How Nutrients Become You Six Nutrient Groups – Carbohydrates – Fats – Proteins – Vitamins – Minerals – Water

Chemistry of Nutrition Elements-simplest substances Matter-takes up space; is measurable Molecule – smallest amount of substance with characteristics of the substance – made of two or more atoms bonded together COMPOUND is formed when atoms of different elements are bonded together

Functions of Nutrients Build and repair body tissues – Growth spurts, injuries, illness Regulate body processes – Circulation, digestion, absorption, metabolism Provide energy – Fuel – Carbs and fats

Energy Value of Food Kilocalorie-amount of heat required to raise one kilogram of water one degree Celsius Kilocalorie=Calories Fats=9 calories/gm Carbohydrates=4 calories/gm Protein=4 calories/gm Alcohol=7 calories/gm (no nutrient value!)

The Process of Digestion Body breaks down food into simpler substances Mechanical Digestion-chewing… Chemical Digestion – Enzymes (protein) cause chemical reactions GI Tract-25-30’ (mouth to anus) – 5-14 hours from mouth to sm. intestine

Components of GI tract Mouth-mastication, saliva Esophagus (10 “) – parallels trachea (epiglottis) – Peristalsis-moves food through Stomach (3 hours-fats take longest) – Gastric juices: HCl, enzymes, mucous – Chyme – Pepsin begins protein breakdown

GI con’d Small Intestine (95% digestion occurs here) – 20’ long when stretched…1” diameter – Duodenum(12”) – Jejunum (4 ‘) – Ileum (5 ‘) Large Intestine (colon) – Little digestion – Water reabsorption – Bacteria work on fiber – Feces pass through rectum and anus

Absorption of Nutrients Passage of nutrients from digestive to circulatory and lymphatic systems Water soluble nutrients – Amino acids, monosaccharides, minerals, vitamin C, B vitamins Fat soluble nutrients – Vitamins A, D, E, K, fatty acids, glycerol, monoglycerides

Metabolism Chemical changes producing energy Energy stored in muscles-adenosine triphosphate (ATP) Waste products from cell metabolism discarded through – Kidneys – Lungs – Skin

Factors Affecting Digestion Eating habits Emotions Food allergies Physical exercise

Digestive Disorders Diarrhea Constipation Indigestion Heartburn (GERD) Ulcer Gallstones Diverticulosis