2. Two types of Respiration
1 Internal / Cellular Aerobic
respiration
Anaerobic
Ventilation /
2 External breathing
respiration
Gaseous exchange

3. Cellular respiration is:
the series of chemical changes which release
energy from food material

4. Aerobic respiration
Balanced equation:
C6H12O6 + 6O2  6CO2 + 6H2O + energy
Word equation:
glucose + oxygen carbon + water + energy
dioxide

5. There is energy locked up in
each bond
Energy is released
when bonds
break
A glucose molecule Wastes
C6H12O6 CO2 & H2O

6. TWO forms of energy are
released from food:
1. ATP (adenosine triphosphate)
2. heat

7. ATP:
can be moved about inside a cell
is a store of energy inside cells
ADENOSINE

8. What do you conclude from this
experiment:
A drop of glucose A drop of ATP
solution is put on solution is put on
a muscle: a muscle:
nothing happens it contracts
Glucose by itself cannot provide the
energy but ATP can.

9. Respiration builds ATP
ADP + P + energy from → ATP
glucose
Adenosine Phosphate Adenosine
diphosphate triphosphate
energy
from
glucose

10. The body can use the energy released when
ATP is broken down:
energy able
ATP → ADP + P + to do work

11. Where do
aerobic & anaerobic
respiration occur?

12. Aerobic respiration occurs
inside mitochondria
Anaerobic respiration
occurs in the cytoplasm

13. muscle
contraction
Respiration
supplies
the energy for
transmission
of impulses
building proteins
in cells cell division

15. Which chemical is used to test
for CO2 as in exhaled air ?

16. Lime water turns milky

17. AIM: To find out if a person
breathes out CO2
BLOW

18. AIM: To show that respiration
produces heat.

19. RESULT:
Living seeds:
Temperature
rises
CONCLUSION:
The temperature rose because germinating pea
seeds release heat energy during respiration.

20. Important:
soda lime / lime water /
sodium hydroxide: calcium hydroxide:
Absorbs CO2 Tests for CO2

21. AIM: To show that animals
release CO2.
Bottle A: Bottle B:
Lime water Lime water

22. Result:
Bottle A:
Bottle B:
Lime water [colourless]
Lime water [milky]
Describe a suitable control for this
experiment.

23. Which one is correct as a control?
Dead mouse
Empty jar

24. Why is a dead mouse wrong as a
control?
Bacteria decompose the dead body
and release carbon dioxide.

25. AIM: To show that germinating
seeds release CO2.
What do you conclude if lime water in
Flask B becomes milky?

26. CO2 is present before air enters
jar with seeds.
What must be done to conduct the
experiment correctly ? Add soda lime.

27. AIM: To show that a green plant
releases carbon dioxide.

28. What is the control?
No
plant

29. RESULT:
Lime water A: Lime water B:
remains clear. turns milky.

30. CONCLUSION:
Since lime water A remained clear, this
indicates that all of the carbon dioxide
in the original incoming air had been
removed by the sodium hydroxide.
Since lime water B turned milky, shows
that carbon dioxide was produced by
the green plant during respiration.

32. Anaerobic respiration occurs
without the need of oxygen
in animals, plants and yeast
Yeast cell

33. Anaerobic respiration
glucose → lactic acid + energy
C6H12O6 2C3H6O3 + 150kJ
carbon
glucose → ethanol + carbon + energy
dioxide
C6H12O6 2C2H5OH + 2CO2 + 210 kJ

34. Why is aerobic respiration more
efficient than anaerobic respiration?
C6H12O6 + 6O2  6CO2 + 6H2O + 2830 kJ
C6H12O6 2C2H5OH + 2CO2 + 210 kJ
C6H12O6 2C3H6O3 + 150kJ

35. releases
than

36. Look at equations & fill in: Glucose is
completely broken down during…………..
aerobic
C6H12O6 + 6O2  6CO2 + 6H2O + 2830 kJ
C6H12O6 2C2H5OH + 2CO2 + 210 kJ
C6H12O6 2C3H6O3 + 150kJ

37. ANAEROBIC RESPIRATION
IN
ANIMALS

38. When does anaerobic respiration
occur in animals?
During heavy exercise

39. Why does it occur?
Muscles resort to anaerobic
respiration when oxygen is not
delivered to them fast enough.
I need 10 units of oxygen
BUT am getting 5 units!!

