2. Food & Nutrients

3. Why do we need food? Food eaten Burnt up in respiration to produce energy Storage Growth of new tissue Repair of damaged tissue Movement (Kinetic energy) Warmth (heat energy)

4. The 5 Nutrient groups & 5 Food groups ► ► 1. Carbohydrates ► ► 2. Lipids (fats and oils) ► ► 3. Proteins ► ► 4. Vitamins ► ► 5. Minerals

5. 1. Carbohydrates ► ► Chemical compounds of carbon, hydrogen and oxygen (CH 2 O) ► ► Easiest source of fuel for the body to utilise ► ► Comes from plants in the form of sugars and starches ► ► Starch – from vegetables ► ► Sugars (glucose)– mainly from fruits

6. 1. Simple carbohydrates ► One or two units of sugar linked together to form a chain ► Includes sugars such as glucose and sucrose ► Tastes sweet

7. 1. Complex carbohydrates ► ► Hundreds or thousands of sugar units linked to single molecules ► ► Two groups – high fibre and low fibre ► ► High fibre we can’t digest because cellulose is indigestible ► ► Cows have the necessary enzyme to break it down which is why they can eat grass

8. 1. Carbohydrates Complex carbohydrates can be broken down by the enzyme amylase to simple carbohydrates. Amylase is in our saliva. Amylase Long chain complex carbohydrate Many short chain simples carbohydrates

9. 2. Lipids – fats & oils Fats are solid at room temperature & come from animal tissue Lipids are vital to all animals Part of cell membranes Important in nerve tissue Provide a high amount of energy Oils are liquid at room temperature & come from plants

10. 2. Fat molecules Lipase Glycerol Fatty Acids Fat molecules are made up of fatty acids and glycerol The enzyme used to break them down is called lipase We need to break them down so our bodies can use them Lipase is released in the small intestine

11. 3. Protein ► ► Most foods contain some protein, especially food from animals ► ► Main structural part of body cells (needed for growth and repair) ► ► Make up the main chemicals that control the body

12. 3. Proteins ► ► Made up of lots of amino acids ► ► 20 different amino acids in total ► ► Amino acids contain carbon, hydrogen, oxygen and nitrogen ► ► About half can be made by our bodies alone ► ► 8 Essential amino acids must come from our diet Pepsin

13. 3. Protein deficiency Kwashiorkor

14. 4. Vitamins ► ► Only need in small amounts (compared to Carbohydrates, Proteins and fats) ► ► Some made by body (K & D) ► ► Most need from diet ► ► A lack of any one results in deficiencies ► ► Vitamin A, B1, B2, B3, B6, B12, C, D, E, K ► ► Most are water soluble so therefore our body cannot store them ► ► Some are fat soluble and are therefore stored in our fat

15. 4. Vitamin deficiencies Scurvy – Lack of Vitamin C

16. 4. Vitamin deficiencies Rickets – Lack of Vitamin D

17. 5. Minerals ► ► Needed for growth & general health ► ► Calcium, fluorine, iron, iodine, phosphorus, sodium, potassium, zinc ► ► Many herbivores (eat vegetables only) can’t get enough sodium and chloride from their diet so they will visit natural salt licks – and lick the ground to get enough!

18. The End !