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1. Slide 1: Science Interactive LTD Copyright 2005 Science Interactive LTD Multimedia CD-ROM for PC is a collection of 38 units totalling over 1150 PowerPoint slides matched to current single and double Science GCSE syllabuses. Each unit covers a wide range of different delivery and learning styles, offering an exciting way to involve your pupils during lessons or revision sessions. All styles of teaching and learning are supported through use of high quality images, graphics, challenging exercises and questions. Units can be used in the classroom via an interactive whiteboard, data projector or used during individual study via a PC or school network. Full users’ licence is available under our ‘comprehensive package’ or lessons can be purchased separately. Science Interactive LTD. PO BOX 50764 LONDON NW6 9AT email: sales@science-interactive.co.uk web: www:science-interactive.co.uk GCSE SCIENCE Unit 1: The Digestive System Unit 20: Crude Oil and its Products Unit 2: The Circulatory System Unit 21: Rock Cycle OCR Unit 3: Healthy Body and Immunity Unit 22: Elements, Molecules and Compounds EDEXCEL AQA Unit 4: The Respiratory System Unit 23: Ionic and Covalent Compounds Unit 5: Nervous System and the Senses Unit 24: The Halogens, their Uses and Compounds Unit 6: Human Homeostasis Unit 25: The Noble Gases, their Properties and Uses Unit 7: Hormones and the Endocrine System Unit 26: Rates of Reaction Unit 8: Drugs and Bad Body Maintenance Unit 27: Energy Unit 9: Photosynthesis in Green Plants Unit 28: Generating Electricity and its Domestic Use Unit 10: Water Transport in Plants Unit 29: Electricity Unit 11: Flow of Energy and Elements through the Environment Unit 30: Light and the Electromagnetic Spectrum Unit 12: Mitosis and Meiosis Unit 31: Radioactivity Unit 13: Inheritance and Selection Unit 32: Newton's Forces and the Effects of Forces Unit 14: Evolution and Human Impact Unit 33: Earth and Space Unit 15: Genetic Engineering Unit 34: The Earth and Plate Tectonics Unit 16: The Periodic Table and its Elements Unit 35: The Alkaline Earth Metals Unit 17: The Alkali Metals Unit 36: Sound and Hearing Unit 18: Metals and their Properties Unit 37: Natural Forces Unit 19: The Transitional Metals Unit 38: Cells, Tissue, Organs and Organs systems
2. Slide 2: Science Interactive LTD Copyright 2005 Unit 1  The Digestive System 
3. Slide 3: Unit 1: The Digestive System Science Interactive LTD Copyright 2005 Understand: Keywords: What are the seven food groups and their role in 1. Nutrition, Nutrients, Food, Groups, Fats, a healthy balanced diet. Carbohydrates, Proteins, Minerals, Vitamins, The chemical tests to detect the presence of 2. Fibre, Water, Digestive, System, Physical, proteins, lipids, carbohydrates or sugar in foods. Chemical, Villi, Breakdown, Absorption, What the recommended daily amounts of 3. Nutrients, Amino acids, Glucose, Fatty acids, vitamins and minerals are in a healthy diet. Glycerol, Obesity & Malnutrition. The role of the digestive system and its key 4. organs during the physical and chemical breakdown of food. The role of enzymes during the chemical 5. breakdown of foods. How enzymes function as catalysts. 6. The role of the villi tissue in the absorption of 7. nutrients from the gut into the blood. The fate of these nutrients in the body and their 8. assimilation into cells and tissues. The health consequences of overeating and 9. under eating. 10. The importance of getting the balance right. Click mouse to begin Science Interactive LTD PO BOX 50764 LONDON NW6 9AT web: www.science-interactive.co.uk email: sales@science-interactive.co.uk
4. Slide 4: Science Interactive LTD Copyright 2005 Overview of the digestive system The digestive system is a collection of cells, t________ and organs that function together to breakdown and absorb the daily essential nutrients, minerals and vitamins required for healthy growth and development. The digestive system is able to breakdown proteins, fats and carbohydrates prior to their absorption into the bloodstream. These large food molecules are broken down into smaller molecules by both physical and chemical d________. Name a cell, tissue and organ that belongs to the digestive system ? The digestive system: Word bank: tissues digestion Diagram of the digestive system Organ Function (complete table) Chews foods, using canines, incisors and molars. Mouth Oesophagus __________________________________ ? Stomach __________________________________ ? Liver __________________________________ ? Small Intestine __________________________________ ? Large Intestine __________________________________ ? Rectum __________________________________ ? Anus __________________________________ ?
5. Slide 5: Science Interactive LTD Copyright 2005 Dietary intake of foods Our dietary intake of foods like proteins, carbohydrates and lipids should provide us with the correct amount of c________ energy to maintain our daily activities, growth (if we are children) and repair. An adult male requires about 10,500 kilojoules per day, equivalent to about 100 joules per second. This is the same energy that a 100 watt light bulb uses. Taking too much energy, by perhaps consuming too much raw sugar or fat, can lead to weight gain, high blood pressure and eventually o________. Daily energy requirements: Word bank: chemical obesity Dietary intake, assimilation and respiration Dietary energy Respiration Diagram Respiration C6H12O6 6H2O Mitochondria Energy 6O2 6CO2 Growth & reproduction Assimilation 10,500 kJ/day (adult male) All the chemical energy, vitamins and minerals that we require are provided by a balanced diet. Notes Overeating or under eating, eating too little vitamins and minerals can cause many health problems in adults and children. It is estimated that one in four adults in the Britain will be clinically obese by 2010.
6. Slide 6: Science Interactive LTD Copyright 2005 Deficiency diseases Your diet needs to be b____________, providing all the necessary v_________ and minerals that you require for healthy growth and development. In some areas of the World, poor diets lacking in just one or two minerals or vitamins causes deficiency diseases. Scurvy is a good example of a deficiency disease that was common amongst sailors during the 17th and 18th centuries. This disease was caused by a lack of vitamin C contained in fresh fruit and vegetables, then unavailable during the long sea voyages. Scurvy can lead to bleeding of gums and the general deterioration of muscles and joints. Deficiency diseases: Word bank: balanced vitamins Vitamin C Calcium Vitamin D Vitamin A Diagram Deficiency Scurvy Osteoporosis Rickets Night blindness Scurvy: Gums begin to bleed and old wounds begin to open. Limes were carried and included in a sailors Notes diet to avoid scurvy. Osteoporosis: A diet lacking in calcium leads to poor teeth and bone development. In older age, bones become weak and break easily. Ricketts: A lack of vitamin D causes soft bones during a child’s growth. This disease is known as rickets. Vitamin D is produced by the skin during the summer months. Night blindness This is a result of too little vitamin A in the diet.
7. Slide 7: Science Interactive LTD Copyright 2005 A balanced diet The amount of energy (kJ) we consume through our diet and the recommended daily amount of m________ and v___________ we need for normal healthy growth and development is given by the table below. Notice that these values depend on our age, our sex, when female if we are pregnant or lactating and even our lifestyles. The amount of e_______ we need can also depend on the type of job we have, for example a labourer digging roads will require more energy from their diet than someone who works in an office. Look at the information given by the table and answer the questions. Daily vitamin, mineral and energy requirements: Word bank: minerals vitamins energy Sex Age Energy Body Wt. Protein Vit A Vit C Vit D Iron Calcium Units Years kJ kg g mg mg ug mg mg Male 15 12500 59 59 1.1 60 10 12 12000 Male 35 10500 80 63 1 60 10 10 10000 Female 15 9750 55 44 0.8 60 8 15 12000 Female 35 9750 63 50 0.8 60 8 15 12000 Female (pregnant) 35 + 1000 + 12 60 0.8 70 10 30 13000 Female (lactating) 35 +2000 63 65 1.3 75 12 15 14000 Questions: 1: Why does a 15 year old male require more energy than a 35 year old male. 2: Why do females require more iron than males. 3: What role does vitamin C and calcium play in the body. 4: Why do you require less vitamin D in the summer when compared to winter. 5: Why does a lactating female require the most protein in her diet.
