Chemistry of Carbohydrates PDF

Okay, here is the transcription of the handwritten document you sent, formatted as markdown. ### Biomolecules Class Monosaccharides are classified based on functional groups. ### Chemistry of Carbohydrates Carbohydrates are polyhydroxyl aldehydes or ketones or compounds that yield these on hydroly...

Okay, here is the transcription of the handwritten document you sent, formatted as markdown. ### Biomolecules Class Monosaccharides are classified based on functional groups. ### Chemistry of Carbohydrates Carbohydrates are polyhydroxyl aldehydes or ketones or compounds that yield these on hydrolysis. | | | | | :--------------- | :-------- | :-------------------------------------------------------- | | $H$ | | Generally, carbohydrates are classified based on the number of monosaccharide units they contain | | $H-C=O$ | $H-C-OH$ | | | $H-C-OH$ | $C=O$ | | | $OH-C-H$ | $OH-C-H$ | | | $H-C-OH$ | $H-C-OH$ | Monosaccharides are the building blocks of all carbohydrates and they do not yield other simpler carbohydrate forms. | | $H-C-OH$ | $H-C-OH$ | | | $H-C-OH$ | $H$ | | | Glucose | Fructose | | | (Polyhydroxyl aldehyde) | (Poly hydroxyl ketone) | The general formula is $(CH_2O)_n$. | **Disaccharides:** They yield two monosaccharide units when hydrolyzed, e.g., sucrose, maltose, lactose. The general formula is $C_{12}H_{22}O_{11}$. **Oligosaccharides:** There are carbohydrates which undergo hydrolysis to 3 to 10 monosaccharide units. **Polysaccharides:** These are carbohydrates which yield more than 10 monosaccharide units $(C_6H_{10}O_5)_n$. Number of carbons they contain: * 3 - Triose * 4 - Tetrose * 5 - Pentose * 6 - Hexose Starch is an example of homopolysaccharides. Heteropolysaccharides are made up of repeating units of different types of monosaccharides. | No. of Carbohydrates | Aldose | Ketose | | :------------------- | :-------------------- | :------------------- | | Triose | Glyceraldehyde | Dihydroxyacetone | | Tetrose | Erythrose | Erythrulose | | Pentose | Ribose, Xylose, Arabinose | Ribulose | | Hexose | Glucose, Mannose, Galactose | Fructose | | Heptose | Sedoheptulose | Sedoheptulose(Ketose) | Classification of Polysaccharides: 1. Homopolysaccharides: They are made up of repeating units of the same type of monosaccharide, e.g., starch, glycogen, cellulose. 2. Heteropolysaccharides: They are made up of repeating units of different types. Biochemical/Function of ... #### Chemistry of Carbohydrates Continued: Stereoisomers are compounds which have the same elemental composition and the same connectivity of atoms but differ in spatial arrangements. Stereoisomerism occurs due to the presence of the chiral center (asymmetric carbon). Chiral carbons are attached to four different functional groups. **Van Hoff's Rule of n:** The number of stereoisomers that a compound has is $2^n$, where n is the number of chiral centers. Enantiomers are stereoisomers that are non-superimposable mirror images of each other. Diastereomers are stereoisomers that are not mirror images of one another. Classification of /Polysaccharide Classification of Monosaccharides!: 1. Based on the functional group. 2. Based on the number of carbons. 3. Based on the orientation of the penultimate carbon (the naming of the compound.) Stereoisomers of monosaccharides are classified as either D or L sugars depending on the orientation of the H and OH groups on the penultimate carbon. Molecular structures of carbohydrates including D-Glucose, L-Glucose, D-Allose and L-Allose. All molecules are made of six-carbon chains with several hydroxyl groups. Optical activity is the ability of a substance to rotate plane polarized light when it is passed through a solution of that substance. Stereoisomers or compounds which contain chiral carbon exhibit optical activity. Practically, D-glucose for example can rotate plane-polarized. The body metabolizes mainly D-sugars. The enzymes that act on monosaccharides are stereospecific and L-sugars are used as sweeteners. Fructoses are keto aldohexoses, which do the exact opposite on the optical activity. * D-fructose rotates light to the left. * L-fructose rotates plane-polarized light to the right. Enantiomers have equal and opposite optical activity. * \+ 52.7 rotation for D-glucose. * \- 52.7 rotation for L-glucose. **Racemic Mixtures** A racemic mixture is an equimolar mixture of two enantiomers which are non-superimposable