Carbohydrates

Carbohydrate hydrate of carbon – Cn(H2O)m Glucose -blood sugar- C6H12O6 or C6(H2O)6 Sucrose -table sugar- C12H22O11 or C12(H2O)11

Not all carbohydrates have this exact form – old habits die slow or sometimes never at all

Monosaccharides Formula CnH2nOn One carbon is either an aldehyde or ketone The suffix ose indicates that the molecule is a carbohydrate Use prefix to indicate number of carbons tri , tetr, pent, hex Aldose – contain an aldehyde group Ketose – contain a ketone group

Aldohexoses Monosaccharides Aldohexoses carbohydrates aldehyde function six carbons carbohydrates or saccharides other examples: ketotetrose, aldotriose, ketopentose

Fischer Projections Emil Fischer (late 1800’s) A B C D Side groups come out of the plane (towards you) Vertical groups go back away from you A B C D

Naming Aldotriose and aldotetrose Remember ET goes home left at T

Naming AldoPentose RAXL – Ribose, Araginose, Xylose, Lyxose Right – Top – Middle – Top/Middle

Naming Aldohexoses All Altrose Gladly Make Gum in Gallon Tanks Bottom – all right 2 up – 4x4 3 up – 2x2 like Noahs Ark 4 up – alternate

R/S and D/L R = D - dextrorotatory S = L - levarotatory D – A monosaccharide with the Penultimate OH group on the right in a Fischer Projection L - A monosaccharide with the penultimate OH group on the left in a Fischer Projection OK, so what’s a penultimate????

Ketoses * Note: The ketone is located on carbon #2 * triose tetrose pentoses Penultimate is the next To last carbon hexoses *

Amino Sugars Contain an NH2 group instead of an OH 1st three are common in nature

Cyclic structure of monsacharides It’s the hemiacetal reaction all over We draw them as Haworth Projections Practice practice practice From yahoo images

Reactions of Monosacharides Practice From yahoo images

The two Most Significant Sugars Aldose -D-glucose -The most important monosaccharide -White solid -Formula C6H12O6 - Sugar used in our bodies Ketose D-Fructose Known as “fruit sugar” Found combined with glucose in the disaccharide sucrose

Multiple Sugars Monosaccharides – Single Carbohydrate unit Disaccharides - two monosaccharides combined Oligosaccharides - three to ten monosaccharides Polsaccharide – More than ten monoscharides

Three Disaccharides Sucrose Lactose Maltose

Disaccharides * Sucrose A disaccharide One D-glucose and one D-Fructose Connected by two anomeric carbons: C-1 on glucose and C-2 on fructose linkages:  linkage on glucose and  linkage on fructose

Disaccharides * Sucrose Anomeric C are tied-up on both sugars No oxidation can occur no hemi-acetals Sucrose is a non-reducing sugar Hydrolyzed by enzymes to form a mixture of glucose and fructose - “invert sugar”

Disaccharides * Sucrose -C-1 -C-2

Disaccharides * Lactose A disaccharide One D-galactose and one D-glucose Connected by an  linkage between D-Galactose C-1 and D-Glucose C-4 Known as an -1,4 linkage Found in mammalian milk

Disaccharides -1,4 linkage Lactose

Disaccharides * Maltose A disaccharide Two D-glucose monomers Connected by an  linkage between C-1 and C-4 Known as an -1,4 linkage (two D-glucose molecules) An ingredient in most syrups “Malt sugar”

Disaccharides -1,4 linkage

Polysaccharides * Starch - Amylose Many units of -D-glucose Linkages are -1,4 (same as Maltose) Between 1000-2000 glucose units (polyglucose) Random coils or helix

Polysaccharides * Starch - Amylopectin Also many units of -D-glucose Linkages are -1,4 and -1,6 Lots of branching 20 to 25 glucose monomers in the straight chain and then branching A total of 105 to 106 glucose molecules Use Iodine (I2) to test for starches

Polysaccharides * Glycogen Animal energy storage (about 400 g in us) -D-glucose polymer Similar to amylopectin but smaller chains Linkages are -1,4 and -1,6 (branching) 10 to 20 glucose monomers in the straight chain and then branching A total of 105 to 106 glucose molecules

Polysaccharides * Cellulose Linear polymer of D-glucose Linkages are -1,4 ! The most abundant molecule in living tissues Cotton is about 95% cellulose 300 to 3000 glucose units Form fibrous rods

Polysaccharides * Cellulose We cannot digest cellulose  glucose linkages! Many bacteria and fungi have necessary enzyme Ruminant mammals carry these bacteria Termites also have necessary microorganisms