Presented by Ms P H Giri Department of Microbiology Deogiri College Aurangabad BSc F Y Semester II Paper No V Basic Biochemistry Unit 1 carbohydrates Ms Priyanka ID: 1044892
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1. Topic –carbohydratesPresented byMs. P. H. GiriDepartment of MicrobiologyDeogiri College, Aurangabad
2. B.Sc. F. Y.Semester IIPaper No. VBasic BiochemistryUnit 1 carbohydratesMs. Priyanka H. Giri
3. Unit- 1 carbohydratesIntroductionCarbohydrates, together with lipids, proteins and nucleic acids, are one of the four major classes of biologically essential organic molecules found in all living organisms. Carbohydrates, all coming from the process of photosynthesis, represent the major part of organic substance on Earth, are the most abundant organic components in the major part of fruits, vegetables, legumes and cereal grains, carry out many functions in all living organisms and are the major energy source for humans.
4. They act as storehouses of chemical energy (glucose, starch, glycogen). Carbohydrates make up about three fourths of the dry weight of plants. Less than 1% of the body weight of animals is made up of carbohydrates. They are produced in photosynthesis by condensation of CO2 and H2O in presence of light energy and the pigment chlorophyll.The name carbohydrate means hydrate of carbon and derives from the formula Cn(H2O)n OR CnH2nOn OR (CH2O)n .Not all carbohydrates, however, have this general formula. Some contain too few oxygen atoms to fit this formula, and some others contain too many oxygen. The carbohydrates are a major source of metabolic energy, both for plants and for animals that depend on plants for food. Carbohydrates are called saccharides or if they are relatively small, sugars.
5. DEFINITION :Carbohydrates are polyhydroxylated aldehydes or ketones and their derivatives. The word "carbohydrate" includes polymers and other compounds synthesized from poly-hydroxylated aldehyde and ketone.The term generated from carbon and hydrate; though some also contain nitrogen, phosphorus, or sulfur. Chemically, carbohydrates are molecules that are composed of carbon, along with hydrogen and oxygen- usually in the same ratio as that found in water (H2O).The ration of C:H:O is 1:2:1.
6. Classification of carbohydrates Following table shows different classifications of carbohydrates
7. Classifications based on number of sugar units in total chain:(a) Monosaccharides (simple sugars, composed of one monosaccharides):example: Glucose. (b) Disaccharides (composed of two monosaccharides): example: Sucrose, Lactose, Maltose. (c) Oligosaccharides (consisting of 3–10 monosaccharides)Example: Disaccharides, trisaccharides, tetrasaccharides. (d) Polysaccharides (consisting of more than 10 monosaccharides): example: Starch, Glycogen.
8. a) Monosaccharides (simple sugars):Monosaccharides are colorless, crystalline solids, sweet to the taste, although they often crystallize with difficulty. Because hydrogen bonding is possible between their polar OH groups and water, all monosaccharides are very soluble in water.Monosaccharides have the general formula CnH2nOn with one of the carbons being the carbonyl group of either an aldehyde or a ketone. The most common monosaccharides have three to eight carbon atoms. The suffix-ose indicates that a molecule is a carbohydrate, and the prefixes tri-, tetr-, pent-, and so forth indicate the number of carbon atoms in the chain.
9. Monosaccharides containing an aldehyde group are classified as aldoses; those containing a ketone group are classified as ketoses. A ketose can also be indicated with the suffix ulose; thus, a five- carbon ketose is also termed a Pentulose.
10. The simplest and smallest unit of the carbohydrates is the monosaccharide, (mono = one, saccharide = sugar) from which disaccharides, oligosaccharides, and polysaccharides are constructed. Monosaccharides are either aldehydes or ketones, with one or more hydroxyl groups. The simplest monosaccharides are the two three-carbon trioses: glyceraldehyde, an aldose, and dihydroxyacetone, a ketose.
11. Simple monosaccharides with four, five, six, and seven carbon atoms are called tetroses, pentoses, hexoses, and heptoses, respectively. ; the six-carbon monosaccharides glucose (aldohexose) and fructose (a keto hexose) have five hydroxyl groups.
12. Fructose Glucose
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15. Some concepts:1) Chiral Carbon atom/ Assymetric carbon atom:Carbon atom having four different groups attached to it is called chiral carbon.
16. How many chiral carbons are there?
17. How many chiral carbons are there?
18. How many chiral carbons are there?
19. 2) Anomeric carbon: It is the carbon derived from the cabonyl carbon compound (the ketone or aldehyde functional group) of the open chain form of the carbohydrate molecule.
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21. 3)Penaltimate carbon:The penultimate (second to last carbon) carbon is the last chiral carbon of the chain. The alcohol group attached to this carbon is that which attacks the carbonyl during cyclization of a sugar.
22. 4) D and L form of sugar:
23. 5) Alpha and beta form of sugar: