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Revision – Part 2 1. Fill in the 10 un-shaded boxes (5 mark) Nutrient One function in the body – One of the following answers Vitamin C Resist infection, promote healing, maintain healthy skin, gums, teeth, blood vessels, promotes absorption of iron and calcium, metabolise proteins and manufacture hormones, support folic acid and vitamin E in their functions Vitamin B3 Niacin Metabolise proteins, carbohydrates, fats, healthy skin, maintenance of both the digestive and nervous systems Folate Metabolism of proteins, Formation of DNA and RNA within cells, Phosphorus Found in bones and teeth. One food it can be found in, One of the following answers citrus fruits potatoes leafy greens tomatoes One excess/deficiency it can cause as indicated One of the following answers Whole grain cereals, red meat, poultry, seafood, nuts and legumes Deficiency Disturbance of digestive and nervous systems, pellagra Whole grain cereals, leafy greens, milk, peanuts, avocadoes, yeast and yeast extracts, organ meats Deficiency Anaemia during pregnancy, sterility in males and females, neurological diseases – ie Spina Bifita Large blood cells are produced with low folate levels and this affects white blood cell and platelet numbers – which affects blood clotting. Can affect lining of the gut and therefore hamper transfer of nutrients from the gut to the bloodstream Deficiency Lean meat, poultry, fish, eggs, bran, cheese, milk Deficiency Scurvy Body cannot absorb correct amounts of calcium 2. List the two types of fibre, explain their function within the body and state a food that contains this type of fibre (6 marks) (i) Type Soluble Fibre Function attracts water and turns to gel during digestion may help lower cholesterol Allows nutrients to be released more slowly Food Sources: oat bran, barley, nuts, seeds, beans, lentils, peas, Green leafy Veg (ii) Type Insoluble Fibre Function adds bulk to the stool appears to help food pass more quickly through the stomach and intestines Feeling of satiety Food wheat bran, vegetables, and whole grains , Wholegrain bread, Skin of fruit and veg 3. Complete the table below Basic building block List type and food source List two functions in the body 1a Monosaccharide 1. Carbohydrate 1. Glucose 2. Galactose 3. Fructose 2. b) Example Glucose Galactose Fructose 1. To provide energy 2. To stimulate the digestive system 3. To regulate the use of protein by the body c) Food source Glucose (honey, grapes, ripe fruits) Galactose (dairy) Fructose (fruit) 3. 2a. Disaccharide 4. b) Example Sucrose Lactose Maltose c) Food source Sucrose – fruit and Veg Lactose - Dairy Maltose - beverages, beer, cereal, pasta, potatoes and in many processed products which have been sweetened. 5. 3a Polysaccahride b) Example Starch Soluble Fibre Insolube Fibre Food source Starch – Pasta, Rice, Corn Soluble Fibre - oat bran, barley, nuts, seeds, beans, lentils, peas, green leafy veg Insolube Fibre – wheat bran, vegetables, and whole grains, wholegrain bread, apple skin, Protein 1. Amino Acids 1. Complete protein food source Any animal product OR soy products 1. To build, maintain and repair muscle tissue 2. To build antibodies 2. Incomplete protein food source Plant based sources 3. To activate the growth hormone 4. Create proteins (hemoglobin) and enzymes 4. Explain why the villi are so effective at transferring nutrients from the digestive tract to the blood stream? (2 marks) The villi increase the surface area of the digestive tract, thus providing a greater area over which the uptake of nutrients can occur. The walls of the vili are very thin so absorption of glucose, amino acids, water soluble vitamins and minerals can occur 5. Calculate the BMI of a woman aged 24 who weighs 72kg and is 180cm tall. Show all working out. 4. An sedentary adolescent female has the following daily energy intake: 200 g carbohydrate – 200g X 16kj = 3,200kj 80 g protein 80g X 17kj = 1,360kj 100 g fat 100g X 37kj = 3,700kj a) Calculate, as percentages, the