8. Slide 8: Science Interactive LTD Copyright 2005 Nutrition and food groups one There are seven basic food groups essential for a healthy d______. The three main food groups p________, fats and carbohydrates provide us with all the energy requirements as well as having specific functions in the body. Carbohydrates should make up about 55% of your total daily kilojoule intake. Too much fat in your diet can lead to blocked a_______ and obesity. Protein is required most during p_______ in adolescents for growth and repair. Compare the diets of a body builder, adolescent female and male and a pregnant female, how might they differ ? Proteins, carbohydrates and lipids: Word bank: diet proteins arteries puberty Proteins Lipids Carbohydrates Diagram For growth and repair. During Store of energy. Insulates the Converted readily to glucose by Function puberty protein demand is very body against the cold. High lipid carbohydrase enzymes found in high. Why do body builders diet lead to atherosclerosis and mouth saliva and the small take a high protein diet ? obesity. 1 in 5 adults are obese. intestine. Glucose is then respired in cells. Sources Animal flesh, Soya bean ____________________ _______________________ and nuts. ___________________? ____________________?
9. Slide 9: Science Interactive LTD Copyright 2005 Nutrition and food groups two The other four food groups, although they do not provide the body with any energy, are all essential for healthy g_______ and development. A balanced diet supplying all the necessary vitamins and minerals comes from eating a diet containing low fat meat, plenty of carbohydrates, fresh f_____ and vegetables. Many foods sold in supermarkets now have vitamins and minerals added to them, so that we can all take our recommended daily amount. Vitamins, minerals, roughage and water: Word bank: growth fruit Vitamins Minerals Roughage Water Diagram Healthy tissue growth Healthy tissue growth Helps keep regular Correct hydration is Function and development. and development. A bowel movements. A essential for every cell Lack of vitamins lack of iron causes low fibre diet and of course normal leads to deficiency anaemia of the blood. increases the risk of blood pressure. How diseases like scurvy Low calcium affects contracting large much water should you and rickets. bone growth. bowel cancer. drink every day ? Sources All fresh fruit and _______________ ______________ _________________ vegetables. ______________? _____________? ________________?
10. Slide 10: Science Interactive LTD Copyright 2005 Food tests one The presence of proteins, starch, sugars and l_______ in foods can be tested for by using ‘food tests.’ Scientists test foods for the presence of each of these food groups so they can provide nutritional information on their food products. Where is this information normally found on a packet of crisps or a chocolate bar ? Food tests: Word bank: lipids Protein Lipid Starch Sugar Diagram Biuret’s test Paper test Iodine test Benedict's test Test Add 5cm3 of copper Place a small amount Place 6 drops of iodine Add 5cm3 of benedict’s sulphate and 5cm3 of of tested food on water on food sample. solution. Heat tube in sodium hydroxide. paper. Allow to dry. hot water for 5 minutes. Paper goes clear with lipids Result Control Positive Control Positive Control Positive lipid food test
11. Slide 11: Science Interactive LTD Copyright 2005 Food tests two Starch, a polymer of g_______ is found in many foods including all cereals and most vegetables. Starch is broken down by the carbohydrase e________ to glucose. In this form, glucose is readily absorbed and transported to the many billions of cells in the body. Glucose is oxidised with oxygen during cellular respiration to provide energy essential for life. Although glucose is essential for cellular respiration, which disease might you suffer after years of eating a high glucose diet ? Testing for starch in foods: Word bank: glucose enzyme Starch solution Corn Apple Sucrose solution Diagram Starch ? Starch ? Starch ? Starch ? Results Yes Yes Yes Yes No No No No
12. Slide 12: Science Interactive LTD Copyright 2005 Function of the digestive organs one Each organ or tissue in the digestive system has a specific function that helps break down the three main food groups (proteins, lipids and carbohydrates) into small molecules so they can be a_________ into the blood stream. The majority of e___________ that chemically breakdown foods are released by the pancreas into the small intestine. After carbohydrate, protein and lipid breakdown, their products; sugars, amino acids, fatty acids and glycerol are absorbed across the villi into the blood stream. Why can only small food molecules like glucose cross from the gut into the blood ? Digestive organs: Word bank: absorbed enzymes Teeth Food pipe Stomach Small intestine Diagram Chews food and secretes Sends contents to Adds acid and proteases Most enzymes are found Notes salvia which lubricates stomach by squeezing to begin protein here. Lipids, proteins the food and contains the chewed food (bolus) breakdown. The stomach and carbohydrates are enzyme carbohydrase, This process is called has a pH of around 2. broken down before which begins to break peristalsis. Gravity also This also kills any they are absorbed into down carbohydrates. helps this process. bacteria found in food. the blood across the villi.
