3. Learning Objectives  I can explain the overall importance of the digestive system in animals.  I know what an enzyme is and what it does during digestion.  I can list the different kinds of nutrients found in food and I know what each is used for in the body.  I can explain how the food pyramid works and/or how to read it.

4. NOTE There are a few differences in text on this PowerPoint slide show (compared to the student notes). These differences are in red italics. You are not expected to write these down on your notes, but listen and ask questions if it doesn’t make sense!

5. Digestion is… o The process of breaking food into small molecules o Absorbing those small molecules/nutrients into the body..

6. Nutrients … Nutrients are substances in food that provide ENERGY and materials for cell development, GROWTH and REPAIR

7. The food pyramid suggests what food groups to eat and the size of the serving (the larger the slice = the bigger the serving you should eat). The new pyramid also emphasizes the importance of getting EXERCISE.

8. Nutrition by Brainpop

9. There are Two Types of Digestion Mechanical digestion : breaking down food using physical force Examples: chewing, mixing and churning.

10. There are Two Types of Digestion Chemical digestion : breaking down food into smaller molecules through chemical reactions. Examples: Enzymes Acids Bile

11. Enzymes o …are molecules that speed up the rate of chemical reactions

12. Enzymes amylase is secreted in the mouth (in saliva). This enzyme breaks down STARCHES. Starches = foods like bread, pasta, potatoes, rice

13. Enzymes PEPSIN is found in the stomach. It breaks complex proteins into less complex proteins protein= foods like meat, eggs, nuts, legumes/beans

14. Enzymes  Enzymes are also responsible for MANY chemical reactions in your body---not just the ones involved in digestion! Amylase only works on STARCHES Pepsin only works on PROTEINS

16. Mouth First place food enters your body Begins chemical & mechanical digestion Different kinds of teeth do different kinds of job. Made of bone.

17. Mouth Which jaw belongs to a carnivore? (meat eater) ________ Which jaw belongs to an herbivore? (plant eater) _______ What kind of teeth do humans have? Touch or examine yours! What kind of eater are we? OMNIVORESOMNIVORES (we eat all kinds of foods)

18. Mouth Glands in the mouth produce saliva which contains amylase, which breaks down starch. SALIVASALIVA = 98% water + amylase + mucus, etc.

19. Mouth TongueTongue : used for chewing, tasting food (with taste buds) and talking

20. CLIPS & ACTIVITIES Teeth by Brainpop In the Mouth—Mechanical & Chemical Digestion ClipIn the Mouth—Mechanical & Chemical Digestion Clip

21. DO NOT CHEW IT, ROLL IT AROUND OR SUCK ON IT.Place one marshmallow in the center of your tongue. DO NOT CHEW IT, ROLL IT AROUND OR SUCK ON IT. Just let the marshmallow sit on the middle of your tongue. Time how long it takes to dissolve in your mouth. Which kind of digestion is this? Which enzyme is at work on this marshmallow? Why is it important that your mouth do both kinds of digestion? Amylase observation

22. Learning Objectives  I can explain the function of each digestive organ in the human body.  I can identify the major parts of the digestive tract from a diagram.  I know what an enzyme is and what it does during digestion.  I understand how my digestive system helps me maintain homeostasis. I know which part(s) of the digestive system help to regulate my body’s internal environment.

23. Esophagus Muscular tube that connects throat to stomach Moves food down by squeezing (peristalsis) Peristalsis (pear-a-stal-sis) : the squeezing of muscles and organs as food moves through the digestive tract

24. Esophagus The epiglottis seals off your windpipe when you swallow so that food doesn’t get into your lungs

25. Other things “back there” What are these things for?? Any ideas?

26. Stomach muscular bag where chemical and mechanical digestion continue

27. Stomach Mechanical digestion occurs through churning/ peristalsis

28. STomach Stomach acid and enzymes (pepsin) perform chemical digestion

29. STomach food stays here ~4 hours; changes to chyme (pronounced kime) Yes, sometimes astronauts throw up!

30. Small Intestine tube nearly 7 meters long where digestive juices from the liver and pancreas are added to chyme It is divided into 3 sections

31. Small Intestine Villi absorb molecules from chyme (increases surface area for absorption Food molecules enter blood stream

32. Small Intestine CHYME = partially broken down food Duodenum = upper part of small intestine where food is still being broken down

33. Pancreas yellowisha small, yellowish organ that produces substances that stop the action of stomach acid makes enzymes that break down carbohydrates food does NOT pass through the pancreas

34. Liver reddishLarge reddish organ that filters the nutrient-rich blood (it is the largest internal organ—has 4 lobes); has many other jobs greenishProduces a greenish substance called bile. Bile breaks up large particles of fat into smaller particles. FOOD DOES NOT PASS THROUGH THE LIVER!

35. Gall bladder small sac that stores bile produced by liver FOOD DOES NOT PASS THROUGH THE GALL BADDER!

36. Large intestine ALSO KNOWN AS COLON absorbs water from undigested food unabsorbed materials become more solid

37. Large intestine shorter but larger diameter tube appendix is offshoot of large intestine homeostasishelps the body maintain fluid balance (homeostasis)

38. Rectum where muscles control the release of waste from the body.

39. ANus opening where solid waste leaves the body

41. mouth Large intestine liver pancreas Gall bladder stomach esophagus Small intestine rectum

42. Digestive System by Brainpop 1) Where does digestion begin? 2) What connects your mouth to your stomach? 3) What is the duodenum? 4) What is one organ that food doesn’t pass through, that is still important in digestion?

43. Body Weight by BrainpopBody Weight Metabolism by BrainpopMetabolism Eating Disorders by BrainpopEating Disorders The Process of Digestion Clip (13 minutes)The Process of Digestion Clip (13 minutes) Related Clips

44. http://www.kitses.com/animation/swf s/digestion.swfhttp://www.kitses.com/animation/swf s/digestion.swf Animations