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What is nutrition. The word 'Nutrition" comes from a Latin word which means to 'nourish" or to "to feed". Nutrition covers many areas including: the science of food why people/animal choose certain foods what foods are made of the nutrients in foods how the body uses food
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What is nutrition • The word 'Nutrition" comes from a Latin word which means to 'nourish" or to "to feed". • Nutrition covers many areas including: • the science of food • why people/animal choose certain foods • what foods are made of • the nutrients in foods • how the body uses food • food digestion • food functions
Food composition • What are foods made of? • Carbohydrates • Proteins • Fats • Vitamins • Minerals • Water
Carbohydrates • Carbon, hydrogen and oxygen • Ratio H:O = 2:1 similar to water • Acetic acid, lactic acid, deoxyribose, rhamnose • Polyhydroxy aldehide or polyhydroxy keton • Primary function: • Source of energy • Located in plant and animal tissues • Simple carbohydrate- starches (grains) • Complex carbohydrate- cellulose (component of cell walls)
Carbohydrates • SOURCE OF CALORY • 55-60% of caloric intake • 1 gram yields 4 calories
Carbohydrates Simple carbohydrates • Monosaccharides • Glucose • Fructose • Galactose • Disaccharides • Sucrose (Glucose + fructose) Cane • Maltose (Glucose + Glucose) Starches • Lactose (Glucose + Galactose) Milk
Carbohydrates Complex carbohydrates • Cellulose • Ruminants require microbial fermentation to break down complex carbohydrates
Carbohydrates • Carbohydrates come from plant foods. They are the cheapest and most plentiful of all nutrients. Foods, which contain carbohydrates, are called energy foods. Carbohydrates are classified into three groups: • Sugar • Starch • fiber
Sources of carbohydrates • Sugars arefound in honey, fruit (both fresh and dried) soft drinks, milk and sugar. • Starches arefound in cereals, pasta, flour, bread, potatoes, root and pulse vegetables. • Fibers are found in fruits, vegetables and whole wheat bread.
Functions of carbohydrates • Carbohydrates provides the body with heat and energy. • Fiber helps the movement of food through the intestine. • Fiber rich and starchy foods provide a "full feeling". • Carbohydrate deficiency: • Carbohydrate deficiency diseases rarely occur, as carbohydrate is present in a wide variety of foods. • Starting material for synthesis of other type of compound e.g. fatty acid and certain amino acid • Structure of: glycolipid, glycoprotein, nucleic acid