1
Think about…
22.1 Basic concepts of respiration
22.2 Site of respiration
22.3 Aerobic respiration
22.4 Anaerobic respiration
22.5 Relationship between respiration
and photosynthesis
Recall ‘Think about…’
Summary concept map
2
Food like corn can provide energy for
the body.
3
The sugar in it can also undergo
fermentation (發酵) to produce an alcohol.
4
The alcohol can be used as a fuel to
power vehicles.
5
This ‘biofuel’ (生物燃料) releases less
air pollutants upon burning.
6
1
How does our body
obtain energy from the
food we eat
7
2
How is alcohol
produced from corn
by fermentation
8
3
The sugar in corn is
made by photosynthesis.
What is the relationship
between respiration and
photosynthesis
9
22.1 Basic concepts of
respiration
What is respiration?
10
22.1 Basic concepts of respiration
What is respiration?
• when food is burnt, it reacts with oxygen
(oxidation 氧化):
heat
O2
light
CO2 + H2O
glucose
11
22.1 Basic concepts of respiration
What is respiration?
• when food is burnt, it reacts with oxygen
(oxidation 氧化):
- one step reaction
- takes place anywhere
- no enzyme involved
- fast and violent reaction
12
22.1 Basic concepts of respiration
What is respiration?
• when food is burnt, it reacts with oxygen
(oxidation 氧化):
- all stored energy is released at once
- energy is released in the forms of heat
and light
13
22.1 Basic concepts of respiration
What is respiration?
• the large amount of heat released in
burning kills living cells
 organisms undergo
respiration (呼吸作用)
the process by which organisms release
energy from food through the controlled
oxidative breakdown of food
14
22.1 Basic concepts of respiration
What is respiration?
• glucose is the most common substrate
heat
ATP
O2
CO2 + H2O
glucose
(in the cell)
15
22.1 Basic concepts of respiration
What is respiration?
• respiration:
- a series of reactions
- takes place in all living cells all the time
- controlled by many enzymes
- slow and gradual reactions
16
22.1 Basic concepts of respiration
What is respiration?
• respiration:
- stored energy is released gradually
- energy released is used to form ATP
while some is lost as heat
17
22.1 Basic concepts of respiration
What is respiration?
• overall equation:
glucose
CO2
O2
enzymes
H2O
energy
18
22.1 Basic concepts of respiration
What is the role of ATP?
• as energy carrier
energy
released
from
respiration
ATP
phosphorylation
(磷酸化)
P
ADP
19
22.1 Basic concepts of respiration
What is the role of ATP?
• as energy carrier
energy
released
from
respiration
releases
energy
to cells
ATP
breakdown
ADP
P
20
22.1 Basic concepts of respiration
What is the role of ATP?
• ATP releases energy for metabolic
activities:
- cell division
- muscle contraction
- transmission of
nerve impulse
21
22.1 Basic concepts of respiration
What is the role of ATP?
• ATP releases energy for metabolic
activities:
- synthesis of biomolecules
amino acids
protein
- absorption of food molecules or
minerals by active transport
22
22.1 Basic concepts of respiration
Types of respiration
1 Aerobic respiration (需氧呼吸)
• requires oxygen
• glucose is completely broken down
• a large amount of energy is released
23
22.1 Basic concepts of respiration
Types of respiration
2 Anaerobic respiration (缺氧呼吸)
• does not require oxygen
• glucose is only partly broken down
• much less energy is released
• products are different from aerobic
respiration
24
22.1 Basic concepts of respiration
1 Respiration is the process by which
organisms release chemical
energy from food through the
controlled oxidative breakdown of
food .
25
22.1 Basic concepts of respiration
2a Similarities between burning
and respiration:
i Both are an oxidative process.
26
22.1 Basic concepts of respiration
2a Similarities between burning
and respiration:
ii Both need oxygen .
27
22.1 Basic concepts of respiration
2a Similarities between burning
and respiration:
iii Carbon dioxide and water are
produced.
28
22.1 Basic concepts of respiration
2b Differences between burning
and respiration:
i Burning is a one-step reaction,
while respiration is a series
of reactions.
29
22.1 Basic concepts of respiration
2b Differences between burning
and respiration:
ii Burning takes place anywhere
while respiration takes place
only inside cells .
