CNGNGE JOHN MCMURRY CHAPTER 21 Biomolecules: Carbohydrates T HI R D EDITION Organic Chemistry with Biological applications
CHAPTER 21 Biomolecules: Carbohydrates
Carbohydrates Carbohydrate Broad class of polyhydroxylated aldehydes and ketones commonly called sugars 。 Synthesized by green plants during photosynthesis 重 Name derived from glucose Glucose was the first simple carbohydrate obtained in pure form ·brae0Y8ot8e8h6n是eoe,as ~50%of the dry weight of earth's biomass consists of glucose polymers HO HH OH O H-C-OH hO. HO-C-H or H-C-OH HHH OHH OH H-C-OH CH2OH Glucose(dextrose), a pentahydroxyhexanal
Carbohydrate ▪ Broad class of polyhydroxylated aldehydes and ketones commonly called sugars ▪ Synthesized by green plants during photosynthesis ▪ Name derived from glucose ▪ Glucose was the first simple carbohydrate obtained in pure form ▪ Molecular formula of glucose, C6H12O6 , was thought to be a “hydrate of carbon, C6 (H2O)6 ” ▪ ~ 50% of the dry weight of earth’s biomass consists of glucose polymers Carbohydrates
Carbohydrates Carbohydrates act as chemical intermediates by which solar energy is stored and used to support life on earth 6C02+6H20 Sunlight 602+C6H1206 → Cellulose,starch Glucose
Carbohydrates act as chemical intermediates by which solar energy is stored and used to support life on earth Carbohydrates
21-1 Classification of Carbohydrates Carbohydrates are classed as simple or complex 量 Simple sugars,or monosaccharides Carbohydrates like glucose and fructose that cannot be converted into more simple sugars by hydrolysis Complex carbohydrates Made up of two or more simple sugars Sucrose is a disaccharide comprised of one glucose and one fructose Cellulose is a polysaccharide comprised of several thousand linked glucose units CH2OH HO HOCH2- Hao 1Glucose 1Fructose CH2OH HOHO Sucrose (a disaccharide) CH2OH 0 CH2OH 0 -3000 Glucose HO OH HO 一0之 OH Cellulose (a polysaccharide)
Carbohydrates are classed as simple or complex ▪ Simple sugars , or monosaccharides ▪ Carbohydrates like glucose and fructose that cannot be converted into more simple sugars by hydrolysis ▪ Complex carbohydrates ▪ Made up of two or more simple sugars ▪ Sucrose is a disaccharide comprised of one glucose and one fructose ▪ Cellulose is a polysaccharide comprised of several thousand linked glucose units 21-1 Classification of Carbohydrates
Classification of Carbohydrates Monosaccharides are classified as aldoses or ketoses -ose suffix designates a carbohydrate aldo-prefix identifies an aldehyde carbonyl group in the sugar keto-prefix identifies a ketone carbonyl group in the sugar Number of carbons indicated by the numerical prefix tri-, tetra-,pent-,hex- CH2OH Hc≥0 CH2OH C=0 H-C-OH C=0 Hc0 HO-C-H HO-C-H HO-C-H H-C-OH H-C-OH H-C-OH H-C-OH H-C-OH H-C-OH H-C-OH H-C-OH H-C-OH H-C-OH CH2OH CH2OH CH2OH CH2OH Glucose Fructose Ribose Sedoheptulose (an aldohexose) (a ketohexose) (an aldopentose】 (a ketoheptose)
Monosaccharides are classified as aldoses or ketoses ▪ -ose suffix designates a carbohydrate ▪ aldo- prefix identifies an aldehyde carbonyl group in the sugar ▪ keto- prefix identifies a ketone carbonyl group in the sugar ▪ Number of carbons indicated by the numerical prefix tri-, tetra-, pent-, hexClassification of Carbohydrates