1. How we ingest, digest, absorb and assimilate what our cells need NUTRITION AND DIGESTION

2. SPECIFICATION: BIOLOGICAL MOLECULES 1: NUTRIENTS 2.5 identify the chemical elements present in carbohydrates, proteins and lipids (fats and oils) 2.6 describe the structure of carbohydrates, proteins and lipids as large molecules made up from smaller basic units: starch and glycogen from simple sugar; protein from amino acids; lipid from fatty acids and glycerol 2.7 describe the tests for glucose and starch

3. SPECIFICATION: BIOLOGICAL MOLECULES 2: ENZYMES 2.8 understand the role of enzymes as biological catalysts in metabolic reactions 2.9 understand how the functioning of enzymes can be affected by changes in temperature, including changes due to change in active site 2.10 understand how the functioning of enzymes can be affected by changes in active site caused by changes in pH 2.11 describe experiments to investigate how enzyme activity can be affected by changes in temperature.

4. SPECIFICATION: NUTRITION 1: DIET 2.23 understand that a balanced diet should include appropriate proportions of carbohydrate, protein, lipid, vitamins, minerals, water and dietary fibre 2.24 identify sources and describe functions of carbohydrate, protein, lipid (fats and oils), vitamins A, C & D, and the mineral ions calcium & iron, water & dietary fibre as components of the diet 2.25 understand that energy requirements vary with activity levels, age and pregnancy 2.32 describe an experiment to investigate the energy content in a food sample

5. SPECIFICATION: NUTRITION 2: THE ALIMENTARY CANAL 2.26 describe the structures of the human alimentary canal and describe the functions of the mouth, oesophagus, stomach, small intestine, large intestine and pancreas 2.27 understand the processes of ingestion, digestion, absorption, assimilation and egestion 2.28 explain how and why food is moved through the gut by peristalsis 2.31 describe the structure of a villus and explain how this helps absorption of the products of digestion in the small intestine

6. SPECIFICATION: NUTRITION 3: CHEMICAL DIGESTION 2.29 understand the role of digestive enzymes, to include the digestion of starch to glucose by amylase and maltase, the digestion of proteins to amino acids by proteases and the digestion of lipids to fatty acids and glycerol by lipases 2.30 understand that bile is produced by the liver and stored in the gall bladder, and understand the role of bile in neutralising stomach acid and emulsifying lipids

7. Chemical elements in the major nutrients 2.5 identify the chemical elements present in carbohydrates, proteins and lipids (fats and oils) Carbon, CHydrogen, HOxygen, ONitrogen, N Carbohydrate ✓✓✓✗ Lipid ✓✓✓✗ Protein ✓✓✓✓

8. Structure of carbohydrates, proteins and lipids 2.6 describe the structure of carbohydrates, proteins and lipids as large molecules made up from smaller basic units : starch and glycogen from simple sugar; protein from amino acids; lipid from fatty acids and glycerol

9. Tests for glucose and starch 2.7 describe the tests for glucose and starch  Starch: iodine solution turns from yellow-brown to blue-black  Glucose: Benedict’s solution turns from blue to brick red (through green, yellow and orange)

10. Enzymes: biological catalysts speed up reactions 2.8 understand the role of enzymes as biological catalysts in metabolic reactions

11. Enzymes: biological catalysts speed up reactions (2) 2.8 understand the role of enzymes as biological catalysts in metabolic reactions

12. Enzymes: effect of temperature 2.9 understand how the functioning of enzymes can be affected by changes in temperature, including changes due to change in active site. Above optimum temperature: enzyme denatured so active site does not fit substrate does not catalyse  reactions any more Below optimum temperature: too little kinetic energy  too few collisions between enzyme and substrate

13. Enzymes: effect of pH 2.10 understand how the functioning of enzymes can be affected by changes in active site caused by changes in pH This is just an example: The optimum pH in the stomach is not 8, but 3!

14. Enzyme activity and temperature experiment 2.11 describe experiments to investigate how enzyme activity can be affected by changes in temperature.

15. Balanced Diet 2.23 understand that a balanced diet should include appropriate proportions of carbohydrate, protein, lipid, vitamins, minerals, water and dietary fibre(TA) A diet that contains adequate amounts of all the necessary nutrients required for healthy growth & activity.

16. Balanced Diet 2.23 understand that a balanced diet should include appropriate proportions of carbohydrate, protein, lipid, vitamins, minerals, water and dietary fibre(TA)

17. 72% of our body is WATER. We contain so much water because water: Transports nutrients to cells, such as minerals, vitamins and glucose as part of our blood Part of urine and faeces, which removes waste from our body Is needed for sweat (essential in controlling our body temperature) Balanced Diet 2.23 understand that a balanced diet should include appropriate proportions of carbohydrate, protein, lipid, vitamins, minerals, water and dietary fibre(TA)

18. What do you have to eat 2.24 identify sources and describe functions of carbohydrate, protein, lipid (fats and oils), vitamins A, C and D, and the mineral ions calcium and iron, water and dietary fibre as components of the diet ComponentFunctionExample of sources CarbohydrateShort-term chemical energyBread, potatoes, rice, pasta Lipids (fats and oils)Long-term chemical energyMeat, cheese, eggs ProteinGrowth & repairFish, egg Vitamin AEyesightCarrots, fish liver oil Vitamin CHealthy skin + gumsOranges Vitamin DAbsorb CalciumSunlight, milk Mineral ions – Fe (iron)Making haemoglobin in RBCSpinach, red meat Mineral ions – Ca (calcium)Strong bones and teethmilk Dietary fiberPeristalsis; prevent constipationVegetables, cereal WaterTransport system To sweat All chemical reactions occur in water in cytoplasm Not just drinks; also fruits like watermelon

