2. NUTRITION A life function When organisms take in & use nutrients needed for energy & all life processes

3. Nutrients Substances in foods that provide energy & materials for life processes

4. 6 nutrients needed by the body

5. 1.Carbohydrates Main source of energy

6. Simple carbohydrates a.k.a. sugars Found in Fruits, honey, milk

7. Complex carbohydrates a.k.a. starches & fiber Found in Bread, pasta, potatoes

8. 2. Proteins Replace & repair body cells Growth Made of amino acids

9. Found in eggs, meat, cheese, milk

10. 3. LipidsFats Provide energy (storage) Cushion & support organs

11. 4. Minerals Use 14 of them Maintain normal functioning of the body Calcium, phosphorus, iodine…

12. 5. Vitamins Maintain normal functioning of the body

13. 6. Water Needed for cells to carry out some chemical reactions

14. Calorie Measures the amount of energy in foods

15. How is energy measured in food? Calories Amount of heat needed to raise 1 kg of water 1°C

16. TYPES OF NUTRITION 1. Autotrophic Nutrition Organisms make their own food through the process of photosynthesis Examples: Plants, Algae

17. 2. Heterotrophic Nutrition Organisms must ingest materials already made in the environment Cannot make their own food

18. 4 processes involved in Heterotrophic nutrition: 1.Ingestion: process of taking IN food

19. 2.Digestion: breakdown of food 4.Egestion: removal of undigested food 3. Absorption: Process of nutrients being taken into the bloodstream

20. 1. List the six types Nutrients needed by the body 2. List the four processes involved in Heterotrophic Nutrition

21. 6 nutrients needed by the body

22. Types of Digestion 1. Mechanical Digestion Large pieces of food are broken down into smaller pieces by the teeth

23. Increases surface area of food to speed up chemical digestion Makes food easier to swallow

24. When small food particles are broken down into small molecules called nutrients HOW? Enzymes 2. Chemical Digestion

25. Ex: Starches broken down into Sugar

26. Proteins are broken down into amino acids Called protease

27. 1. Chemical digestion is aided by enzymes. 2. Our food only gets broken down by mechanical digestion. 3.Proteins are used for long term energy storage. 4.Another name for lipids are fats. 5.Enzymes are chemical in the body used to give humans fresh air.

28. Digestive System also known as the Alimentary canal

29. The system is a one way tube The system is made of ________ ________ Smooth muscle

30. Function of the digestive system To breakdown food into nutrients small enough to pass into cells

32. 1.What are enzymes and how do they assist in the digestive process? 2.How does the digestive system assist an organism in maintaining homeostasis? *Adaptation – any special feature that enables an organism to survive in a particular environment

33. Pathway of Food Through The Digestive System

34. The oral cavity is responsible for mechanical digestion by the teeth 1. Oral Cavity (mouth)

36. Did you know… -Your teeth started growing 3 months before you were even born. -The hardest substance in your body is the enamel on your teeth. -As you are sitting there listening, more than 100 million germs are swimming, feeding, reproducing, and making waste in the area behind your lips. In your mouth there are more living things than there are people in Australia and Canada combined…

37. Contains Saliva from salivary glands Saliva is responsible for the chemical digestion of certain foods

38. Chemical digestion of carbohydrates by saliva Enzyme in saliva is called Amylase Digests starch into sugar

39. 2. Epiglottis Small flap of tissue Closes over windpipe when you swallow To prevent choking

42. 3. Esophagus Connects mouth to stomach NO DIGESTION OCCURS IN THE ESOPHAGUS

43. Carries out Peristalsis: muscular movement that pushes food through digestive tract

46. 1. Explain the difference between chemical and mechanical digestion. 2. Where does digestion begin? 3. What structures in the digestive system produce saliva? HW: Handout “digestive system”

47. 4. Stomach J-shaped muscular organ Contains Gastric glands in wall that secrete/release gastric juice

48. Gastric juice Contains enzymes that chemically digest food

49. Gastric Juice contains: 1. Hydrochloric acid

50. 2. Enzyme: Pepsin Chemically digests protein into amino acids

51. The stomach has a Mucus lining that coats the stomach for protection

52. The stomach is also responsible for Mechanical digestion by churning and mixing food

53. 5. Small intestine Average length is 21 feet (4-7 meters)

54. Most chemical digestion occurs there Chemical digestion ends here ABSORPTION OCCURS HERE

55. The small intestine contains Intestinal juice that is released from liver and pancreas Contains enzymes

56. 6. Large Intestine NO DIGESTION Reabsorbs water Forms feces (undigested food) Contains bacteria

57. Appendix attached the lower portion of the large intestine No function

58. If you squeezed out all of the bacteria that lives in your intestines, you could almost fill up a coffee mug.

60. Rectum Last part of large intestine Stores feces

61. Where feces is egested out of the body Anus