Carbohydrates Notes PDF

CARBOHYDRAT ES Prepared by: Emmanuel Rod V. Fudalan BS Biology – Mindanao State University, Marawi City (1994) MA in Science Education- Holy Name University (2002) Juris Doctor – University of Bohol College of Law (2019) CARBOHYDRATES – commonly referred to as sugars and starches - are...

CARBOHYDRAT ES Prepared by: Emmanuel Rod V. Fudalan BS Biology – Mindanao State University, Marawi City (1994) MA in Science Education- Holy Name University (2002) Juris Doctor – University of Bohol College of Law (2019) CARBOHYDRATES – commonly referred to as sugars and starches - are produced in plants and are important source of energy for animals. MONOSACCHARIDES – simple sugar (simplest carbohydrates) - examples: honey (consists of glucose and fructose) - glucose contains an aldehyde at one end - fructose contains a ketone - have 3-6 carbon atoms in a chain with a carbonyl group located at one end while the rest of the carbon atoms has a hydroxyl group Common Monosaccharides: Glucose – also called dextrose ; blood sugar; most abundant monosaccharide; provide energy for the cell - normal glucose level range is 70-110 mg/dL ; excess glucose is converted into glycogen Galactose – one of the two monosaccharides that form the lactose Disaccharides- white, crystalline, sweet and solid. Formed by the combination of two monosaccharides and they are too large to pass the cell membrane. Hydrolysis process results to two monosaccharides. 3 common disaccharides: a. sucrose – very soluble in water; not a reducing sugar; sugar used in the home; also known as cane sugar; it is commercially produced from sugar cane and sugar beets; it also occurs in sorghum, pineapple and carrot roots. When glucose reacts with fructose, the products are sucrose and water. b. maltose – fairly soluble; commonly known as malt sugar; present in germinating grain; produced commercially by the hydrolysis of starch. c. lactose- slightly soluble; known as milk sugar; it has an animal origin; when fermented by bacteria, it forms lactic acid which makes it sour; used in high calcium diets and in infant foods; can be used for increasing calorie intake without adding much sweetness; found in the urine of pregnant women since it gives a positive test with Cu2+ complex ions. Sucrose and maltose- will undergo fermentation when yeast is added because it contains the enzymes sucrase and maltase Lactose- will not ferment when yeast is added because yeast does not contain lactase Cyclamates- marketed in 1950 but after 1969 findings that large doses can caused cancer in rats, they were banned in USA but still used in Canada. Polysaccharides- polymers of monosaccharides; when it is hydrolyze it produces many molecules of monosaccharides. Comparison of Polysaccharides with Monosaccharides and Disaccharides Property Monosaccharides and Polysaccharides Disaccharides Taste - sweet - tasteless Solubility in water - soluble - insoluble Size of particles - pass through a membrane - do not pass through a membrane Starch – stored energy of plants; a mixture of amylopectin and amylase ; insoluble in water. - when place in boiling water, the granules rupture forming a paste that gels on cooling. - when it is hydrolyzed, it forms dextrins then maltose and finally glucose - examples are: amylose and amylopectin Cellulose- supporting and structural substance of plants (wood, cotton and paper); cannot be digested in human digestive system but it serve a purpose when eaten with other foods cause it prevents constipation. - used to make rayon, where wood pulp is converted into a viscous liquid called viscose by treatment with sodium hydroxide and carbon disulphide Glycogen- present in the body and is stored in the liver and the muscles where it serves as a reserve supply of glucose ; formed in the body from molecules of glucose (glycogenesis) when it is hydrolyzed into glucose, the process is called glycogenolysis Dextrin- produced during hydrolysis of starch; intermediate between starch and maltose. - used in the preparation of adhesives (glue on the back of postage stamp) - also used when there is digestion problem of starch as with infants and elderly persons. Heparin- used as blood anticoagulant; inactivates thrombin and other blood clotting agents - strongest organic acid present in the body Dextran- used as blood extenders to hold water in the bloodstream and help prevent drops in blood volume and blood pressure. - grow on the surface of our teeth and act as glue where bacteria adheres causing dental plaque - bacteria Streptoccocus mutans embedded in it will use fructose for lactic acid fermentation causing a decrease in pH on the tooth surface thereby resulting to tooth decay. Carbohydrate Derivatives: Glycosaminoglycans – a gel-like that acts as a lubricant, making them key components in connective tissue and joints. Hyaluronate – lubricates joints and the vitreous humor of the eye Chondroitin – component of cartilage and tendons Heparin – stored in the cells of the liver that prevents blood clotting Chitin – found in the exoskeletons of lobsters, crabs and shrimp GLUCOSE – found in the urine of patients suffering from diabetes mellitus - glycosuria (presence of glucose in the urine) FRUCTOSE – most sweetest; most soluble - FRUCTOSEMIA (fructose intolerance); an inherited disease due to deficiency of enzyme; an infant will experience vomiting, hypoglycaemia and severe malnutrition. Infant must have a low – fructose diet. - when undergo reduction reaction it produces mixture of mannitol and sorbitol. - mannitol is used for treatment of malignant brain tumors. ALDOHEXOSES – when undergo reduction reaction, sorbitol is formed that causes cataracts due to diabetes THAT IS ALL FOR NOW