Structure & Function of Carbohydrates : Structure & Function of Carbohydrates Dr. Deryck D. Pattron, Ph.D. Carbohydrates : Carbohydrates Carbohydrates consist of the elements carbon (C), hydrogen (H) and oxygen (O) with a ratio of hydrogen twice that of carbon and oxygen. Carbohydrates : Carbohydrates 40% and 60% of total calories should come from complex carbohydrates (starches) and naturally occurring sugars. Carbohydrates : Carbohydrates Carbohydrates include sugars, starches, cellulose and many other compounds found in living organisms. In their basic form, carbohydrates are simple sugars or monosaccharides. Carbohydrates : Carbohydrates These simple sugars can combine with each other to form more complex carbohydrates. The combination of two simple sugars is a disaccharide. Carbohydrate : Carbohydrate Carbohydrates consisting of two to ten simple sugars are called oligosaccharides, and those with a larger number are called polysaccharides. Monosaccharides : Monosaccharides Classified by the number of carbons in the saccharide unit.
Pentose (5-carbons) e.g. fructose.
Hexoses (6-carbons) e.g. glucose and galactose. Disaccharide : Disaccharide Two monosaccharides linked together
E.g. sucrose or table sugar
E.g. lactose = glucose + galactose
E.g. maltose = glucose + glucose Oligosaccharide : Oligosaccharide Three-ten monosaccharides linked together
Raffinose (3 carbon)
Stachyose (4 carbon) Polysaccharides : Polysaccharides Many monosaccharides linked together in long chains
Chitin Polysaccharide : Polysaccharide Branched Polysaccharide : Branched Polysaccharide Branched: storage of energy
starch - energy storage in plants (wheat, potatoes)
glycogen - energy storage in animals (liver, muscle) Linear Polysaccharide : Linear Polysaccharide Linear: structural material
cellulose - found in cotton, plant cell walls.
chitin-found in the exoskeleton of insects. Cellulose Molecular Structure : Cellulose Molecular Structure Cellulose Structure : Cellulose Structure Function of Carbohydrates : Function of Carbohydrates Supplies energy-body, brain and the nervous system
Source of carbon in metabolic processes
Storage form of energy
Structural elements of cells and tissues Side effects of Carbohydrates : Side effects of Carbohydrates Excessive carbohydrates can cause an increase in the total caloric intake, causing obesity and pancreatic cancer in women.
Deficient carbohydrates can cause a lack of calories (malnutrition), or excessive intake of fats to make up the calories.
Low-fat, high-carbohydrate diets contribute to hyperinsulinemia and hypertriglyceridemia. References : References Harper, A. (1999). "Defining the Essentiality of Nutrients." In Modern Nutrition in Health and Disease, 9th edition, ed. M. E. Shills, et al. Baltimore, MD: Williams and Wilkins.
Morrison, Gail, and Hark, Lisa (1999). Medical Nutrition and Disease, 2nd edition. Cambridge, MA: Blackwell Science.
Subar, A. F., et al. (1998). "Dietary Sources of Nutrients in the U.S. Diet, 1989 to 1991." Journal of the American Dietetic Association 98:537.
Wardlaw, Gordon M., and Kessel, Margaret (2002). Perspectives in Nutrition, 5th edition. Boston: McGraw-Hill. Slide 19: THE END