13. Slide 13: Science Interactive LTD Copyright 2005 Functions of the digestive organs two All nutrients including amino acids and glucose and other food groups including water, minerals and vitamins are absorbed by the v______ found in the small intestine. The remaining organs of the digestive system including the large intestine and colon remove water from undigested material, helping to form a solid stool. The rectum stores the waste faeces until its excretion via the anus. Blood takes the nutrients to the l_______ where they are processed and sent via the circulatory system, the billions of cells in the human body. Digestive organs: Word bank: villi liver Liver Pancreas Large intestine Rectum and anus Diagram Processes all nutrients The pancreas is found The large intestine The rectum stores the Notes like amino acids, behind the stomach. absorbs and recycles solid waste which glucose, fatty acids and The pancreas makes water. The stool begins contains undigested food glycerol. Also breaks and releases all the to become solid. This (fibre), bacteria, water down excess amino acids enzymes found in the makes it easier to store and broken down blood small intestine. by the rectum. cells. forming urea.
14. Slide 14: Science Interactive LTD Copyright 2005 Physical digestion The breakdown of proteins, carbohydrates and lipids begins with chewing. Humans have a mixture of c_______, incisor and molar teeth which are designed to cope with a varied diet, which includes animal flesh and vegetables. Our canines and incisors tear and rip food. Our molars, with their flat profile are designed to grind and chew fibrous vegetable matter like root vegetables and fruits. How does a high sugar diet affect our teeth and lead to tooth decay ? Human teeth and physical digestion: Word bank: canine Teeth Human teeth Brushing Diagram Humans have two sets of The tooth (incisors, canines and Modern toothpaste now Notes teeth. Your milk teeth are molars) are capped with white enamel. contains fluoride which replaced when you are This is made from calcium carbonate helps control oral bacteria about eight years old. Your and is the hardest substance in the and prevents tooth decay. final molars appear in your body. It can be eroded by acids found Always have a 6 monthly twenties. in foods or produced by oral bacteria. check-up at the dentist.
15. Slide 15: Science Interactive LTD Copyright 2005 Enzymes and chemical digestion Digestive enzymes break down large f_____ molecules into smaller ones. Enzymes are all proteins, and are very specific, only having one substrate like a protein or a lipid. They behave like c_________, able to speed up the rate of reaction and can be recycled by the digestive system. There are three main types of enzymes found in the digestive system: proteases, carbohydrases and lipases. Look at the table below to find out the function and location of each type ? Types of digestive enzymes: Word bank: food catalysts lipases Proteins Carbohydrates Lipids Diagram Enzymes Proteases Carbohydrases L_________ -stomach -salivary -pancreatic -pancreatic -pancreatic Products Sugars Amino acids Fatty acids and glycerol
16. Slide 16: Science Interactive LTD Copyright 2005 How enzymes function one For proteins, lipids and c____________ to be absorbed from the small i_________, into the blood, they must be broken down into small molecules. Digestive enzymes breakdown food chemically. An enzyme’s substrate will bind to the enzyme’s a_________ site where chemical bonds are broken producing smaller molecules which can then be absorbed into the b________ stream. How enzymes break down food molecules: Word bank: carbohydrates intestine active blood Stage one Stage two Stage three Diagram SubstrateSubstrates Products Enzyme substrate complex active site active site active site Enzyme Enzyme (can be reused) Enzyme (catalyst) Products Notes Step one Step two Step three Substrates like proteins, Chemical bonds are broken New products like glucose are carbohydrates and lipids bind by the enzyme to form formed which then leave the to the enzyme’s active site. monomers. enzyme’s active site.