energy distribution of the total carbohydrates, protein, and fats in the adolescent’s energy intake. The total energy intake is 8260kJ (Show all calculations and answers to the nearest whole number). (3 marks) (i) Carbohydrates 3,200kj / 8260 = 39% (ii) Protein 1,360kj / 8260 = 16% (iii) Fats 3, 700kj / 8260 = 45% 5. David is a 40-year old man who weighs 84 kilograms. His daily energy intake is 12500 kilojoules. His daily energy expenditure is made up of the following activities: 30 minutes of jogging = 1115kJ 1 hours of very light activity (dressing, reading) = 500 kJ The thermogenic effect of food accounts for 10% of his total daily kilojoule intake: a) Calculate his basal metabolic rate, showing calculations 84 x 1.0 x 24hrs x 4.2 = 8,467.2kj b) (1 mark) b) Calculate thermic effect of food The thermic effect of food is the energy used in digestion, absorption, metabolism and the storage of ingested nutrients. Thermic effect of food is estimated at 10% of energy intake =10 / 100 x 12500 = 1250kj c) Calculate his total daily energy expenditure BMR 8,467 kj + 1250 kj (10% thermic effect) + exercise 1,615 kj = 11,332 daily energy expenditure Energy intake = 12,500 Minus expenditure -11332 = 1168kj d) Positive balance will gain weight at this continued pattern 6. a) On the following diagram, make annotations to show how/where a buttered roll is digested. (The buttered roll is mostly carbohydrate and fat, almost no protein) (3 marks) Mouth Mechanical Physical – salivary amylase breaks down starch in bread roll Maltose Liver Stomach Produces bile for emulsification of fats Food combines with gastric juices to produce chime. Gastric juices contain HCL, this uncoils proteins and allows enzyme pepsin to break proteins– into Pancreas send peptones. pancreatic enzymes to duodenum and completes breakdown of F,C & P Gall Bladder Stores Bile Duodenum Lipases break down fat once it has been emulsified by bile Large intestine – break down of soluble fibres by bacteria and products absorbed b) What role does the gall bladder play in the digestion of fat? (1 mark) Stores and releases bile into digestive system. The bile emulsifies fats into smaller droplet to increase surface area for more efficient enzyme breakdown by lipases. c) Complete the table below. Location in the digestive system An enzyme involved in digestion at this site Mouth Amylase (carbohydrate) Stomach Peptases / pepsin Small intestine a) Fat - lipase b) Carbohydrate - maltase, sucrase, lactase, pancreatic amylase c) Protein - proteases C) Describe the digestion of lipids in the small intestine (2 marks). Bile released from the liver emulsifies fat into smaller globules. The enzyme lipase, which is excreted from the pancreas, then converts fats into fatty acids and glycerol. 7. Describe the role of mechanical digestion of protein in the stomach ( 2marks). The muscle lining the stomach churns the food, which mixes with the gastric juices to produce chime. 8. Describe the chemical digestion of protein in the stomach (2 marks). The enzyme pepsin starts the breakdown of proteins into smaller chains of amino acids. 9. Complete the table below. (6 marks) Macronutrient Site of Digestion One Enzyme Involved in Digestion End Product of Digestion Protein Stomach Pepsin, HCL Amino Acids Lipids Small Intestine Lipase Glycerol & Fatty Acids Carbohydrate Small Intestine Amylase Glucose 7a) Describe the difference between haem and non haem iron. (2 marks) Haem iron is readily absorbed by the body and meat and fish supply haem iron. Non haem iron is not as readily absorbed and is found in plant sources. b) Name a micronutrient that can help increase the absorption of the iron contained in spinach. Vitamin C (1 mark) c) Name a food that inhibits the absorption of iron. (1 mark) Fibre if large amounts of unprocessed bran is consumed and coffee d) Give two reasons why we need to consume iron. (2 marks) Formation of red blood cells in the protein haemoglobin and forms part of myoglobin in muscles (makes oxygen available for muscle contraction)