40. Lactic acid
is a mild poison and
causes the muscles to ache
causes:
 fatigue
 & sometimes cramps

41. Lactic acid is removed from
muscle by the bloodstream and is
glucose lactic
acid
Blood
CO2 lactic
H2O acid
broken down
Liver
in the liver

42. What is needed for lactic acid to
be broken down in the liver?

43. Oxygen debt:
is the oxygen needed to get rid of the
lactic acid
lactic acid + O
2
CO2 + H2O

44. Explain why:
After activity that has lead to anaerobic
respiration, the person involved pants
and breathes heavily.
To pay the oxygen debt.

45. ANAEROBIC RESPIRATION
IN
YEAST

46. Anaerobic respiration is also
called alcoholic fermentation
glucose → ethanol + carbon dioxide + energy
C6H12O6 → 2C2H5OH + 2CO2 + 210 kJ

47. Why has the balloon inflated?
Yeast & sugar in
warm water After 15 After 30
were poured into minutes.
a bottle. minutes.

48. AIM: To show anaerobic
respiration in yeast.

49. Test for CO2: limewater turns milky

50. How would you
modify the
apparatus to
keep a constant
temperature?
Place flask in a
water bath.

51. RESULT:
 Living yeast: The lime water turned milky.
 Boiled yeast: No colour change in the lime
water.
CONCLUSION:
 The living yeast respired anaerobically
and released carbon dioxide. This can be
concluded since the carbon dioxide turns
lime water (calcium hydroxide) cloudy.

52. If apparatus is left for many days, no
bubbles are given off. Give two
reasons.
1. No glucose
left.
2. Yeast died.

53. Question: SEP, 2012
A biology student compared the rates of
fermentation of glucose and sucrose
solutions using yeast. The student set up
the apparatus above using water instead of
limewater. The time to produce 10 gas
bubbles was recorded. The experimental
apparatus was first set up with glucose and
then repeated with sucrose.
i) What other apparatus would the
students need to obtain their results? (1)
A control.

54. Question: SEP, 2012
i) Identify the solution that would give a
faster rate of reaction and give ONE
reason for your answer. (4)
Glucose.
Monosaccharide which is used right
away. Sucrose is a disaccharide and
must be first broken down into
monsaccharides before used for
respiration.

55. Question: SEP, 2010
Give a biological explanation for each of
the following statements:
Lactic acid builds up in muscle cells after
heavy exercise. (4)

56. Question: SEP, 2011
Give a biological explanation for each of
the following statements:
The rate and depth of breathing change
during and after exercise. (5)

57. DIFFERENCES BETWEEN
AEROBIC & ANAEROBIC
RESPIRATION

58. Aerobic respiration Anaerobic respiration
1) More energy is released Less energy is released
2) Needs oxygen Oxygen is not needed
3) Occurs inside
Occurs in the cytoplasm
mitochondria
4) Glucose is completely Glucose is partially broken
broken down down
5) CO2 and H2O are the Wastes in yeast:
waste materials CO2 & ethanol
Waste in animals:
lactic acid

59. List four ways in which respiration differs
from photosynthesis.

60. Respiration Photosynthesis
1. Occurs all the time. 1. Occurs only in light.
2. Occurs in all 2. Occurs in green
organisms. plants.
3. Releases carbon 3. Releases oxygen
dioxide.
4. Uses food. 4. Builds food.

61. THE END It’s great to be
energetic – I can
study all day
long!!!