19. Not all bodies are Energy (J) Equal 2.25 understand that energy requirements vary with activity levels, age and pregnancy (TA) PersonEnergy needed per day (kJ) Newborn baby2000 Age 25000 Age 67500 Girl age 12-149000 Boy age 12-1411000 Girl age 15-179000 Boy age 15-1712000 Female office worker9500 Male office worker10500 Heavy manual worker15000 Pregnant woman10000 Breast-feeding woman11300

20. Energy requirements vary according to several factors: Age: growing people require more energy than others. Gender: on average, males require more energy than females. Pregnancy: pregnant women require more energy to nourish themselves and the baby. Activity levels: more active people require more energy as they use up more energy throughout the day. Bodies use different amounts of energy 2.25 understand that energy requirements vary with activity levels, age and pregnancy (TA)

21. Name that structure 2.26 describe the structures of the human alimentary canal and describe the functions of the mouth, oesophagus, stomach, small intestine, large intestine and pancreas game

22. Describe the function 2.26 describe the structures of the human alimentary canal and describe the functions of the mouth, oesophagus, stomach, small intestine, large intestine and pancreas Functions Mouth Teeth chew & grind to increase surface area Salivary glands produce saliva -> moistens food, making it easier to swallow Chemical digestion by amylase breaks down starch into maltose Oesophagus Food is moved by peristalsis Stomach Produces acid: HCl (kills bacteria) Produces protease (pepsin) enzymes Churns food to increase surface area Small intestine Produces carbohydrase (maltase) and protease (trypsin) Absorbs digested food Pancreas Produces carbohydrase (amylase), protease (trypsin) & lipase enzymes Large intestine Absorbs water Rectum / anus Stores faeces / opens so egestion can happen

23. Flow Chart of Nutrition and Digestion 2.27 understand the processes of ingestion, digestion, absorption, assimilation and egestion Ingestion Taking food into the body Digestion The breakdown of large insoluble molecules into small soluble molecules so they can be absorbed into the blood Absorption The process of absorbing nutrients into the body after digestion Assimilation Using food molecules to build new molecules Egestion Getting rid of undigested/unwan ted food

24. Flow Chart of Nutrition and Digestion 2.27 understand the processes of ingestion, digestion, absorption, assimilation and egestion Digestion can be mechanical or chemical Mechanical Digestion: digestion by physically breaking food into smaller pieces (i.e. not using enzymes) to make it easy to move and increase the surface area. Carried out by: mouth and teeth chewing food stomach churning food Chemical Digestion: digestion using enzymes Where it is made Where it worksEnzyme SubstrateProducts Salivary GlandsMouthAmylaseStarchMaltose Stomach cellsStomachProteaseProteinAmino Acids LiverSmall IntestineBile SaltsFatFat droplets Pancreas Small Intestine Amylase Protease Lipase Starch Protein Lipids Maltose Amino Acids Glycerol & Fatty acids Small Intestine Maltase Protease Maltose Protein Glucose Amino Acids

25. Peristalsis 2.28 explain how and why food is moved through the gut by peristalsis Food is moved the digestive system by a process known as peristalsis. This is the contraction of two sets of muscles in the walls of the gut. 1)One set runs along the gut 2)The other set circles it. Their wave-like contractions create a squeezing action, moving down the gut.

26. Digestive Enzymes 2.29 understand the role of digestive enzymes, to include the digestion of starch to glucose by amylase and maltase, the digestion of proteins to amino acids by proteases and the digestion of lipids to fatty acids and glycerol by lipases Enzymes involved in respiration and making new molecules work inside cells. Digestive enzymes are produced and released by specialised cells and work outside the cells. Different enzymes (Different enzymes catalyse different digestion reactions)

27. Digestive Enzymes 2.29 understand the role of digestive enzymes, to include the digestion of starch to glucose by amylase and maltase, the digestion of proteins to amino acids by proteases

28. Digestive Enzymes 2.29 understand the role of digestive enzymes, to include the digestion of lipids to fatty acids and glycerol by lipases

29. Bile starts the digestion of lipids 2.30 understand that bile is produced by the liver and stored in the gall bladder, and understand the role of bile in neutralising stomach acid and emulsifying lipids After the stomach, food travels to the small intestine. The enzymes in the small intestine work best in alkaline conditions, but the food is acidic after being in the stomach. Bile alkaline so it neutralizes stomach acid Bile is produced by the liver and stored in the gall bladder. Bile is secreted into the small intestine, where it emulsifies (splits up fats) Splitting fats increases the surface area for lipases to work.

30. Absorption in the small intestine 2.31 describe the structure of a villus and explain how this helps absorption of the products of digestion in the small intestine Absorption in the small intestine 2.31 describe the structure of a villus and explain how this helps absorption of the products of digestion in the small intestine

32. The villus 2.31 describe the structure of a villus and explain how this helps absorption of the products of digestion in the small intestine Where small soluble nutrients are absorbed into the blood. AdaptationExplanation Thin wallWall of villus is 1 cell thick, which speeds the rate of diffusion of molecules into the blood Rich blood supplyAbsorbed molecules are carried away fast. So there is a low concentration of food molecules in the blood, which maintains a high concentration gradient Intestine lengthRoughly 7m long, which increases the surface area Surface Area Villi and microvilli increase the surface area of the small intestine by 1000x

33. How much energy is in that peanut? 2.32 describe an experiment to investigate the energy content in a food sample.(TA) There are problems with using this set-up: Not all the food burns Water loses heat to environment