Chemistry (work on Carbohydrate and Vitamin C) 10 Anomers REACTION OF GLYCOSIDIC 11 OH GROUP • Reaction with alcohol

Glycoside 12 OXIDATION WITH ACIDS

• Gluconic acid 13 Benedict’s reagent 14 Reduction Æ sugar alcohol 15 Fermentation 16 OLIGOSACCHARIDES

• Sucrose or Saccharose 17 Sucrose

•Glc(α1Æ 2) Fru • Invertase = sucrase hydrolyze sucrose to glucose + fructose (invert sugar) • Molass = ? • Caramel = ? 18 Lactose

• Milk sugar • Lactose intolerance ? 19 Maltose

• Malt sugar • Produced by action of malt (diastase) Malt 20 21 Cellobiose

• Cellulose digestion by cellulase 22

• Isomaltose ? • Trehalose ? 23

• Homopolysaccharide - Storage : starch, glycogen - Structural : cellulose, pectin, chitin 24 Starch

• Consist of two components - Amylose (15-20%) - Amylopectin (80-85%) 25 26 Glycogen

• Animal starch Glycogen in liver cell stained with27 carmine 28 Inulin

•2Æ1 β-polyfructose 29 Cellulose

• The most abundant of all biomolecules in the biosphere • β-1,4-glucoside linkage 30 31 Pectin

• α-Polygalacturonic acid • Abundant in ripe fruits such as guava, apple and pear. • Citrus peel contain 30% pectin แยมผิวสม (marmalade) 32 33 Chitin

• Linear polymer of N-acetyl-D-glucosamine • Found in fungi and arthropod 34 Hemicellulose

• The polysaccharide component of plant cell wall s other than cellulose

Xylan 35 HETEROPOLYSACCHARIDES

• Glycosaminoglycans (mucopolysaccharide) - Hyaluronic acid found in hyaline cartilage 36 Other glycosaminoglycan

• Chondroitin • Chondroitin sulfates • Dermatan sulfate • Keratosulfate • Heparin 37 Agar-agar

• Gelatinous polysaccharide produced by certain marine red algae. • Consists of D and L- and sulfuric acid 38 PowerPoint นี้อยูที่ ชีวเคมี กําแพงแสน biochem.flas.kps.ku.ac.th