1. UNIT 1: Cell Biology
Respiration

2. Energy release

3. Energy release Learning intention:
State that living organisms need energy for many activities and that energy is released from food molecules.
Why?
Each cell requires energy for a huge range of processes and it is important to know where this energy comes from.

4. Energy release
The energy released in respiration can be shown by the custard bomb and the screaming jelly baby experiments.

5. Complete Practical 1in the booklet.
Watch the video of the screaming jelly baby.
screaming jelly baby

6. Food and energy
In this topic we will be investigating how energy is released from food molecules inside cells.
Organisms need energy for lots of different activities:
muscle contraction
cell division
synthesis of proteins
transmission of nerve impulses

7. Food and energy
We are going to investigate the energy content of food.
What type of energy is stored in food?
We can burn food and convert the chemical energy into heat energy.
Different foods contain different quantities of energy.

8. Food and energy
We are going to investigate the three main classes of food:
Protein
Carbohydrate
Fat
Which type of food would you expect to contain the most energy?

9. Measuring the energy content of food
Heat energy is measured in joules (j) or kilojoules (kJ).
It takes 4.2j to raise the temperature of 1000g of water by 1ºC.

10. Complete practical 2 in the booklet.
Complete the what to do section under the energy release title in the booklet. .

11. Measuring the energy content of food
Heat is lost to the surroundings
Food may not burn completely
Flame is near bulb of the thermometer and may give a distorted reading

12. Measuring the energy content of food

13. What is respiration?

14. What is respiration? Learning intention:
State that respiration is the release of energy from food molecules.
Describe that molecules of ATP are made during respiration.
Why?
Each cell requires energy for a huge range of processes from contracting muscles to transmitting nerve impulses.

15. Adenosine triphosphate (ATP)
ATP is found in living cells.
To form ATP the cell uses some of the energy from respiration.
When the cell needs energy ATP can be broken down to release the stored energy.

16. Adenosine TriphosphatePi
3 inorganic phosphates

17. ATP is made in cells from ADP and inorganic phosphate (Pi)
Adenosine Pi Pi
2 inorganic phosphates

18. The role of ATP
The formation of ATP allows the cell to store the energy released from respiration.
The process of forming ATP uses energy from respiration to add an inorganic phosphate molecule to ADP.

19. Formation of ATP ENERGY Pi Adenosine Pi Pi Adenosine
The energy released when glucose is broken down is stored as ATP.
ENERGY Pi
Adenosine Pi
Adenosine Pi

20. The role of ATP
ATP molecules have a high level of chemical energy (stored energy).
If the cell needs energy it can breakdown ATP back into ADP and energy is released.
Enzymes carry out the breakdown of ATP to ADP.

21. Breakdown of ATP ENERGY Adenosine Pi Pi Adenosine Pi
The energy released when glucose is broken down is stored as ATP.
Adenosine Pi
Adenosine Pi Pi
ENERGY

23. ADP + Pi are now ready to…
Make more ATP!
ATP
Glucose
ENERGY
ENERGY
Cell activities
ADP + Pi

24. The role of ATP

25. The role of ATP
Muscle contraction
beating heart

26. The role of ATP
Cell division
mitosis

27. The role of ATP
Protein synthesis

28. The role of ATP
Transmission of nerve impulses
nerve impulse

29. The role of ATP
Movement of sperm cells
movement of sperm

30. The role of ATP
Action of companion cells

31. The role of ATP Muscle contraction Cell division Protein synthesis
Transmission of nerve impulses
Movement of sperm cells
Complete the what to do section under the ATP title in the booklet.

32. Glucose
ENERGY
ATP
ADP + Pi
Cell activities

33. Aerobic respiration

34. Aerobic respiration Learning intention:
Give the word equation for aerobic respiration
Describe the chemistry of respiration
Why?
Respiration is a very important process which provides ATP for cell activities.

35. Respiration
Respiration is the chemical process which releases energy from the food we eat.
Do not mix up breathing with respiration.
Breathing involves taking in oxygen and releasing carbon dioxide, whereas respiration is a chemical reaction.

36. Respiration
Respiration is a series of reactions which breakdown glucose and release energy a little at a time.
If all the energy stored in glucose was released at one time, this would damage the cell.
Therefore different enzymes carry out different stages of the breakdown.

