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4. DIGESTIVE SYSTEM, Name the following:, End product of starch after digestion: Glucose, i), ii), , The organ where protein digestion begins: Stomach, The organ into which the pancreatic juice and bile juice are, poured: Small intestine (Duodenum), iii) The enzyme which digests fat in ileum: Lipase, iv) The simplest form of carbohydrates: Glucose, v) The part of alimentary canal where water from the undigested, food is absorbed: Large intestine, vi) The end product of protein digestion: Amino acids, vii) Name the juice secreted by the liver: Bile juice, viii) Name the organ where bile juice is temporarily stored: Gall, bladder, Question and answers:, 1. Name the types of teeth present in the humans and state their, functions., Ans. INCISORS: They are chisel shaped helps in biting and, cutting., CANINES: They are pointed and help in tearing of food., PREMOLARS: They help in crushing and grinding the food., MOLARS: They too help in crushing and grinding of ingested, food., i) Name the juice secreted by the liver: Bile juice, ii) Name the organ where this juice is temporarily stored., Gall bladder, iii) Name the main function of the bile juice.

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2., , 3., , 4., , 5., , 6., , Ans. The bile juice breaks down fats into tiny droplets and this, process is called emulsification., Name the three enzymes found in the pancreatic juice and mention, their functions., Ans. The pancreatic juice contains enzymes namely amylase,, trypsin and lipase which help in the digestion of carbohydrates,, proteins and fats., i), Amylase acts on the starch converting it into maltose., ii) Trypsin converts proteins and peptones into peptides., iii) Lipase converts emulsified fats into fatty acids and glycerol., Name the three regions of the large intestine., Ans. The large intestine is about 1.5 meter long and consists of, three regions: the caecum, the colon and the rectum., Name the digestive juice secreted by the stomach and give its, function., • The gastric glands of stomach secrete gastric juice. The, gastric juice contains water, hydrochloric acid and enzyme, pepsin., • The acid kills the germs, prevents rotting of during its stay in, stomach and it activates the enzyme pepsin., • Pepsin converts proteins into a simpler compound called, peptones., • The protein casein present in the milk is converted into curd, by the help of another enzyme, the rennin., Define the term nutrition., Ans. The process by which all organisms obtain their food and, convert it into simpler substances, so they it can be absorbed and, utilized by the cells of the body is called nutrition., What is the role of liver and pancreas respectively in the digestion, of food.

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Ans. LIVER: The liver produces a greenish yellow fluid the bile, which is stored in the gall bladder, an organ found just below the, liver. The bile juice breaks down fats into tiny droplets and this, process is called emulsification., PANCREAS: Pancreas secretes pancreatic juice which is poured, into the duodenum through the pancreatic duct. The pancreatic, juice contains enzymes namely amylase, trypsin and lipase which, help in the digestion of carbohydrates, proteins and fats., 7. How is the small intestine best suited for the digestion and, absorption of food?, DIGESTION OF FOOD:, • The upper part of the small intestine or duodenum receives, secretions bile juice from the liver and pancreatic juice from, the pancreas., • The bile juice breaks down fats into tiny droplets and this, process is called emulsification., • The pancreatic juice contains enzymes namely amylase,, trypsin and lipase which help in the digestion of, carbohydrates, proteins and fats., ABSORPTION OF FOOD:, • The inner lining of the small intestine contains a large, number of tiny fingers like projections called villi.Each, villus has a network of thin blood vessels close to its, surface., • The surface of the villi absorbs the amino acids and glucose, to pass them into the blood system. The fatty acids pass into, special tubes called lymph vessels., • Vitamins and mineral salts are soluble in water and are directly, absorbed through the walls of the intestine.

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8. What do you mean by absorption of food?, Ans. The absorption of food means to pass the digested food, products into the blood system and lymph vessels to be used, further by body for various life functions., 9. Define the following terms;, EGESTION: The process of eliminating the undigested food, through the anus is called egestion., DIGESTION: Digestion is a process by which the complex, chemical compounds present in the food are break down into, simpler substances that are readily absorbed and utilized by the, body., ASSIMILATION: Assimilation is the utilization of the digested, food or nutrients by the body cells., 10., What is the fate of excess glucose in our body?, Ans. The excess glucose is converted by the liver into insoluble, glycogen and stores it. Whenever required the glycogen into, glucose., 11., Foods are classified into three groups on the basis of the, functions they perform in our body. Name these three groups, and, briefly state their functions. Also give two sources of each., • ENERGY GIVING NUTRIENT GROUP: Carbohydrates, and fats are included in this group. They give us energy to, carry out various functions. Rice, bread, potato are a few, sources of carbohydrates. Ghee, oil, butter are some sources, of fats., • BODY BUILDING NUTRIENT GROUP: Proteins are, included in this group. They help in the growth and repair of, our body. Milk, eggs, meat are rich in proteins., • PROTECTIVE NUTRIENT GROUP: Vitamins and minerals, are included in this group. They protect the body from

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12., •, •, •, •, , various diseases. Fish, green leafy vegetables and milk are, rich sources of vitamins. Fruits and vegetables ate the rich, sources of minerals., State the four ways in which saliva is useful to us., Ans. It moistens and lubricates the mouth cavity to make, speaking and swallowing easy., It cleans the mouth and destroys germs., The saliva binds the food particles and makes it into a mass, called the bolus., Saliva contains an enzyme amylase which helps in the, breakdown of starch to simple sugars., , END