1. OCR AS Biology – F212 – Module 2 Food & Health

2. (e) explain that humans depend on plants for food as they are the basis of all food chains. (No details of food chains are required)  Humans are dependent on plants as they are the basis for all food chains

3. (f) outline how selective breeding is used to produce crop plants with high yields, disease resistance and pest resistance (g) outline how selective breeding is used to produce domestic animals with high productivity  Chose organisms with characteristic you want, breed together individuals with that characteristics, repeat  E.g. Crops with high yield, disease resistance and pest resistance  E.g. domestic animals with high productivity

4. (h) describe how the use of fertilisers and pesticides with plants and the use of antibiotics with animals can increase food production  Use of fertilisers and pesticides (plants) Fertilisers: provide minerals for growth Pesticides: kill pests that feed on crop, reducing amount of plants damaged/destroyed  Use of antibiotics (animals) Don’t waste energy fighting disease Promote growth by affecting bacteria in gut Increase the size of animals when mature

5. Questions 1) Explain how food production can be increased with the use of pesticides 2) Briefly describe how selective breeding is used to increase food production 3) Give 2 advantages of using selective breeding

6. Answers 1) Explain how food production can be increased with the use of pesticides Kills pests Less plants destroyed Increased yield 2) Briefly describe how selective breeding is used to increase food production Select organisms with useful characteristics to increase food production Breed together Select offspring with best characteristics Breed together Repeat 3) Give 2 advantages of using selective breeding Produce high yielding animals/plants Produce organisms with increased resistance to disease so need to use less pesticides/antibiotics Increased tolerance to poor conditions

7. Learning ObjectivesSuccess Criteria  Understand that food spoilage can be harmful to human health.  Understand the methods used to prevent food spoilage.  Understand how microorganisms can be used to make food.  Discuss the advantages and disadvantages of using microorganisms.  Recall the ways in which food spoilage can be seen (E-D)  Describe the ways in which food spoilage can be prevented (C-B).  Explain how microorganisms can be used to make food and the advantages/disadvantag es of this (A-A*)

8. Starter  If a nuclear holocaust was imminent, what kind of food would you stock in your bomb shelter to last you through the next few months? Canned FoodDry CerealsPickled Food Dried/ Salted Snacks Smoked Food

9. Food Spoilage  How do we know food is spoilt?  For example, meat left out for a while may be covered in harmful bacteria.  The meat may look fine to eat, but consumption could cause major illness. The signs of food spoilage are not always immediately visible.

10. Food Spoilage – Visible Growth  Moulds are the most obvious visible form of microorganism on our food.  Fungi like the ones above feed saprophytically.  This means they secrete enzymes onto food and then absorb the products into their cells. Mucor fungus on bread. An orange covered in Penicillium fungus

11. Food Spoilage – Toxins  Some microorganisms release toxins onto our food.  This can cause serious illness, especially in the case of Clostridium botulinium.  This bacteria releases botulin, of which as little as 1µg can kill a person. C. botulinium causes the disease, botulism.

12. Food Spoilage – Infection  A very common problem caused by eating spoilt food is infection.  Salmonella bacteria is associated with poultry (both meat & eggs).  The bacteria attack the lining of the stomach and intestine.

14. Preventing Food Spoilage  Use the bottom half of page 158 to find out how fresh food can be saved from spoilage. MethodHow it works... Salting Adding sugar Pickling Cooling/Freezing Heat Treatment Irradiation Drying

15. (j) outline how salting, adding sugar, pickling, freezing, heat treatment and irradiation can be used to prevent food spoilage by microorganisms  Bacteria break down food by releasing enzymes and breaking down molecules into their component parts  Drying/Salting – dehydrate microorganisms  Adding Sugar – dehydrate microorganisms  Pickling – pH kills microorganisms  Freezing – slow growth  Heat Treatment – denatures enzymes  Irradiation – disrupts DNA

17. Microorganisms in Making Food  Microorganisms aren’t all bad – they can be used to make food too. Yoghurt Lactobacillus uses lactose in milk to make lactic acid. The milk is partially digested by the bacteria. This makes it easy to digest for us. Cheese Milk is allowed to curdle. The solid, curdled milk is acted upon by Lactobacillus and additional flavours can be achieved by contamination with Penicillium. (e.g. Blue cheese)

18. Microorganisms in Making Food Bread Bread is made to rise by yeast. Yeast respires anaerobically, releasing carbon dioxide bubbles. These cause bread to rise. Alcohol Cereal grains contain the sugar maltose, which yeast respire upon. Alcohol is produced as a product of anaerobic respiration by the yeast. Cereals are replaced with grapes when making wine.