17. Slide 17: Science Interactive LTD Copyright 2005 How enzymes function two Enzyme are biological catalysts which will increase the rate of b__________ of proteins, carbohydrates and lipids without be used up themselves. Enzyme catalysts are able to lower the activation energy required for new products like sugars and amino acids to be produced from substrates like carbohydrates and proteins. The reaction takes place in an area of the enzyme which is called the active site. Carbohydrases, Lipases, Proteases Enzymes are biological catalysts Not used up during the reaction Lower the activation energy Enzymes as biological catalysts: Word bank: breakdown Breakdown of carbohydrates by carbohydrase Carbohydrase + Carbohydrate Carbohydrase + sugar molecules Diagram Sugar e Sugar rat Sugar hyd bo Sugar Car Sugar Catalyst Catalyst Enzyme Enzyme active site active site active site active site Notes Substrates like carbohydrates collide and temporarily bind to the enzyme’s active site on its surface. The bonds in the substrates are weakened by the enzyme. The bonds are broken and new products are formed. These products (sugar) then leave the enzyme’s active site, leaving the enzyme catalyst unchanged and able to participate in further reactions.
18. Slide 18: Science Interactive LTD Copyright 2005 How enzymes function three A human body contains many hundreds of different enzymes found inside cells and as part of the d_________ system. Without enzymes, which catalyse the breakdown of nutrients like proteins, carbohydrates and fats, digestion would be too slow to support all your functions. Like many of the inorganic catalysts, enzymes lower the activation energy and increase the rate of reaction without being used up. With enzymes, the rate of reaction increases as the t___________ increases, doubling for every 10oC rise in temperature. However, above approximately 40oC, enzymes are denatured or destroyed and will stop working altogether. Name three types of enzymes found in the human gut ? Biological enzymes as catalysts: Word bank: digestive temperature How enzymes speed up the rate of reaction Heat sensitive enzymes With inorganic catalyst Substrates with sufficient energy to form new products Rate of reaction With enzyme With enzyme Without enzyme 0 Temp oC 40 60 80 100 A catalyst will lower the activation required for substrates to react As you increase the temperature by 10oC the with one another to form new products. The graph above shows how rate of reaction doubles until around 40-45oC by adding a catalyst, the activation energy shifts to the left increasing where the high temperature denatures or the number of successful collisions and therefore increasing the rate of destroys the enzyme. Inorganic catalyst like reaction. Enzymes are highly specific for their substrate. iron and nickel are not temperature sensitive.
19. Slide 19: Science Interactive LTD Copyright 2005 Using enzymes as catalysts Enzymes are used in a wide variety of industrial applications. Enzymes found in yeast cells are used for f___________ sugar during alcohol production and making bread. Enzymes found in the bacteria lactose bacillus are used to produce lactic acid from milk lactose. This is the first step in the production of cheese and dairy yoghurts. Other enzymes are found in modern biological w_________ powders that digest stains on clothing. These modern washing powders work at relatively low temperatures (<40oC) and are energy efficient because you don’t need to use high water temperatures. What temperature would be best to produce cheese from milk ? Biological enzymes as catalysts: Word bank: fermenting washing Alcohol Washing powders Bread manufacture Diagram Notes Yeast is an essential bacteria All biological washing Yeast is used during bread containing enzymes used to powders contain enzymes that making. The carbon dioxide gas ferment sugar from grape, fruit help with the removal of food produced during the respiration or wheat into alcohol. stains. These enzymes digest of wheat sugars and Fermentation of sugar must be and breakdown the stains at carbohydrates cause the bread done in an oxygen free very low temperatures... dough to rise. This gives the environment. below 40oC. bread its light texture.
