FOOD AND ITS USE BY BODY

1. NUTRIENTS IN FOOD2. 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 term1 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

THE DIGESTIVE SYSTEM

DIGESTIVE TRACT DIGESTIVE 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 TRACT2 – DIGESTION OF FOOD3 – ABSORPTION OF NUTRIENTS4 – ELIMINATION OF FECAL MATTER

THE DIGESTIVE SYSTEMCOMMON 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

SECRETIONS LOCATION TARGETS

SALIVARY GLANDS

Saliva Mouth Starch

GASTRIC GLANDS

Gastric juice Stomach Protein

INTESTINAL GLANDS

Intestinal juice Small intestine Protein, carbohydrates, fats

PANCREAS Pancreatic juice Small intestine Protein, carbohydrates, fats

LIVER Bile Small intestine Fats

DIGESTIVE PROCESS P. 172