FOOD AND ITS USE BY BODY 1. NUTRIENTS IN FOOD 2. THE DIGESTIVE SYSTEM DIGESTIVE SYSTEM – YOUTUBE NUTRITION

NUTRIENTS IN FOOD A NUTRIENT is a substance found in food that is used by the body to meet important needs. 6 TYPES OF NUTRIENTS: - PROTEINS - CARBOHYDRATES - FATS - WATER - VITAMINS - MINERALS Our body must balance the energy we gain from intake food and drink with the energy they expend carrying out our daily activities.

ENERGY REQUIREMENTS JOULES: the measurement unit for energy adopted by the INTERNATIONAL SYSTEM OF UNITS CALORIES: more common term 1 calorie = 4000 joules ACTIVITY – (one hour) - SLEEPING: 240 kj – 60 Cal - WATCHING TV/VIDEO GAMES: 360 kj – 90 Cal - WALKING: 680 kj – 170 Cal - SPORTS: 1200 kj – 300 Cal

NUTRIENTS IN FOOD PROTEINS: large molecules composed of amino acids. Build and repair cells and tissues (muscle) Provide energy Dairy products, meat, fish, nuts, legumes, tofu CARBOHYDRATES: composed of single sugar molecule or chain of sugar molecules. Bodies main source of energy Monosaccharides & Disaccharides: fruits, juices, pastries, sweets Polysaccharides (starch): breads, cereals, pasta, potatoes, rice FATS: lipids composed of fatty acids and glycerol (cholesterol). Store and provide energy, Building blocks of hormonal and cell membranes Protects organs and insulates the body from the cold Dairy products, butter, meats, fish, french fries, eggs

NUTRIENTS IN FOOD WATER: a simple molecule H2O. 70% of our body weight. Transports nutrients and water products Regulates body temperature Essential in numerous chemical reactions in body Fruits, juices, vegetables, soups, milk, energy drinks VITAMINS: substances that the human body requires in small amounts Every vitamin contributes differently / chemical reactions Helping energy production Help fights off infection Repair damaged tissue Fruits, vegetables, dairy, whole grains, eggs, liver MINERALS: mineral origin, we need a certain amount ingested daily. Calcium, phosphorous, iron, potassium, zinc Building tissue (teeth, bones) Fluid balance, muscle contraction, oxygen transportation Dairy, seafood, fruits, vegetables

4 FOOD GROUPS VEGETABLES & FRUITS (7 f – 8 m) GRAINS (6 f – 7 m) DAIRY PRODUCTS ( ¾ f – m) MEATS & ALTERNATIVES ( 2 f – 3 m)

THE DIGESTIVE SYSTEM The cells of the human organism cannot use most food directly for energy. It must be transformed in the digestive system before the organism can put it to use. The digestive system’s role is to break down ingested food into molecules that are small enough to be absorbed. It also eliminates undigested food from the body in the form of solid waste. The digestive system can be divided into 2 parts: - the digestive tract - the digestive glands Digestive System – YouTube

THE DIGESTIVE SYSTEM

DIGESTIVE TRACTDIGESTIVE GLANDS -MOUTH - PHARYNX - ESOPHAGUS -STOMACH - SMALL INTESTINE - LARGE INTESTINE - RECTUM / ANUS -SALIVARY GLANDS - GASTRIC GLANDS - LIVER - PANCREAS - INTESTINAL GLANDS (lining of small intestine) DIGESTION OF FOOD IS A COMPLICATED PROCESS THAT INVOLVES THE FOLLOWING FUNCTIONS: 1 – INGESTION AND PROPULSION OF FOOD ALONG THE DIGESTIVE TRACT 2 – DIGESTION OF FOOD 3 – ABSORPTION OF NUTRIENTS 4 – ELIMINATION OF FECAL MATTER

THE DIGESTIVE SYSTEM COMMON TERMS: DEGLUTITION – the act of swallowing PERISTALSIS – muscular contractions of the esophagus, stomach, and intestines that propel substances through the digestive tract DIGESTION – involves the transformation of food into nutrients that can be used by the body MECHANICAL TRANSFORMATION – consists of physically breaking down food into smaller substances in preparation for chemical transformation (chewing, churning) CHEMICAL TRANSFORMATION – in the digestive tract breaks down the complex molecules of food into simpler molecules. These changes occur with the help of secretions from the digestive glands NUTRIENTS – foods that can be absorbed by the body ABSORPTION – the passage of nutrients from the digestive tract into the blood or lymph

DIGESTIVE GLANDS AND SECRETIONS DIGESTIVE GLAND SECRETIONSLOCATIONTARGETS SALIVARY GLANDS SalivaMouthStarch GASTRIC GLANDS Gastric juiceStomachProtein INTESTINAL GLANDS Intestinal juiceSmall intestineProtein, carbohydrates, fats PANCREASPancreatic juiceSmall intestineProtein, carbohydrates, fats LIVERBileSmall intestineFats

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