20. Slide 20: Science Interactive LTD Copyright 2005 Absorption of nutrients by the villi Once proteins, lipids and carbohydrates are broken down into amino acids, sugars, fatty acids and glycerol, absorption into the blood stream takes place in the small intestine. The small intestine is well designed for absorption of n___________ into the blood stream. It has a thin lining, large s_________ area and a good blood supply. The surface area of the small intestine is about 10 metres squared. To achieve this huge surface area, the small intestine has a folded lining, is very long and contains millions of tiny microscopic villi. These are finger like projections which increase the surface area and help nutrient absorption into the blood. Absorption across the villi into the blood stream: Word bank: nutrients surface Small intestine Features of the small intestine villi (Villi (x 10,000 Magnification)) Diagram Fatty acids glycerol Glucose Amino acids Artery Lymph vessel Vein There are many millions of villi found on the surface of the small intestine. They have thin walls and have a Notes very rich blood supply. Amino acids and glucose are absorbed into the blood. Fatty acids and glycerol are absorbed into the lacteal, which then drains into the lymph system.
21. Slide 21: Science Interactive LTD Copyright 2005 Breakdown of foods along the digestive tube The digestive system is simply a long tube where large nutrient molecules are converted to small molecules. In the small intestine, nutrients like g_________ and amino acids are absorbed across the villi into the hepatic artery. Here they travel to the liver and are either used immediately, stored or assimilated into your cells. Look at the overview of digestion and find out where protein, carbohydrate and lipid digestion occurs ? Overview of digestion: Word bank: glucose proteins water Digestive system Key P_______ ? G________ ? Carbohydrate Fatty acids and glycerol Lipids Waste W_______ ? Stool Amino acids Blood cells Hepatic artery to the liver Oesophagus Small intestine Large intestine Rectum Anus Stomach
22. Slide 22: Science Interactive LTD Copyright 2005 Assimilation of nutrients After the digestion of proteins, carbohydrates and lipids by the digestive system, g_________ and amino acids are absorbed across the villi into the hepatic artery. Here they travel to the liver and are either used immediately, stored or assimilated into your cells. Glucose is either respired or stored in muscle and liver as glycogen. Amino acids are used to build p______ like enzymes. Excess amino acids are broken down by the liver to form urea. Fatty acids and glycerol, which are absorbed into the lymph system are used to make cell membranes, some hormones or are stored under the skin. What two hormones control the amount of glucose in your blood stream ? Nutrient assimilation: Word bank: glucose proteins Digestive system Small intestine Nutrient use C6H12O6 6H2O Respiration Liver Mitochondria Energy 6O2 6CO2 Cells Blood stream Fat Assimilation Glucose Amino acids Fatty acids Amino acids Glucose Fatty acids & glycerol Muscle
23. Slide 23: Science Interactive LTD Copyright 2005 Getting the balance wrong one A healthy balanced diet should provide you with the right amount of chemical energy, vitamins and minerals. It should also be relatively low in f___ and protein (adult) and high in carbohydrates. Eating too much fatty or sugary foods, low in vitamins and minerals for long periods of time may lead to health problems later on in life. D______, atherosclerosis, obesity and heart disease are all associated with eating a poor diet. It is estimated that obesity will be the number one killer in the next twenty years in Britain. Consuming the wrong foods: Word bank: fats diabetes Pizza Chips Fast Food Sweets and chocolates Diagram Notes With an ever increasing choice of cheap fatty fast foods, children are now more overweight and less fit when compared to children of the seventies. Obesity, diabetes and in some cases heart disease are now no longer diseases of the old. Children need to avoid ‘junk food’ and eat a more balanced diet containing the right quantities of all of the seven food groups.
