Key area 7

1. Key area 7 Respiration

2. Energy In Our Food Learning Intention: To know the importance of food. Success Criteria: Be able to state the type of energy stored in food. Be able to describe how we measure the energy content in food.

3. Why do we need food? • Our body needs food to give us energy for movement, heat production and growth. • Food is also needed to keep us healthy. • The type of energy stored in food is chemical energy . • When food is burned, the chemical energy is changed into heat energy. • The units used to measure the energy in food are called kilojoules.

4. Why do we need food? Video Link

5. Activity 1 • Collect one food label. • Look at the ‘Nutritional Information’ and look for ‘Energy per 100g’. • Complete the table on the next slide. • Do the same for three more foods. • If you have time, choose one more food to do. • Draw a bar graph of your results.

6. Energy content of food

7. Energy in food • The energy we get from our food allows us to carry out everyday functions. • Some people need more energy than others.

8. Think about energy Answer the following questions: • What might affect the amount of energy a person needs in a day? • What would happen to your body if you took in more energy from your food than you need? • What would happen to your body if you didn’t get enough energy from your food to carry out your daily functions?

9. Energy in food • We can measure the energy in food by measuring the heat it produces when it is burned. • Your teacher will show you how to use this special spoon to burn the food. • You will test three different types of food – carbohydrate, protein and fat. Deflagrating spoon

10. Activity 2 - Burning food Here is the method you will use. Listen carefully to your teacher’s instructions. Wear safety goggles! Do not play with fire! thermometer boiling tube with 40ml cold water Deflagrating spoon Set fire to food in a bunsen burner, then quickly place spoon under boiling tube. Hold steady until the flame goes out. Clamp stand One level spoonful of burning food

11. Activity 2 • Now carry out the experiment and record your results. • Complete the conclusion for your experiment.

12. Respiration Learning Intention: Know what respiration is and why we need it. Success Criteria: Be able to describe the process of respiration. Be able to state the summary equation for respiration with oxygen. Be able to distinguish between the raw materials and products of respiration with oxygen.

13. Starter Activity: Answer the following questions Why do we need food? What type of energy is stored in food? What type of energy is this converted to when food is burned? What units are used to measure the energy in food?

14. What is respiration? • The chemical process by which energy is released in cells is called respiration. • It happens in all living cells, all of the time. • The main food source of energy for respiration in cells is glucose . • This process is controlled by enzymes. • Respiration can be carried out either with oxygen or without oxygen.

15. Watch and Listen • Video Clip

16. Who needs respiration? • Every living cell needs to carry out respiration. • This includes plants, animals, bacteria and yeast. • Cells can carry out respiration with or without oxygen. • First we will look at respiration WITH oxygen.

17. Respiration with oxygen Carbon dioxide Glucose water Oxygen ENERGY is produced for heat, movement etc. Human cells get their glucose and oxygen from the blood. They also release the carbon dioxide and water back into the blood. A human cell

18. Respiration with oxygen • The raw materials are glucose and oxygen. • Glucose contains a store of energy. • Glucose is broken down with the help of oxygen. • The end products are carbon dioxide and water. These are released from the cell. • This process produces lots ofenergy!

19. Respiration with oxygen • The following word equation summarises respiration with oxygen in cells: Glucose + Oxygen Energy + Carbon Dioxide + Water RawMaterials Products

20. Rate of Respiration Learning Intention: Know how the rate of respiration is affected. Success Criteria: Be able to name the three limiting factors that affect the rate of respiration. Be able to describe the effect a limiting factor has on the rate of respiration. Carry out an investigation into one of these limiting factors.

21. Rate of Respiration • How quickly our cells respire can be determined by several different factors. • These are called limiting factors. • This is because they can limit (slow down) the rate of respiration.

22. Limiting factors in respiration Carbon dioxide Glucose water Oxygen ENERGY is produced for heat, movement etc. Glucose and oxygen are both needed for respiration. If one of these is in short supply, respiration rate will decrease or respiration may stop altogether. A human cell

23. Limiting Factors • Oxygen concentration can limit the rate of respiration. • Glucose concentration can limit the rate of respiration. • Temperature can also limit the rate of respiration. This is because respiration is controlled by enzymes, and temperature affects how fast the enzymes work.

