Carbohydrate Biochemistry PDF

Lec. 1 Biochemistry (1) Carbohydrate Definition: Carbohydrates are aldehyde or ketone derivatives of polyhydric alcohols or any substance derived from them. Importance of carbohydrates: 1. Carbohydrate are widely distributed both in pl...

Lec. 1 Biochemistry (1) Carbohydrate Definition: Carbohydrates are aldehyde or ketone derivatives of polyhydric alcohols or any substance derived from them. Importance of carbohydrates: 1. Carbohydrate are widely distributed both in plants and animal tissues, In plants they are produced by photosynthesis. 2. carbohydrates constitute about 60% of our diet, they are important for: a. Energy production eg: glucose b. Formation of structural elements in animal and plant cells. (glycolipids)&(glycoproteins) both enter in the structure of cell membrane and form the ground substances between tissues 1 Classification of carbohydrate: Mono saccharides Disaccharides oligosaccharides polysaccharides one sugar unit two sugar unit 3-10 sugar unit more than 10 sugar units. Mono saccharides: The simplest units on hydrolysis cannot give simplest form general formula Cn(H2o)n Nomenclature of mono saccharides: 1. According to the presence of aldehyde or ketone group a. Aldoses: mono saccharides containing aldehyde group (-CHo) the suffix -ose means aldehyde group. b. Ketoses mono saccharides containing keton group (-c=o) the suffix - ulose means ketone group. 2. According to the No. of carbon atom: Trioses Tetroses pentoses Hexoses Heptoses Mono saccharides 3C 4C 5C 6C 7C containing Classification of mono saccharides: 1-Trioses : mono saccharides containing 3C atoms 2 2-Tetroses: mono saccharides containing 4C atoms 3-Pentoses :monosaccharide containing 5C atoms Importance functions of pentoses:  Ribose and Deoxy ribose enter in the structure of nucleic acid RNA&DNA  Ribose enter in the structure of ATP&GTP and other high compound phosphate energy  Ribose phosphate & Ribulose phosphate are intermediate in the pentose phosphate path way(PPP) glucose oxidation minor pathway  -Ribose enter in the structure of coenzymes NAD&NADP and flavoproteins  Xylose intermediate in uronic acid pathway (minor of glucose oxidation pathway)  Arabinose and xylose are constituents of glycoproteins 3 4- Hexoses: mono saccharides containing 6C atoms Importance of Hexoses (Glucose):  Glucose is the most important sugar in carbohydrate  Dietary carbohydrate are absorbed to glucose  Glucose is converted to all carbohydrate in the body Glycogen, galactose, fructose and ribose  Glucose is the major source of energy in mammals Importance of Hexoses (Fructose):  It can be converted to glucose in liver  It is the main source sugar in semen Importance of Hexoses (Galactose):  It can be converted to glucose in the liver  It synthesized in mammary gland to make lactose of milk sugar Importance of Hexoses (Mannose): a. Constitute of many glycoproteins Importance of Heptoses: Formed during glucose oxidation 4