Drew's+digestive+system+review+hw

Digestive System Review 1. Argue that absorption is the most important of the five processes of digestion over the other four processes. (144-45) Absorption is the most important part of the digestive process because this is where the unit molecules produced by digestion cross the wall of the GI tract and enter the cells lining the tract. The nutrients are then delivered to the blood.

2. List the main organs of the digestive tract and state the contribution of each to the digestive process. (146-54) The mouth-the first step in digestion. Here the food begins the chemical and mechanical digestion. The pharynx and esophagus-The food passage and the air passage cross in the pharynx. The esophagus is a long narrow tube that takes food to the stomach The stomach-a thick walled organ that stores food and initiates the digestion of protein. Small intestine-it contains enzymes to digest all foods.

3. Name the enzymes involved in the digestion of starch, protein, and fat, and tell where these enzymes are active and what they do. (151) Carbs: Salivary amylase-mouth Pancreatic amylase-small intestine Maltase-small intestine Protein: Pepsin-stomach Trypsin-small intestine Peptidases-small intestine Nucleic Acid: Nuclease-small intestine Nucleosidases-small intestine Fat: Lipase-small intestine

4. Why are the pancreas, liver, and gall bladder considered accessory organs of digestion and not an organ of digestion? (152) They do not have any enzymes for digestion

5. What is the chief contribution of each of these in the body--carbohydrates, proteins, and lipids (fats)? (158-59) Carbohydrates: used by the body as an energy source Proteins: Protein is used for cell growth Lipids: Some lipids are nutritionally essential because the body cannot make them

Do the multiple choice on page 167-68. Just write the number and your answer.
 * 1) 9 to 29.

9. d 10.b 11.c 12.e 13.c 14.b 15.e 16.c 17.d 18.d 19.d 20.c 21.c 22.e 23.b 24.c 25.d 26.a 27.b 28.c 29.e