2. What parts of the mouth contribute to the formation of the bolus? What role does each mouth part contribute?

BIOLOGY 12: CHAPTER 12 - REVIEW WORKSHEET DIGESTIVE SYSTEM A. CHAPTER REVIEW 1. List and explain the four functional stages of digestion. ____________...
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BIOLOGY 12: CHAPTER 12 - REVIEW WORKSHEET DIGESTIVE SYSTEM A. CHAPTER REVIEW 1. List and explain the four functional stages of digestion. _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 2. What parts of the mouth contribute to the formation of the bolus? What role does each mouth part contribute? _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 3. What prevents food from entering the nasal chamber (nasopharynx) and the trachea during swallowing of food? _____________________________________________________________________________________________________________________ 4. What enzymatic reaction occurs in the mouth? _____________________________________________________________________________________________________________________ 5. The opening to the larynx is called the ____________, which is covered when the trachea moves up under the ____________________. 6. a) List the four layers of the digestive tract and explain the functions of each. _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ b) Label the layers in the diagram.

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7. What causes the food to be pushed along in the esophagus? _____________________________________________________________________________________________________________________ 8. What is responsible for heartburn and how is it normally prevented? _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 9. List the functions of the stomach. What is chyme? _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 10. What is an ulcer and why does it form? _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 11. Write the chemical reaction that occurs in the stomach. _____________________________________________________________________________________________________________________ 12. List the functions of the small intestine. What molecule from the pancreas neutralizes the acidity of chime? _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 13. What five reactions take place in the duodenum? _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 14. Describe the structure of villi and microvilli in the small intestine. _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 15. What three enzymatic reactions take place in the small intestine? _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 16. How are the small nutrient monomers absorbed across the wall of each villus? What do they enter? _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 17. What is the function of the large intestine? How does its size compare with the small intestine? _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 18. a) Which associate organ of the large intestine plays a role in immunity? ____________________ b) What is the term used to refer to the inflammation of this organ? _______________________ c) What is the term used to refer to surgical removal of this organ? ________________________ 19. Over 99% of bacteria in the colon are classified as ______________________, because they die in the presence of oxygen. 20. Describe the effects of bacteria in the large intestine. What does a HIGH coliform count in lake water mean? _____________________________________________________________________________________________________________________ 21. How do food poisoning and nerve stimulation cause diarrhea? Why is this dangerous to a person’s health? _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 22. How does mineral oil work to overcome constipation? _____________________________________________________________________________________________________________________

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23. What is the exocrine function of the pancreas? Name the transport vessel of pancreatic secretions. _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 24. What is the endocrine function of the pancreas? How do these feedback cycles work? _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 25. What are the components of bile? Where is bile produced? Where is it stored? _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 26. Explain why the liver is said to act as the gatekeeper of the blood. _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 27. Define deamination. What happens to the amino groups in the liver? How is it excreted? _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ Write out the reaction of urea production. _____________________________________________________________________________________________________________________ 28. Explain ALL the functions of the liver. _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 29. Read p. 223. Distinguish between haemolytic jaundice and obstructive jaundice. _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 30. What are the causes of the various forms of viral hepatitis? _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 31. What is lactose intolerance due to? What are the consequences of drinking milk in these individuals? (refer to p. 224) _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 32. Define a nutrient. How is a balanced diet achieved? _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 33. Define an essential amino acid. Distinguish between a complete and incomplete protein source. _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 34. Why are simple carbohydrates sometimes referred to as “empty calories?” (p. 227) _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 35. What are the advantages of both insoluble and soluble fibre in our diets? (p. 227) _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________

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36. List four ways to reduce dietary fat. _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 37. Distinguish between the functions of low-density lipoproteins and high-density lipoproteins. _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 38. What are vitamins? Give their function. _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 39. How do free radicals harm the body? (p. 230) _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ 40. How does the body defend itself against free radicals? _____________________________________________________________________________________________________________________ 41. Read p. 232. What is the cause of osteoporosis? What three things can women do to reduce the risk of developing osteoporosis? _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________ B. COMPLETION AND SHORT ANSWER QUESTIONS 1. The stomach is directly connected to the __________________ above and the ___________ ___________________ (2 words) below. 2. The major food molecule digested in the stomach is ___________, which is hydrolyzed by the enzyme _____________. The enzyme’s inactive form is called _________________. 3. Among its chemical aspects, every digestive enzyme has a preferred _____. 4. Before fats are digested by the enzyme _________________, they are first emulsified by _______________. 5. Pancreatic juices enter the small intestine (duodenum) by way of the ____________ duct and contain _____________ for the digestion of EVERY type of food. 6. The liver first receives the products of digestion by means of the ______________ _____________ vein; any excess glucose is stored as ____________________. 7. The secretion of digestive juices is controlled generally by both _________________ and _________________. 8. Surface area in the small intestine is increased greatly by the presence of _______________ and _________________. 9. There are _____________ essential amino acids required by adults. 10. There are ________ essential fatty acids required by adults. 11. Complete the following table. HORMONE

PRODUCTION SITE

TRIGGER/CAUSE OF RELEASE

AFFECTED ORGAN(S)