37. Word equation glucose + oxygen → carbon dioxide + water + ENERGY
Raw materials
Products

38. Aerobic respiration
If oxygen is available in cells, aerobic respiration will take place.
In aerobic respiration oxygen is used up in the breakdown of glucose.
This is why living things must breathe in oxygen.

39. Glycolysis
The first stage of aerobic respiration in the breakdown of glucose into two molecules of pyruvate.
This reaction takes place by a series of enzyme controlled reactions.
Glycolysis does not require oxygen and produces 2 ATP.

40. Glycolysis
Respiration begins with each molecule of glucose being broken down to form 2 molecules of pyruvate.
2 molecules of ATP also produced for each glucose molecule broken down.
glucose
2 ADP + Pi
2 ATP
pyruvate
pyruvate

41. First stage in aerobic respiration
Complete the what to do section under the first stage in aerobic respiration title in the booklet.

42. The second stage of aerobic respiration
There is still a lot of energy in pyruvate, therefore it is further broken down.
During the second stage of respiration, pyruvate is broken down into carbon dioxide and water.
This stage releases a large amount of ATP.

43. Breakdown of pyruvate
The breakdown of pyruvate is also carried out by enzymes.
This stage occurs in the mitochondria and requires the presence of oxygen.
If oxygen is not available, the pyruvate cannot be broken down into carbon dioxide and water.

44. series of enzyme controlled reactions
Breakdown of pyruvate
pyruvate
+ oxygen
36 ADP + Pi
series of enzyme controlled reactions
36 ATP
carbon dioxide + water

45. pyruvate
CO 2
H 2
H 2O
18 ATP O2

46. Breakdown of pyruvate
Complete the what to do section under the second stage in aerobic respiration title in the booklet.

47. Respirometer Measures the rate of oxygen uptake by an organism.
Soda lime absorbs carbon dioxide.
Red dye moves up the tube.
Worm
Soda lime
Red dye

48. Respirometer
Your teacher will now demonstrate how to set up a respirometer.
Worm
Soda lime
Red dye
Complete the what to do section under the respirometer title in the booklet.

49. The great balloon race
Place 5ml of yeast suspension and 5ml of yeast suspension in a test tube.
Place a balloon over the mouth of the test tube.
Have a race!
balloon race

50. Enzymes and respiration

51. Enzymes and respiration
Learning intention:
I understand that enzymes control the reactions of respiration.
Why?
As the reactions of respiration are controlled by enzymes the rate will be affected by temperature.

52. Temperature and respiration
The reactions of respiration are controlled by enzymes.
How would you expect temperature to effect the rate of respiration?

53. You are going to investigate the effect of temperature on the rate of respiration in yeast cells.

54. You can use the indicator resazurin to measure the rate of respiration.
During respiration in yeast glucose is oxidised and hydrogen released at various stages
Resazurin dye changes colour when it is reduced(gains H2).
Blue pink colourless
no reduction partial reduction reduction
The faster the resazurin dye changes colour the faster the rate of respiration.

55. Complete Practical 3 under the temperature and respiration title in the booklet.

56. Anaerobic respiration in animals and bacteria

57. Anaerobic respiration in animals and bacteria
Learning intention:
Describe anaerobic respiration in animals and bacteria.
Why?
It is important to understand why you get muscle fatigue.

58. Anaerobic respiration
When oxygen is not available, anaerobic respiration (fermentation) takes place.
For fish, the water they live in may not contain enough dissolved oxygen.
The amount of oxygen in the blood can also be reduced if an animal is exercising vigorously and it cannot breathe fast enough to meet the demand.

59. Why wouldn’t oxygen be present?
Exercising hard

60. Anaerobic respiration
When oxygen is not present, glucose cannot be completely broken down into carbon dioxide and water.
Glycolysis occurs as normal and glucose is broken down into 2 molecules of pyruvate, releasing 2 ATP.
Because there is no oxygen, the pyruvate cannot be broken down.

61. If no oxygen is present…
Pyruvate won’t be broken down.
PYRUVATE

62. If no oxygen is available then this happens….
1 x GLUCOSE
2 ADP + Pi
2 ATP
Alternative Route
PYRUVATE

63. Anaerobic respiration in animals and bacteria
Glycolysis takes place, but without oxygen the pyruvate can’t be broken down any further.
PYRUVATE
LACTIC ACID
NO OXYGEN

64. Anaerobic respiration
glucose
2 ADP + Pi
2 ATP
pyruvate
lactic acid

65. Anaerobic respiration
During anaerobic respiration 2 ATP are released when glucose is broken down into pyruvate.
When pyruvate is broken down into lactic acid, 0 ATP are produced.
This means anaerobic respiration only produces 2 ATP in total.