24. Slide 24: Science Interactive LTD Copyright 2005 Getting the balance wrong two Your brain regulates your appetite and signals when you are h______. Your body is able to regulate the amount of chemical energy that you take over many years. Consuming foods high in sugar and fat and low in bulk tend to upset the right balance. Excess chemical energy in your diet leads to greater assimilation, weight gain and eventually obesity. Some individuals who are grossly obese, store upwards of a million additional kilojoules in their body as f___. What health consequences does obesity in humans cause ? Over consumption of nutrients: Word bank: hungry fat Dietary intake in excess of daily requirements Respiration Dietary energy Respiration Diagram C6H12O6 6H2O Mitochondria Energy Assimilation 6O2 6CO2 Obesity Dietary intake in excess of 10,500 kJ/day (adult male) All the chemical energy, vitamins and minerals that we require are provided by a healthy balanced diet. Notes Overeating or under eating, eating too little vitamins and minerals can cause many health problems in adults and children. It is estimated that one in four adults will be clinically obese by 2010.
25. Slide 25: Science Interactive LTD Copyright 2005 Getting the balance wrong three Poverty, drought, disease and war can lead to the failure of crops and livestock. In severe cases of famine, for example the famine in Ethiopia in 1984, millions of people may starve to death. The very old and y_______ are particularly vulnerable. Malnutrition can lead to low body weight, weak immune systems and poor development in children. Famine and malnutrition is still widespread in Africa. Live 8 is now putting pressure on the eight richest countries (G8) to reduce Africa’s debt burden. This should reduce the level of poverty and starvation in Africa. Under consumption of nutrients: Word bank: young Dietary intake below daily requirements Respiration Dietary energy Respiration Diagram C6H12O6 6H2O Mitochondria Energy 6O2 6CO2 Malnutrition Dietary intake below Assimilation 10,500 kJ/day (adult male) Malnutrition in Africa and other developing countries is common place where daily income is less than Notes one pound a day. Many children have less food than they require to live. It is estimated that every three seconds someone dies because of starvation.
26. Slide 26: Science Interactive LTD Copyright 2005 Getting the balance right one Over the last 200 years, here in Western Europe our life expectancy has increased partly due to our healthy diets. Eating a low fat, medium protein, high fibre and carbohydrate diet containing lots of minerals, v________, fresh fruit and vegetables is important so that we maintain our correct b_____ weight. In schools, less junk food and more freshly prepared meals are now being offered to pupils, due to parental pressure and Jamie Oliver, the famous chef who has begun to campaign for better school diners. Good lifelong eating habits: Word bank: body weight Dietary intake in excess of daily requirements Diagram Healthy growth and development over your lifetime requires sensible eating and a balanced diet. Respiration Malnutrition Assimilation Dietary intake at 9,750 kJ/day A balanced diet is important for our long life expectancy. Overeating or under eating, eating too little Notes vitamins and minerals can cause many health problems in adults and children. In order to reach your old age, eat a healthy balanced diet...its that simple !
27. Slide 27: Science Interactive LTD Copyright 2005 Getting the balance right two Our dietary intake of foods like p________, carbohydrates and lipids should provide us with the correct amount of chemical energy to maintain our daily activities, growth (if we are children) and repair. An adult male requires about 10,500 kJ per day, equivalent to about 100 joules per second. This is the same energy that a 100 watt light bulb uses. Also research shows, that eating five portions of f____ and vegetables a day reduces the risk of developing heart disease, colon cancer and obesity. How can you get children to eat more fruit and vegetables ? Healthy diets: Word bank: proteins fruit Steamed potatoes Carrots Fresh fruit Cereals Diagram Eating sufficient quantities of fresh fruit and vegetables helps us avoid many of the lifestyle diseases Notes like obesity, cancer and diabetes. It is recommended that we all eat at least five portions of fruit and vegetables every single day. Fruit and vegetables are an excellent source of all the minerals and vitamins that we require like vitamin C. This helps us to avoid deficiency diseases like scurvy.