19. Quorn TM  A very well-known protein produced by a fungus is Mycoprotein.  This is the protein present in the meat-substitute food product known as Quorn.  Quorn is a very healthy option as it contains no animal fat or cholesterol, which as you now know can be harmful to health. The mycoprotein in Quorn is made by the fungus: Fusarium venenatum

20. Question 1) Describe an example of the use of microorganisms in food production 2) What is meant by the term ‘food spoilage’ 3) Describe how adding sugar to food can prevent spoilage 4) What is the name of the food preservation that involves exposing food to gamma or x rays?

21. Answers 1) Describe an example of the use of microorganisms in food production Bread making (yeast makes carbon dioxide) Wine making (yeast turns sugar into alcohol) Cheese making (bacteria curdles milk) Yoghurt (bacteria turn sugar into lactic acid) 2) What is meant by the term ‘food spoilage’ Deterioration of the food’s characteristic 3) Describe how adding sugar to food can prevent spoilage Inhibits growth of microorganisms By interfering with their water absorption 4) What is the name of the food preservation that involves exposing food to gamma or x rays? Irradiation

22. Think, Pair, Share

23. (i) describe the advantages and disadvantages of using microorganisms to make food for human consumption  Advantages Faster production of protein Increased/decreased on demand No animal welfare issues Source of protein for vegetarians  Disadvantages Not want to eat food grown on waste Protein needs to be isolated Could grow pathogenic organisms by accident Not taste or texture of traditional protein

24. Learning ObjectivesSuccess Criteria  Understand that food spoilage can be harmful to human health.  Understand the methods used to prevent food spoilage.  Understand how microorganisms can be used to make food.  Discuss the advantages and disadvantages of using microorganisms.  Recall the ways in which food spoilage can be seen (E-D)  Describe the ways in which food spoilage can be prevented (C-B).  Explain how microorganisms can be used to make food and the advantages/disadvantag es of this (A-A*)

25. Plenary

26. [3]  bacteria / (bacterial) cells, divide / increase in number / multiply / reproduce / proliferate / replicate ;  (secrete) enzymes / named enzyme ;  food, digested / broken down ;  protein / named protein / polypeptides → peptides / amino acids OR fat / triglycerides → fatty acids OR starch / amylose / glycogen → glucose / sugar ;  production / release / excretion / secretion, of, toxins / named toxin / waste products ;  (causes) change in, appearance / smell / texture / taste ;

27. [3]  bacteria, reproduce / AW, more rapidly / faster ;  (so) more bacteria present ;  more, toxins / waste, produced / released / AW  more enzymes, secreted / AW ;  enzyme, action faster / works better / more effective, at higher temperatures ;  (substrate and enzymes have) more kinetic energy ;  more, enzyme-substrate complexes / ESC / (successful) collisions between substrate and active site ;

28. [4]  salting ; lack of water due to, osmosis / low water potential (outside cell) ;  sugar ; lack of water due to, osmosis / low water potential (outside cell) ;  (air / freeze) drying ; idea that enzymes cannot mobilise / intracellular transport impaired / reactions have no medium in which to occur / (microbes) cannot move ;  pickling / (use of) vinegar ; (low pH) denatures / changes tertiary structure of / changes 3D shape of, enzymes / proteins substrate no longer fits active site / active site shape changes / prevents ESC ;  heat treatment / cooking ; denatures / changes tertiary structure of / changes 3D shape of, enzymes / proteins substrate no longer fits active site / active site shape changes / prevents ESC ;  irradiation / UV / gamma rays / X-rays / ionising radiation ; destroys / damages / changes / mutates, DNA / genes / genetic material ;