Carbohydrates, types carbohydrates, properties, functional groups and chemical structures, Study notes of Biology

Download Carbohydrates, types carbohydrates, properties, functional groups and chemical structures and more Study notes Biology in PDF only on Docsity! CARBOHYDRATES Mr Ndovorwi NSC1110- Introductory Biology I Learning Objectives • Explain the different roles played by carbohydrates in living systems • Classify carbohydrates into their respective categories • Discuss isomeric properties of carbohydrates • Draw structures of the most common carbohydrates • Describe the physical properties of carbohydrates • Discuss digestion of dietary carbohydrates NSC1110- Introductory Biology I Monosaccharides • * Monomer Units of Carbohydrates * Functional sugar group: Aldehyde group – aldoses Keto group – ketoses NSC1110- Introductory Biology I • Classification of Monosaccharides according to No. of carbon atoms NSC1110- Introductory Biology I Characteristics of Monosaccharides • * Colorless • * Crystalline solids • * Soluble in water • * In- soluble in non-polar solvents • * Most are sweet NSC1110- Introductory Biology I Monosaccharides: Pentoses NSC1110- Introductory Biology I (CH₂O)n n = 5 C₅H₁₀O₅ Monosaccharides: Hexoses NSC1110- Introductory Biology I (CH₂O)n n = 6 C₆H₁₂O₆ Isomerism Isomers Compounds having same chemical formula but different structural formula (CH₂O)n n = 6 C₆H₁₂O₆ NSC1110- Introductory Biology I Structures that are mirror images of each other and are designated as D- and L- sugars based on the position of –OH grp on the asymmetric carbon farthest from the carbonyl carbon Majority of sugars in humans are D-sugars Enantiomers (D- and L-Forms) HERO H—(— lh CH,OH CH,>OH p-Glyceraldehyde L-Glyceraldehyde NSC1110- Introductory Biology |  oe O.CHLOH —_—+ ; ay M : ha | NSC1110- Introductory Biology I CH2OH C O C HHO C OHH C OHH CH2OH HOH2C OH CH2OH H OH H H HO O 1 6 5 4 3 2 6 5 4 3 2 1 D-fructose (linear) -D-fructofuranose Anomers • Differ only in the configuration at the anomeric carbon NSC1110- Introductory Biology I CH,OH CH,OH HO OC OH OH On te. id O O 0 HB + 4 B #20 HO H OH OH H OH H H le a ai i H H HO H > OH H OH H H H H H OH H OH Galactose Glucose H OH H OH Lactose CH,OH CH,OH CH.OH HA) Ou O. 4H ‘5 CH,OH OH HY” + 2X H HO me Nh H OL H HO OH HO CH,OH J 5 OH H Ya O 2 H HO HO CH,OH H OH OH H Glucose Fructose H OH OH H Sucrose NSC1110- Introductory Biology | Physical Properties of Disaccharides • Soluble in water • Sweet taste • Cannot pass through the cell membrane NSC1110- Introductory Biology I Polysaccharides • Polysaccharides are polymers of 10 or more monosaccharide units • Homopolysaccharides contain a single type of monosaccharide unit. • E.g. Glycogen, Cellulose and starch • Heteropolysaccharides contain more than one type of monosaccharide unit. • E.g. Glycosaminoglycans (GAGs) NSC1110- Introductory Biology I Polysaccharide: Cellulose NSC1110- Introductory Biology I Cellulose is a structural polymer produced by plants: • It is a linear, unbranched polyer, with D-glucose units connected by β(1→4) glycosidic bonds HO HO HO ° t 0 0 | oO j}— \04 + - Oo : ; : | Oo - & Oo 4 NSC1110- Introductory Biology | -—— oO t——— 9 OH '<————— hydrogen bond OH OH Polysaccharide: Glycogen • Animals also produce a storage form of glucose called glycogen, which has a structure similar to amylopectin. NSC1110- Introductory Biology I Heteropolysaccharide: Chondroitin • Present in connective tissue NSC1110- Introductory Biology I  Many diseases associated with disorders of carbohydrate metabolism including: Diabetes mellitus Galactosemia Glycogen storage diseases Lactose intolerance The End