in a solution. The optical activity of a racemic mixture is 0 because the extent to which the D-compound is rotated is the same as that to which the L-compound is rotated, and so they cancel each other out. **Resolution of Racemic Mixtures** It is the process of separating out two enantiomers from a mixture; crystallization of D and L enantiomers out of the mixture. Diastereomers that differ from each other in the orientation of only one chiral carbon are called epimers. Glucose has 4 epimers and 16 diastereomers. Molecular structures of CHO, of D-Glucose , 3rd epimer of D- glucose (D-Allose), 2nd epimer of D-glucose (D-Mannose), 4th epimer of D-glucose (D-Gulose), 5th epimer of D-glucose(D-idose) D-mannose and D-Galactose are the Glucose Epimers found in the body Open Chain Structure Fischer Projection The fifth carbon interacts with the first carbon (the oxygen leaves the 1st carbon) and creates a covalent bond with the fifth Ring Structure or Fischer Projection Pyran ring Structure on which glucose is based. It is also known as Harvard's projection The ring structure of glucose is called pyranose. The 1st carbon ring become a chiral carbon The pyranose glucose can take two forms which interchanging the H and OH where OH is down, it is known of α-glucose and when it is up it is known as β-glucose. Anomerism Anomers are Stereoisomers which differ from one another only on the orientation of the carbon with the functional group also known as Anomeric Carbon. In Aldohexoses it is on the number one Carbon e.g. α-D-glucose & β-D glucose They have a different rotation which are both to the right α-D-glucose and β-D glucose structures. **Mutarotation** *The change in the optical activity reflect a solution of* Sugar undergoes welfare the solution of sugar has been, placed in solution over a long period of time is called Mata notation If occurs due to spontaneous conversion of the sugar molecule Enediol formation / Tautomerization *Lobry De Bruyn Van Ekenstein formation* Tautomerism is the transformation between two isomers from one form usually between a Keto and an enol, It is the interconversion of two somers eng (keto $ enol) Such that both isomers exist simultaneously in an equilibrium with one another. It occurs due to movement of one Hydrogen atom from one carbon to another When monosaccharides (e.g. glucose) are placed in an alkaline solution, they undergo tautomerization to form an enediol and other isomers of glucose – mainly fructose and mannose. This interconversion of monosaccharides through a common enediol form is known as Lobry de Bruyn–Van Ekenstein transformation. 2. **Osazone formation** They are crystalline derivatives of sugars which are formed when sugar is placed in a solution of excess phenylhydrazine and acetic acid Osazones have characteristic shapes, a melting point and are used in the identification of sugars. -Glucose crystals needle-shaped and appear like bundles of hay. Maltosazone crystals → Petal-shaped & Sunflower *otto* Lactosazone crystals→ Cotton balls or pin Cushion. 3. **Furfural formation (dehydration)** why Monosaccharides react with conc mineral acids by HI they become dehydrated by losing *3504* and forming furfurals hexoses form hydroxyl methyl furfural 1. **Idourante acid present in the body** Furfurals React with alcohols and this serves as the basis for some tests for monosaccharides reg in Mollachus test furfurals React with of Napthol to give a red Violet ring This test is non-specifies for all Sugeres in sehwarnotts test resorcard 2. **Oxidation** formation of sugeric acids The monosaccharides sugares undergo oxidation with Hypobromous acid * Accumulate of sugar alcohols in the eye which attracts water molecules | Monosaccharide | Aldonic | Uronic | Saccharic | | :------------- | :--------- | :--------- | :------------ | | Glucose | Gluconic | Glucoronic | Glucosaccharic | | Mannose | Mannonic | Mannoronie | Manosaccharic | | Galactose | Galactonic | Galactoramic | Galactosaccharic | *Sugar Alcohol* *Mild oxidation using* *strong oxidation & reduction* 5. **Reduction(formation of suger alcohol’s Monosaccharides undergo reduction usng sodium amalgam to form corresponding alcohol’s** Glucose forms Sobitol Galactose forms Galactitolar Dukiol Mamose forms mantel Formation of jodo comoundiwhen monosacrades Read with Hydrogen Rodide *H1* They rese all the oxigen in their carbon chain and beсоmе and replaced