Respiration

1. Respiration

2. Custard powder experiment • Did the food contain energy? • What kind of energy did it have to start with? • What kinds of energy was this released as?

4. Comparing energy in carbohydrates,proteins and fats Use different types of food to calculate which will give the most energy

5. Results

6. Calculating energy in food • A given amount of any substance always requires the same amount of energy to produce a particular increase in temperature. • 1000g of water needs………………..4.2 kJ to make its temperature rise by 1 oC

7. Calculating the energy content of foods • The formula to calculate the energy release is • 4.2 x M x T • Now calculate the energy content of your foods M = mass of water (g) T=rise in temperature ( °C) 1000

8. Calorimeter

9. Gases and respiration • A: Living Peas B: Dead Peas • Burn a lighted splint in each gas jar.

10. Do other organisms respire? breathing and respiration

11. 1 Which type of energy does food contain? 2 What is this energy converted to by other organisms? Give at least 3 examples. (i) (ii) (iii) 3 What name is given to the process by which organisms release energy? 4 What kind of energy is always released in respiration?

12. The Chemistry of Respiration energy and mitochondria clip

13. Adenosine triphosphate • The energy released during respiration is not used directly by cells. • Instead it is used to make a molecule called ATP which stores the energy until it is needed. ATP = Adenosine triphosphate

14. What does ATP do? • ATP supplies energy for all the processes that need it. • For example: • movement • chemical reactions • growth. slow twitch/fast twitch investigation

15. adenosine Pi Pi Pi Structure of ATP

16. Formation of ATP ATP is made when another molecule called adenosine diphosphate (ADP) is bonded to a third inorganic phosphate (Pi) using the energy released from glucose.

17. adenosine Pi Pi + Pi adenosine Pi Pi Pi Energy from respiration Enzymes Energy Rich bond formed

18. Summarised as: ADP + Pi ATP The whole process is under the control of enzymes

19. The role of ATP • ATP stores the energy in the third bond of the molecule • The energy is released when that bond is broken to release the third inorganic phosphate (Pi) .

20. adenosine Pi Pi + Pi adenosine Pi Pi Pi ATP Enzymes ADP Energy released to do work

21. ATP ATP energy (in) energy (out) energy (out) cellular respiration cellular respiration cell activities cell activities ADP + Pi Summary The whole process is an enzyme controlled reaction.

22. Aerobic Respiration Aerobic respiration = respiration with oxygen.

23. glucose + OXYGEN energy + carbon dioxide + water(to make ATP)

24. Aerobic respiration happens in 2 stages: Stage 1 – Glycolysis glycolysis glucose splitting

25. In glycolysis, a glucose molecule is broken down into pyruvic acid. glucose series of enzyme controlled reactions energy released to make small quantity of ATP (2 molecules) pyruvic acid Glycolysis does not require oxygen

26. Stage 2 – Breakdown of pyruvic acid The pyruvic acid made in glycolysis (stage1) still contains a lot of energy It can only be broken down to release the rest of the energy in the presenceofoxygen.

27. pyruvic acid energy released to make large quantity of ATP (36 molecules) series of enzyme controlled reactions carbon dioxide + water

28. ATP production – summary glucose 2 ADP + 2 Pi = 2 ATP pyruvic acid 36 ADP + 36 Pi = 36 ATP carbon dioxide + water

29. Summary of ATP production • Stage 1 and 2 release all the chemical energy in one molecule of glucose to make a total of 38ATP molecules. 2 molecules ATP from glucose  pyruvic acid 36 molecules ATP from pyruvic acid  carbon- dioxide +water Total 38 molecules ATP

30. Anaerobic Respiration(in animals) anaerobic = in the absence of oxygen

31. In low oxygen conditions or during heavy exercise, when not enough oxygen can be supplied, muscle cells swap to anaerobicrespiration

32. glucose glycolysis still happens as it does not require oxygen 2 ADP + 2 Pi 2 ATP pyruvic acid in absence of oxygen pyruvic acid is turned into lactic acid. lactic acid

33. A build up of lactic acid produces musclefatigue. Muscle fatigue makes muscles ache and contract less powerfully.A recovery period is needed. During this time more oxygen is taken in to convert the lactic acid back into pyruvic acid again.The volume of oxygen needed is called the oxygendebt.

34. Summary glucose pyruvic acid oxygen debt e.g. during hard exercise oxygen debt repaid during recovery time lactic acid

35. Anaerobic Respiration in plants The same process occurs in plants and yeast in low oxygen conditions, e.g. muddy, flooded soils.

36. glucose pyruvic acid 2 ADP + 2 Pi 2 ATP glycolysis still happens, producing 2 ATP molecules This time in absence of oxygen, pyruvic acid is turned into carbon dioxide and ethanol This is irreversible ethanol + carbon dioxide

37. Comparison of aerobic and anaerobic respiration

38. Task • Prepare a series of PowerPoint slides which show the importance of anaerobic respiration in the brewing and bread-making processes. • Prepare a couple of slides to show the role of anaerobic respiration in the production of cheese and yogurt. [Pages 4 -14 of your textbook will help you with these tasks if you are finding it difficult to find information on the internet].

39. This powerpoint was kindly donated to www.worldofteaching.com http://www.worldofteaching.com is home to over a thousand powerpoints submitted by teachers. This is a completely free site and requires no registration. Please visit and I hope it will help in your teaching.