30
22.1 Basic concepts of respiration
2b Differences between burning
and respiration:
iii Burning involves no enzymes
while respiration is controlled
by many enzymes.
31
22.1 Basic concepts of respiration
2b Differences between burning
and respiration:
iv Burning is a fast and violent
reaction while respiration is a
slow and gradual reaction.
32
22.1 Basic concepts of respiration
2b Differences between burning
and respiration:
v In burning, stored energy is
released at once while in
respiration, stored energy is
released gradually .
33
22.1 Basic concepts of respiration
2b Differences between burning
and respiration:
vi In burning, energy is released
in the forms of heat and light
while in respiration, energy
released is used to form ATP
while some is lost as heat .
34
22.1 Basic concepts of respiration
3
ATP acts as an energy carrier .
When it breaks down into ADP
and a phosphate group, energy is
released and is readily usable by
cells for metabolic activities .
35
22.1 Basic concepts of respiration
4a Aerobic respiration requires
oxygen . Glucose is completely
broken down into carbon dioxide
and water . A large amount of
energy is released.
36
22.1 Basic concepts of respiration
4b
Anaerobic respiration does not
require oxygen. Glucose is partly
broken down. Much less energy
is released and different products
are formed.
37
22.2 Site of respiration
• some reactions occur in the cytoplasm,
some in the mitochondria
38
22.2 Sites of respiration
Adaptive features of
a mitochondrion
3D model
• bound by a double membrane
• outer membrane controls the movement
of substances
outer membrane
39
22.2 Sites of respiration
Adaptive features of
a mitochondrion
• inner membrane is highly folded
 provides a large surface area to pack
more enzymes
inner membrane
40
22.2 Sites of respiration
Adaptive features of
a mitochondrion
• mitochondrial matrix (基質) provides
a fluid medium for reactions to take place
• it also contains enzymes
mitochondrial matrix
41
22.2 Sites of respiration
Adaptive features of
a mitochondrion
• most energy in food is released inside
mitochondria
 active cells
contain many
mitochondria
muscle cells
42
22.2 Sites of respiration
22.1
Examination of the structure of
mitochondria
1 Examine the photomicrograph or live cell
image of a mitochondrion.
43
22.2 Sites of respiration
22.1
Examination of the structure of
mitochondria
2 Identify various structures of the
mitochondrion and draw a high
power diagram.
44
22.2 Sites of respiration
1 Some reactions of respiration
occur in the cytoplasm and some
in the mitochondria .
45
22.2 Sites of respiration
2 Structure of a mitochondrion
adapted to respiration:
a The inner membrane is
highly folded
 provides a large surface area
to pack more enzymes that
catalyse the reactions of
respiration
46
22.2 Sites of respiration
2 Structure of a mitochondrion
adapted to respiration:
b There is mitochondrial matrix
 contains enzymes for
respiration
47
22.2 Sites of respiration
2 Structure of a mitochondrion
adapted to respiration:
b There is mitochondrial matrix
 provides a fluid medium
for reactions to take place
48
22.3 Aerobic respiration
• takes place in the presence of oxygen
• three stages:
glycolysis (糖酵解)
Krebs cycle (克雷伯氏循環)
oxidative phosphorylation (氧化磷酸化)
49
22.3 Aerobic respiration
Glycolysis
• occurs in the cytoplasm
• does not require oxygen
• two main steps:
1 Breakdown of glucose to
triose phosphate
2 Oxidation of triose phosphate
to pyruvate (丙酮酸鹽)
50
22.3 Aerobic respiration
Glycolysis
1 Breakdown of glucose to
triose phosphate
glucose (6-C)
2 ATP
2 ADP + P
2 triose phosphate (3-C)
51
22.3 Aerobic respiration
Glycolysis
2 Oxidation of triose phosphate
to pyruvate
2 triose phosphate (3-C)
2 NAD
4 ADP + 4 P
2 NADH
4 ATP
2 pyruvate (3-C)
52