66. Anaerobic respiration
Stage
Aerobic
Anaerobic
No of ATP molecules
Stage 1
Glycolysis 2
Stage 2
Breakdown of Pyruvate 36
Total 38

67. Effects of lactic acid on muscle cells
Normally, muscle cells have a plentiful supply of oxygen and respire aerobically.
If a person is carrying out gentle exercise, muscle cells usually get enough oxygen to respire aerobically.

68. Anaerobic respiration
During vigorous exercise, the breathing rate cannot supply the muscles cells with enough oxygen.
This means the muscle cells start to respire anaerobically.
This means lactic acid builds up in the muscle cells causing the muscle to ache.

69. Anaerobic respiration
When the anaerobic exercise stops, the muscles require a recovery period.
The breathing rate continues at a high level.
The oxygen taken in is used to convert the lactic acid back to pyruvate.
The volume of oxygen needed to do this is called the oxygen debt.

70. pyruvate lactic acid Without, oxygen, pyruvate forms lactic acidb
Without, oxygen, pyruvate forms lactic acid
pyruvate
OXYGEN DEBT
PAID
OXYGEN DEBT
lactic acid
Complete the what to do section under the anaerobic respiration in animals and bacteria title in the booklet.

71. Anaerobic respiration in plants and yeast

72. Anaerobic respiration in plants and yeast
Learning intention:
Describe anaerobic respiration in plants and yeast.
Why?
So you can appreciate the use of yeast in the biotechnological industries.

73. Anaerobic respiration
The first stage of anaerobic respiration occurs as normal for animals.
Glycolysis occurs and glucose is broken down into 2 molecules of pyruvate, releasing 2 ATP.
In plants and yeast, the pyruvate is broken down into carbon dioxide and ethanol.

74. Anaerobic respiration
Anaerobic respiration may occur in the root cells of plants if they are submerged in water.
Some industries use yeast to make certain products i.e. beer.

75. Anaerobic respiration in plants and yeast

76. Anaerobic respiration in plants and yeast
glucose
2 ADP + Pi
2 ATP
pyruvate
released
carbon dioxide and ethanol

77. Anaerobic respiration in plants and yeast
The second process of anaerobic respiration in plants and yeast releases 0 ATP.
This means only 2 ATP are produced in total.
The carbon dioxide is released from the plant as a gas, this means anaerobic respiration in plants and yeast is irreversible.

78. vacuum flask to reduce heat loss
thermometer
vacuum flask to reduce heat loss
oil layer
boiled and cooled glucose solution + live yeast cells
lime Water

79. vacuum flask to reduce heat loss
after 2 days
live yeast cells
thermometer
vacuum flask to reduce heat loss
oil layer
boiled and cooled glucose solution + live yeast cells
lime water cloudy

80. Anaerobic respiration in yeast
Test
Observation
At start
After 24 hours
Smell of a sample from the flask
yeasty
alcohol
Appearance of limewater
clear
cloudy (CO2 released)
Temperature of mixture in the flask
20°C
26°C
Complete the what to do section under the anaerobic respiration in plants and yeast title in the booklet.

81. Aerobic vs. anaerobic respiration
Complete the comparing aerobic and anaerobic respiration section of the booklet.

82. Comparing aerobic and anaerobic respiration

83. Comparing aerobic and anaerobic respiration
Learning intention:
Compare aerobic and anaerobic respiration.
Why?
It is important to understand that more ATP is released by aerobic respiration and that is why many organisms require oxygen.

84. carbon dioxide and water carbon dioxide and ethanol
glucose
2 ADP + Pi
2 ATP
oxygen present
pyruvate
no oxygen present - animals
36 ATP
no oxygen present – plants and yeast
36 ADP + Pi
lactic acid
carbon dioxide and water
oxygen debt
carbon dioxide and ethanol

85. Comparing aerobic and anaerobic respiration
Using books, your notes and the internet make a poster to compare aerobic and anaerobic respiration.
One half of the poster should detail aerobic and the other half anaerobic respiration.