24. Limiting factors • As the glucose concentration increases, the respiration rate increases. • As the oxygen concentration increases, the respiration rate also increases. • Low glucose or oxygen concentration would result in low respiration rate. Glucose concentration Oxygen concentration

25. Temperature and respiration rate • A low temperature - 10°C for example – would result in a low rate of respiration.

26. Starter On a show me board, write down three limiting factors that affect the rate of respiration.

27. Respiration Investigation Learning Intention: Carrying out a investigation to find out the affect of limiting factors on germinating seeds. Success Criteria: Be able to write up an aim and method of how to carry out an investigation. Be able to carry out the investigation in a safe and responsible manner.

28. Respiration Investigation • You will carry out an investigation on the effects of limiting factors on germinating (starting to grow) seeds. • In order to germinate, seeds need energy from respiration. • If any requirements for respiration are in short supply, the seeds will not be able to germinate properly.

29. Discussion • You will investigate how your chosen factor affects the germination of seeds. • Your teacher will lead a class discussion to find out all of your ideas on how to carry out this investigation. • You will discuss the apparatus you will use and the safety precautions you will take.

30. Writing Up an Investigation You will complete an investigation report which will include the following sections: • Aim • Hypothesis • Diagram of apparatus • Method • Results table • Conclusion Respiration investigation flipchart

31. Results table

32. Respiration Investigation Learning Intention: Carrying out a investigation to find out the affect of limiting factors on germinating peas. Success Criteria: Be able to write up an aim and method of how to carry out an investigation. Be able to carry out the investigation in a safe and responsible manner.

33. Appropriate Clip art to topic Respiration Without Oxygen Learning Intention: To state the two pathways of respiration without oxygen. Success Criteria: Be able to describe the conditions that animals, plants and yeast would be in to carry out respiration without oxygen. Be able to write summary equations for respiration without oxygen in plant and yeast cells and in animal cells.

34. Watch and Listen • Video Clip

35. Respiration Without Oxygen • Sometimes the conditions a plant is growing in means that there is very little, or sometimes no oxygen available to the plant. • They still must carry out respiration .

36. Respiration without oxygen Carbon dioxide Glucose Alcohol A little ENERGY is produced Yeast cells get their glucose from their surroundings. They also release the carbon dioxide and alcohol back into the surroundings. A yeast cell

37. Respiration without oxygen • In yeast and plant cells, the raw material is glucose. • The products are carbon dioxide and alcohol. • This process produces only a little energy. • Respiration without oxygen in plants is called fermentation.

38. Respiration without oxygen • The following equation summarises respiration without oxygen in yeast and plant cells: Glucose Carbon Dioxide + Alcohol + A little energy Products Raw Material

39. Respiration Without Oxygen • Sometimes animal cells can have a low supply of oxygen, for example if a human is taking part in vigorous exercise. • The cells still carry out respiration.

40. Respiration without oxygen Lactic acid Glucose A little ENERGY is produced Muscle cells sometimes have to respire without oxygen. This causes lactic acid to build up inside the muscle cells. Your teacher will show you how to demonstrate this. A human cell

41. Respiration without oxygen • Respiration without oxygen in animal cells uses glucose as the raw material. • The product is lactic acid. • There is very little energy produced in this process. • Respiration without oxygen in animals is also called fermentation.

42. Respiration without oxygen • The following equation summarises respiration without oxygen in animal cells: Glucose Lactic Acid + A littleenergy Raw Material Products

43. Appropriate Clip art to topic Respiration Without Oxygen Learning Intention: To state the two pathways of respiration without oxygen. Success Criteria: Be able to describe the conditions that animals, plants and yeast would be in to carry out respiration without oxygen. Be able to write summary equations for respiration without oxygen in plant and yeast cells and in animal cells.