6. Teeth Structures - hard like bone but softer than enamel ,living tissue, thread of cytoplasm are running through it. It is hardened by vitamin D external structure internal structure dentine crown neck root
7. Teeth Structures - supply food & oxygen for growth & maintaining alive - produce sensation of pain when stimulated external structure internal structure crown neck root blood capillaries nerve fibres pulp cavity ( living tissues )
8. Teeth Structures made up of connective tissues which make up your dentine and keep tooth alive. external structure internal structure crown neck root blood capillaries nerve fibres pulp cavity ( living tissues )
17. What do you find on the covered and uncovered parts of the tooth ? Ans: The acid dissolves the exposed enamel and leaves a small hole on the uncovered part, but holes do not appear on the covered part. tooth covered with wax dilute hydrochloric acid probing scraping
18. Does the acid take place in causing tooth decay ? Ans: Actually the acid produced by bacteria in the mouth is not very strong. Tooth decay is due to bad habits over a long period of time. tooth covered with wax dilute hydrochloric acid probing scraping
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25. A process by which large food molecules are broken down into smaller pieces Digestion
27. Because: food pieces and their molecules (e.g. starch, protein & fat) are usually too large to pass through the wall of our body for absorption (Note: Simple sugars, water, vitamins & minerals are small enough to be absorbed immediately.)
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29. Human Digestive System salivary glands epiglottis oesophagus diaphragm cardiac sphincter stomach spleen pyloric sphincter colon caecum rectum anus large intestine pancreas buccal cavity tongue tooth trachea liver duodenum ileum appendix small intestine gall bladder
30. Mechanical Digestion Chewing : break down food into smaller pieces by teeth to increase the surface area for enzyme action ( physical digestion )
32. Investigation 7.2 To show the Differential Permeability of Dialysis Tubing to Starch & Glucose
33. Why is it necessary to rinse the dialysis tubing with tap water ? Ans: In order to remove any starch and glucose that may remain on the outside of the dialysis tubing. Starch-glucose mixture thread Test for glucose Test for starch
34. Which food substance is present in water surrounding the dialysis tubing 30 minutes after the beginning of the experiment ? Explain your answer. Ans: Glucose. As dialysis tubing is selectively permeable, starch molecules are too large to pass through the holes in the tubing... Starch-glucose mixture thread Test for glucose Test for starch
35. Which food substance is present in water surrounding the dialysis tubing 30 minutes after the beginning of the experiment ? Explain your answer. Ans: Only glucose molecules are small enough to pass through the dialysis tubing in this experiment. Starch-glucose mixture thread Test for glucose Test for starch
36. Which part of the body is presented by the dialysis tubing and the water in the boiling tube respectively ? Ans: Ileum and blood are represented by the dialysis tubing and water respectively. Starch-glucose mixture thread Test for glucose Test for starch
42. What are the results of the iodine test and Benedict’s test for tube A ? Ans: The result of iodine test is negative while the result of the Benedict’s test is positive. A B C thermometer water bath at 37 ℃ after 30 minutes each test tube test with Benedict’s solution test sample with iodine solution
43. What are the results of the iodine test and Benedict’s test for tube B ? Ans: The result of iodine test is positive while the result of the Benedict’s test is negative. A B C thermometer water bath at 37 ℃ after 30 minutes each test tube test with Benedict’s solution test sample with iodine solution
44. What are the results of the iodine test and Benedict’s test for tube C ? Ans: The result of iodine test is positive while the result of the Benedict’s test is negative. A B C thermometer water bath at 37 ℃ after 30 minutes each test tube test with Benedict’s solution test sample with iodine solution
45. Why is the temperature of the water bath set at 37 ℃ ? Ans: Because enzymes work best at 37 ℃ . A B C thermometer water bath at 37 ℃ after 30 minutes each test tube test with Benedict’s solution test sample with iodine solution
46. What is the action of amylase on starch ? Ans: Amylase is an enzyme in saliva which helps to digest starch into maltose. A B C thermometer water bath at 37 ℃ after 30 minutes each test tube test with Benedict’s solution test sample with iodine solution
47. What is the effect of boiling on amylase ? Ans: Amylase denatured after boiling. A B C thermometer water bath at 37 ℃ after 30 minutes each test tube test with Benedict’s solution test sample with iodine solution
48. Chemical Digestion break down of starch molecules into maltose molecules by salivary amylase (from salivary glands) Starch maltoses salivary glands
49. Stomach (Physical Digestion) Stomach Entrance: Cardiac Sphincter Stomach Exit: Pyloric Sphincter Relaxation of cardiac sphincter & contraction of pyloric sphincter enable storage of food in stomach for a longer period of time
50. Stomach (Physical Digestion) Squeezing & churning actions of stomach break down the partly digested food into smaller pieces which forms a semi-fluid called Chyme
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53. Small Intestine (mainly chemical digestion) Digestion of various food substances by several kinds of digestive juices Digestive juices found in small intestine: 1. Bile 2. Pancreatic juice 3. Intestinal juice
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56. Bile - contain bile salts which emulsify lipids into smaller droplets without chemical change ( ∴ NOT digest fats) - provide alkaline medium for enzymes to work oil oil droplets
58. What happens to the mixtures in tubes A & B ? Ans: In tube A, bile salt emulsifies the vegetable oil to droplets. In tube B, the oil floats on top of water since oil and water do not mix well. 1cm 3 of vegetative oil shaking shaking observe observe 10 drops of bile salt solution A B
59. What is the action of bile salt on oil ? Ans: The bile salt reduces the surface tension of oil and emulsifies oil to droplets. 1cm 3 of vegetative oil shaking shaking observe observe 10 drops of bile salt solution A B
