DIGESTION MECHANICAL physical breakdown into smaller pieces CHEMICAL

DIGESTION • MECHANICAL: physical breakdown into smaller pieces • CHEMICAL: food is chemically changed; EX: proteins digested into amino acids ALIMENTARY CANAL: Digestive tube extending from Mouth to anus (9 meters !) Muscular tube; part of VENTRAL cavity

Quick overview of digestion: Take out a sheet of paper and answer the following • • • Name two types of digestion List the 4 membrane layers of the digestive tract Movement through the digestive system is controlled by. Name the sphincter between the stomach and the duodenum Which teeth suggests that humans are carnivores? Name 3 sets of tonsils Where are the following digested? A. Proteins B. starch C. Fats D. Sugars What % of each of the following do you need in your diet each day? A. Proteins B. Carbohydrates C. Fats Name the 6 main nutrients your body needs Name 2 groups of vitamins and examples of each. Complete ‘human digestive system’ for review Look over your vocabulary to see if you have questions about any terms

NUTRITION

SIX MAIN NUTRIENTS • • • Carbohydrates Lipids Proteins Vitamins Minerals water

SOURCES OF CARBOHYDRATES • • • Starches Grains Vegetables Sugars fruit

WHY IS CELLULOSE IMPORTANT? To push food through the digestive system (fiber)

FORM OF ENERGY FROM CARBOHYDRATES: GLUCOSE

WHAT HAPPENS TO EXCESS GLUCOSE IN THE BODY? Stored as glycogen in the liver What the liver can’t store gets turned into FAT!

FAT SOURCES provide 2 X+ the energy you get from carb’s & proteins! • SATURATED FATS: meat, eggs, milk, lard, palm/coconut oils • UNSATURATED FATS: seeds, nuts, plant oils (corn, peanut, olive) • CHOLESTEROL: liver, egg yolk, meat, cheeses, butter, milk (not in plant sources)

FUNCTIONS OF CHOLESTEROL • Structural material for cell membranes • Component in sex & adrenal hormones • Excess can build up in arteries and hinder the flow of blood artheriosclerosis

SOURCES OF PROTEINS • • • Meat Fish Poultry Nuts Legumes cheese

ESSENTIAL AMINO ACIDS • There are 20 different amino acids • The body makes some amino acids • Others (essential) must be obtained from certain foods

RECOMMENDED DAILY ALLOWANCE • Carbohydrates: 60% • Lipids: 30% • Proteins: 10%

VITAMINS VS. MINERALS • VITAMINS • Organic (made by living things) • EX: A, B 12, D • MINERALS • Inorganic (naturally occurring) • EX: zinc, phosphorus, iron

VITAMINS FAT-SOLUBLE: A, D, E, K Bile salts important to help promote absorption of these vitamins WATER-SOLUBLE: B&C B VITAMINS: normal cell metabolism; help in digestion of carbs, lipids, proteins C VITAMINS: metabolism of amino acids; iron absorption; synthesis of hormones; production of collagen

MINERALS • Make up 4% Body weight • Most concentrated in bones, teeth • Can be found incorporated in organic molecules or can be free • Comprise structural components of the body • Important in maintaining p. H, osmotic pressure, nerve conduction, muscle contraction, blood clotting

COMMON MINERALS • 2 most common: Calcium & phosphorus • Trace elements: Manganese Iron Zinc Copper Cobalt Fluorine iodine

ADEQUATE DIET • Provides sufficient energy to maintain optimal growth & tissue repair • Provides essential fatty acids, amino acids, vitamins & minerals • MALNUTRITION: Diet that lacks nutrients (lack of food, poor quality food, over-eating, too many vitamin supplements)

NUTRIENT REQUIREMENTS: • • Age Growth rate Stress Environment Sex Physical activity genetics

FOOD PYRAMID