Why do we need food? Provides energy Provides the body with materials for growth and repair

Nutrients Nutrients = parts of food that your body can use The 6 Nutrients 1.Protein 2.Carbohydrates 3.Fats and Oils 4.Vitamins 5.Minerals 6.Water

1. Proteins Structure – Made of amino acids Function – Used to build and repair body parts Examples of Proteins – Complete Proteins: meat, fish, eggs – Incomplete proteins: beans, grains, nuts, rice veggies, cereal

Proteins There are 20 amino acids that make up thousands of proteins Your body can make about half of the amino acids it needs The other half come from the food you eat. These are called essential amino acids Complete Proteins = foods that contain all the essential amino acids Incomplete Proteins = foods missing a few of the essential amino acids

2. Carbohydrates Structure – Made of sugar and starches Function – Supply body with main source of energy Examples of Carbohydrates – Simple Carbohydrates = fruit, brownies, cookies, whole milk – Complex Carbohydrates = pasta, bread, corn

Carbohydrates Simple Carbohydrates = sugars Complex Carbohydrates = many sugar molecules linked together Sugar is used as fuel faster than starch in the body… too much turns to fat

3. Fats and Oils Structure – Made up of fatty acids and glycerol Function – Source of energy – Insulates body – Protects organs Examples of Fats and Oils – Saturated Fats = butter, cheese, nuts – Unsaturated Fats = cooking oils

Fats and Oils Unsaturated Fats = liquid at room temperature Saturated Fats = solid at room temperature – Saturated fats create cholesterol  heart disease/heart attack Trans Fats = makes food stay fresh longer – Margarine, chips

4. Vitamins Functions – Regulate Growth Examples of Vitamins – Fat Soluble (dissolve in fat) = A, D, E, K – Water soluble (dissolve in water) = C and all B vitamins

Vitamin Deficiency Causes many health problems Examples – Scurvy = lack of vitamin C Symptoms: bleeding gums, stiff joints, and sores that do not heal – Rickets = lack of vitamin D Symptoms: softening of bones in children, fractures, deformation – BeriBeri = lack of vitamin B 1 Symptoms: weight loss, weakness, and pain in the limbs

5. Minerals Structure – Nutrients not made by living things Function – Regulate body functions Examples of Minerals – Iron – red blood cell function – Phosphorous- healthy bones – Potassium- water balance, nerve/muscle function

6. Water 65% of a person’s weight is water Structure – H 2 O – hydrogen and oxygen Function – Dissolve all substances – Carried throughout the body Water in your diet – You need 2 liters/day – Fruits and veggies like watermelon and tomatoes

What is a calorie? Calorie = the amount of heat energy needed to raise the temperature of 1 kg of water by 1 degree Celsius. The more calories a food has, the more energy it contains. The more active you are, the greater your energy needs are.

FUN FACT: An average sized person eats about 33 tons of food in his or her lifetime- which is about the weight of 6 elephants The Digestive System

Digestion The process by which your body breaks down the food you eat into substances that it can absorb and use – The digestive system may also be referred to as the Gastrointestinal Tract, Alimentary Canal, and Digestive Tract

Types of Digestion Mechanical Digestion – Foods are physically broken down into smaller pieces – Increases the surface area Ex. Chewing Chemical Digestion – Chemicals produced by the body break foods into their smaller chemical building blocks

Organs of the Digestive System Mouth Esophagus Stomach Small Intestine Large Intestine Rectum Anus

Trick to Remember Organs M= MouthL= Large E= EsophagusI= Intestine S= StomachR= Rectum S= SmallA= Anus I= Intestine

Accessory Organs Organs that help with the functioning of the digestive system Food does not pass through these organs There are four accessory organs – Salivary Glands – Pancreas – Liver – Gallbladder

Digestive System Pathway

Mouth Both Mechanical and Chemical Digestion Begins in the mouth Breaks down starches (carbohydrates)

Mouth Cont. Mechanical= tear food into smaller pieces to increase surface area Chemical= saliva (an enzyme) produced from the salivary glands begins to break down starch

Mouth Continued Bolus= food mass packed together by mucus so that it can easily be swallowed

Esophagus Tube that connects the mouth to the stomach Peristalsis- wavelike motion of muscles that pushes food to the stomach Epiglottis- connective tissue that covers the windpipe (trachea) as food moves past larynx to your esophagus

Stomach Breaks down amino acids (PROTEINS) J shaped Gastric juices (pepsin, hydrochloric acid, and mucus) Chyme- thick soupy digested food

Small Intestine Most digestion and absorption occurs here Completes digestion of starches and proteins Begins digestion of fats

Small Intestine cont. Villi- fingerlike projections that line the small intestine – Digested food is absorbed by the villi into the blood vessels that will carry the nutrients to the body cell – Villi increase surface area for absorption

Liver Aids in digestion in the small intestine Produces bile which is released in the small intestine Bile (green)- breaks down fats

Pancreas Aids in digestion in the small intestine Produces pancreatic juices that are released into the small intestine and break down proteins, starches, and fats Secretes Insulin (regulates blood sugar levels)

Gallbladder Stores excess Bile

Large Intestine No digestion takes place in the large intestine! All undigested food, water, mucus, bile and salts are stored here

Large Intestine cont. The large intestine removes excess water from undigested food. – Water is absorbed into the bloodstream Feces= all solid waste not absorbed by the body

Rectum Stores Waste

Anus Removes waste