Objectives 30.2 Nutrition - Explain how food provides energy. - Identify the essential nutrients your body needs and tell how each is important to the body. - Explain how to plan a balanced diet.

Vocabulary Word Definition Calorie Measure of heat energy in food: equivalent to 1000 calories Carbohydrate Compound made of C, H, O atoms, major source of energy fat Lipid, made of fatty acids and glycerol: nutrient protects body organs, stores energy Protein Macromolecule that contains C, H, O, N: needed for growth, repair , homeostasis, and metabolism Vitamin Organic molecule that helps regulate body processes, important for homeostasis Mineral Inorganic nutrient body needs, usually small amounts

Energy The energy stored in food molecules is released during cellular respiration and used to produce the ATP molecules that power cellular activities. The unit used to measure the amount of energy stored in food is a calorie.   A calorie is the amount of heat needed to raise the temperature of 1 gram of water by 1 degree Celsius.

Each cell gets energy (ATP) from the nutrients (preferably carbohydrates) they eat in food (cellular respiration), to cash in the energy a phosphate is removed.

Nutrients Nutrients are substances in food that supply the energy and raw materials your body uses for growth, repair, and maintenance. These molecules are made up of C,H,O,N,P,S Remember macromolecules from chp 2.3  

Water The most important nutrient is water. Many of the body’s processes, including chemical reactions, take place in water. Remember: pH, solutions from chp 2.2  

Carbohydrates Simple and complex carbohydrates are a major source of energy for the body. The sugars found in fruits, honey, and sugar cane are simple carbohydrates, or monosaccharides and disaccharides. The starches found in grains, potatoes, and vegetables are complex carbohydrates, or polysaccharides.

Fats Fats, or lipids, are an important part of a healthy diet when consumed in moderation.   Fats help the body absorb fat-soluble vitamins and are part of cell membranes, parts of nerve cells and certain hormones. Deposits of fat protect body organs and insulate the body.

Fats If each carbon atom in a lipid’s fatty acid chains is joined to another carbon atom by a single bond, the lipid is said to be saturated. Lipids that contain saturated fatty acids are solid at room temperature. If double or triple bonds are present, creating what appears to be kinks in the chain, the lipid is said to be unsaturated. Lipids that contain unsaturated fatty acids, such as olive oil, tend to be liquid at room temperature.

Proteins Proteins supply raw materials for growth and repair of structures such as skin and muscle. Made up of amino acids   Many enzymes are made of proteins. Proteins also have regulatory and transport functions.

Vitamins Organic molecules that the body needs in very small amounts are called vitamins. Most vitamins are needed by the body to help perform important chemical reactions.   Most vitamins must be obtained from food. However, the bacteria that live in the large intestine can synthesize vitamin K and vitamin B12.

Vitamins There are two types of vitamins: fat-soluble and water-soluble.   The fat-soluble vitamins A, D, E, and K can be stored in the fatty tissues of the body. The body can build up small deposits of these vitamins for future use. The water-soluble vitamins, which include vitamin C and the B vitamins, dissolve in water and cannot be stored in the body.

Minerals Inorganic nutrients that the body needs, usually in small amounts, are called minerals.   A constant supply of minerals in the diet is needed to replace those lost in sweat, urine, and digestive wastes.