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. Starting temperature of water (0C)
Results
Food Material
Mass of food
(g)
Starting temperature of water (0C)
Finishing temperature of water
(0C)
Temperature rise (0C)
Carbohydrate
Protein
Fat

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. Structure of ATP
adenosine Pi

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 adenosine Pi Enzymes Energy from respiration
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
ATP
Enzymes Pi
adenosine +
ADP
Energy released to do work

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

22. 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
glyco lysis
glucose splitting

25. Glycolysis does not require oxygen
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 presence of oxygen.

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. Steps of aerobic respiration
A. glycolysis (glucose is split into 2 pyruvic acid, takes place in cytoplasm, also the 1st step of anaerobic respiration)
B. Krebs cycle (mitochondria)
C. oxidative phosphorylation or electron transport chain (the most ATP release, mitochondria)

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

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

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

33. Steps in anaerobic respiration in animals
1. glycolysis
2. lactic acid fermentation

34. in absence of oxygen pyruvic acid is turned into lactic acid.
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

35. A build up of lactic acid produces muscle fatigue
A build up of lactic acid produces muscle fatigue. 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 oxygen debt.

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

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

38. ethanol + carbon dioxide
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

39. 1. glycolysis
2. alcohol (ethanol) fermentation

40. Comparison of aerobic and anaerobic respiration
in animals
in plants and yeast
Oxygen required?
yes no
Glycolysis occurs
ATP yield
38ATP
2ATP
Glucose completely broke down?
End products
Carbon dioxide and water
Lactic acid
Ethanol and carbon dioxide

41. 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 of your textbook will help you with these tasks if you are finding it difficult to find information on the internet].

43. This powerpoint was kindly donated to 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.