28. Slide 28: Science Interactive LTD Copyright 2005 Extension questions and homework 1: Define the following terms: Physical digestion, Chemical digestion, Enzymes, Excretion, Nutrients, Minerals, Vitamins, Fibre, Absorption, Assimilation & Catalyst. 2: Look at the diagram of the three endocrine glands. Complete the table. Roast potatoes Boiled potatoes Fried potatoes Cooking method Healthy option Rich in minerals and vitamins Roasting Boiling Frying 3: Answer the following questions: a) The type of teeth we find in an animals mouth can tell us some information on their diet...how. b) What is peristalsis and how does saliva help this process. c) Acid is added to food in the stomach, what is the function of stomach acid. What is the pH of stomach acid. d) Draw a flow chart to show what happens to food as it passes from the mouth to the anus. e) What is the function of bile during the digestion of lipids. Where is it produced. f) What enzyme breaks down carbohydrates to glucose. Where is this enzyme found along the gut. g) What’s the role of the intestine’s villi and where do nutrients travel once they’ve reached the blood stream.
29. Slide 29: Science Interactive LTD Copyright 2005 4: Look at the information in the table below. Use the following table to answer questions a to d. Person Energy (kJ) Protein (g) Carbohydrate (g) Fats (g) Iron (mg) Vitamin C (mg) Male 10 -12 10800 30 230 45 45 20 Female 10 -12 9700 28 220 39 56 20 Adult male 12900 39 256 54 76 35 Pregnant female 14500 45 260 35 150 40 a) Describe any differences between males and females in children and adults. b) What role do proteins, carbohydrates, fats, vitamin C and iron play in the human body. c) Why does the pregnant female require huge quantities of iron and protein. d) What would a male doing an active job require in kJ/day. 5: Answer the following questions: a) Most western diets contain too much fat and salt. What health problems will this cause. b) Why is tooth enamel the hardest substance in the human body. c) What are the four main types of teeth. Is there a relationship between the diet an animal has and the types of teeth they have. d) Which type of teeth are not present in your milk set, but are present in your permanent set. e) What causes tooth decay. Draw three diagram to show the main stages of tooth decay. f) Compare the causes and effects of starvation and overeating in humans. g) What health problems are caused by obesity in humans.
30. Slide 30: Science Interactive LTD Copyright 2005 6: Look at the information in the table below. Complete the table. Vitamin /mineral Rich food sources Function in the body Deficiency disease A Carrots, milk and dairy products Good eyesight and skin Poor vision and skin C Tissue repair and immune system D Fish oil, dairy and made by body in sunlight Rickets Iron Red meat and liver Calcium Strong teeth and bones Soft bone and teeth 7: Answer the following questions: a) Write a paragraph to explain the action of enzymes in digestion. Include the following words: Protease, Amylase, Absorption, Proteins, Carbohydrates, Lipids, Amino-acids, Fatty-acids, Glycerol, Glucose, Blood, Capillaries and Villi. b) What do you think is the main enzyme needed to break down the following foods: Fish, Bread, Butter, Rice, & Chicken. c) Look at the diagram of the digestive system. Match the organs to the following functions: (i) Absorbs water (ii) Contains proteases and acid (iii) Stores faeces (iv) Allows faeces to pass out of the rectum (v) Joins the throat to the stomach (vi) Most absorption of nutrients happens here (vii) Where most food molecules are broken down (viii) down by pancreatic enzymes. (ix) Stores and release bile. Internet: Go to google.co.uk and find how glucose is used by cells during cellular respiration. Cut and paste a diagram to show how cells use sugar during cellular respiration. What are the end products and how are they excreted.