ACTION OF AFFECTED ORGAN

GASTRIN GASTRIC INHIBITORY PEPTIDE (GIP) SECRETIN CHOLECYSTOLKININ (CCK)

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12. Vitamins are portions of _________________, which are necessary for cellular metabolism. 13. Answer the following questions about the digestive tract. a) In which part of the digestive tract are nutrient molecules absorbed? ____________________________ b) The absorbed nutrient molecules enter what vein associated with the liver and intestine? __________________________________________________________________________________________________________________ c) In which specific part of the digestive tract does pancreatic juice enter?_____________________ d) In which specific part of the digestive tract does bile enter? __________________________ e) The three accessory organs that do NOT contain food are the ______________, _____________________, and _________________. f) What parts of the digestive tract do NOT have ducts entering them and do NOT secrete digestive juices? __________________________________________________________________________________________________________________ 14. Carbohydrate Digestion (starch) Starch digestion begins in the ___________, Here, the ducts empty saliva from the _____________ glands. There are three pairs of these glands, named parotid glands, sublingual glands, and submandibular glands. The saliva from these glands contains the enzyme _______________ ______________, and this enzyme breaks down starch to the disaccharide ______________. Starch will continue to be broken down in the __________ _______________. Here, a duct empties from the ________________. Pancreatic juice contains the enzyme _______________, which breaks down starch to the disaccharide ________________.

Starch digestion is completed when this disaccharide is broken down to _______________, a

monosaccharide that can be absorbed by intestinal ____________. The enzyme that converts maltose to glucose is called _____________, and this enzyme is secreted by epithelial cells of the intestinal villus. 15. Protein Digestion (meat) Protein digestion begins in the _____________. The _____________ glands line the wall of the stomach. They secrete the enzyme ____________________, which is converted into its active form ________________ by hydrochloric acid; this enzyme breaks down protein into ______________. In the _______________ (gland), another enzyme called _____________ acts on protein in the ___________ _________________, breaking down protein into ____________. Protein digestion is completed when peptides are broken down to ________ ____________, molecules small enough to be absorbed by intestinal villi. This is achieved by the enzyme ___________________, which is produced by the epithelial cells of the intestinal villus. 16. Fat Digestion (butter) Fat is first emulsified by ______________, a substance made by the liver and stored in the _________________ (gland). The secretions in this gland enter the small intestine by way of the _____________ duct. After the fat has been emulsified, it is broken down by the enzyme _____________, which is found in pancreatic juice. Fats are broken down to ______________ and fatty acids, molecules small enough to be absorbed by intestinal villi. After resynthesis (~repackage) into ________________, fats enter the _______________, which are part of the lymphatic system. 17. Path of Food. a) Food consists of the large organic molecules ________________, ____________________, and __________. In the mouth, the only type of food digested are ______________________. The mouth has a neutral ________ of ____________. The food passes down the long tube called the _________________. A rhythmic contraction called ________________ pushes the food along.

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b) After passing through a sphincter (circular muscle), the food enters the _____________. Here the primary food acted on is ________________. This organ has a(n) ____________ pH of _____. The food is now called _____________, which passes through another sphincter into the______________, which is the first section of the ________ ________________. c) Two ducts enter this organ; they are the _____________ ____________ ___________ from the ______________________ and the _____________ ___________ from the ________________. Bile contains an emulsifier that divides fat into fat droplets. Pancreatic juice contains enzymes that act on _______________, _____________, ___________ and _____________ _________. Lining the walls of the intestine are ___________ with _________________ on the apical surface of each cell. The epithelial cells produce enzymes that finish digestion by converting ____________ to glucose and _____________ to amino acids. Thus the small nutrient molecules that are absorbed by villi are ___________ __________ and ____________, which enter the ___________ portal vein. ____________ and ___________ ___________ enter the _____________. d) The ___________ portal vein takes the nutrients to the ___________, an organ of homeostasis. For example, this organ stores glucose as _____________, and always keeps the blood glucose level constant. This organ can also remove amino groups from __________ __________ and convert the amino groups to ____________, a nitrogenous waste product.

18. What happens to a person who takes in more calories/energy than needed? _____________________________________________________________________________________________________________________ C. DIGESTIVE ENZYME ACTIVITY For each combination of substances below, decide whether digestion will or won’t occur. If it does not, provide a reason why. (Hint: remember to consider optimum pH of the enzyme) 1. trypsin, NaHCO3, egg white - warm gently _____________________________________________________________________________________________________________________ 2. salivary amylase, water, egg white – warm gently _____________________________________________________________________________________________________________________ 3. pepsin, HCl, egg white – freeze _____________________________________________________________________________________________________________________ 4. pancreatic amylase, HCl, starch – heat to boiling _____________________________________________________________________________________________________________________ 5. lipase, NaHCO3, fats – warm gently _____________________________________________________________________________________________________________________ 6. maltase, HCl, maltose – warm gently _____________________________________________________________________________________________________________________ 7. peptidases, fat, HCl – warm gently _____________________________________________________________________________________________________________________ 8. pepsin, HCl, egg white – warm gently _____________________________________________________________________________________________________________________ 9. trypsin, starch, water – warm gently _____________________________________________________________________________________________________________________ 10. HCl, egg white, water, warm gently _____________________________________________________________________________________________________________________

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