22.3 Aerobic respiration
Glycolysis
2 Oxidation of triose phosphate
to pyruvate
2 triose phosphate (3-C)
2 NAD
4 ADP + 4 P
2 NADH as hydrogen
4 ATP
donor
2 pyruvate (3-C)
53
22.3 Aerobic respiration
Glycolysis
• overall equation:
2 NAD
glucose
(6-C)
2 ADP + 2 P
2 NADH
2 pyruvate
(3-C)
2 ATP
transported to
mitochondrion
54
22.3 Aerobic respiration
• before entering the Krebs cycle:
2 NAD
pyruvate
(3-C)
2 NADH
acetyl-CoA
(2-C)
CO2 coenzyme A
(CoA)
55
22.3 Aerobic respiration
Kerbs cycle
• occurs in the mitochondrial matrix
• two main steps:
1 Combination of acetyl-CoA
with 4-C compound
2 Regeneration of 4-C compound
56
22.3 Aerobic respiration
Kerbs cycle
1 Combination of acetyl-CoA with
4-C compound
acetyl-CoA (2-C)
4-C
compound
CoA
6-C compound
57
22.3 Aerobic respiration
Kerbs cycle
2 Regeneration of 4-C compound
4-C
compound
6-C
compound
ATP
ADP + P
FADH
FAD
2 CO2
3 NAD
3 NADH
58
22.3 Aerobic respiration
Kerbs cycle
• each glucose molecule generates two
pyruvate molecules
 a total of six NADH, two FADH and
two ATP are formed
59
22.3 Aerobic respiration
Oxidative phosphorylation
• occurs on the inner membrane of the
mitochondrion
• two main steps:
1 Regeneration of NAD and FAD
2 Formation of ATP
60
22.3 Aerobic respiration
Oxidative phosphorylation
1 Regeneration of NAD and FAD
intermembrane space
inner
membrane
mitochondrial
matrix
61
22.3 Aerobic respiration
Oxidative phosphorylation
1 Regeneration of NAD and FAD
H
hydrogen
carrier
NADH NAD
62
22.3 Aerobic respiration
Oxidative phosphorylation
1 Regeneration of NAD and FAD
H
H
NADH NAD
FADH FAD
H2O
H
+
O
63
22.3 Aerobic respiration
Oxidative phosphorylation
2 Formation of ATP
H
H
NADH NAD
ADP+P ATP
H
FADH FAD
+
O
H2O
64
22.3 Aerobic respiration
Oxidative phosphorylation
2 Formation of ATP
• one NADH can generate three ATP
• one FAD can generate two ATP
65
22.3 Aerobic respiration
Oxidative phosphorylation
2 Formation of ATP
Glycolysis:
2 NADH
Pyruvate to
acetyl-CoA:
2 NADH
Krebs cycle:
6 NADH
2 FADH
= 6 ATP
= 6 ATP
= 22 ATP
Total: 34 ATP
66
22.3 Aerobic respiration
Let’s summarize the
overall process of
aerobic respiration.
67
22.3 Aerobic respiration
68
22.3 Aerobic respiration
Overall equation:
C6H12O6
enzymes
6 O2
6 CO2
6 H2O
38 ATP
69
22.3 Aerobic respiration
22.2
Video
Investigation of carbon dioxide
production in a living mouse
Carbon dioxide turns lime water
milky. The air breathed out by a
mouse is passed through lime water
to see whether the mouse has
produced carbon dioxide or not.
70
22.3 Aerobic respiration
22.2
Investigation of carbon dioxide
production in a living mouse
1 Place a mouse on a glass plate and cover it
with a bell jar. Smear the edge of the bell jar
with vaseline to make the bell jar airtight.
2 Set up the apparatus as shown. Note the
colours of the solutions in flasks A, B and C.
71
22.3 Aerobic respiration
22.2
Investigation of carbon dioxide
production in a living mouse
air in
bell jar
KOH lime water
A
B
to suction
pump
lime water
C
72
22.3 Aerobic respiration
22.2
Investigation of carbon dioxide
production in a living mouse
3 Turn on the suction pump to draw a stream
of air through the apparatus for 30 minutes.
Record any colour changes in the flasks.
73
22.3 Aerobic respiration
22.2
Results and discussion
The potassium hydroxide solution in flask A
does not change its colour. It absorbs carbon
dioxide in the air. This prevents carbon dioxide
from entering the bell jar.
The lime water in flask B remains clear. This
shows that the air entering the bell jar contains
no carbon dioxide.
74
22.3 Aerobic respiration
22.2
Results and discussion
The lime water in flask C turns milky after
some time. This shows that carbon dioxide is
present in the air leaving the bell jar, which
must have been given out by the living mouse.
75
22.3 Aerobic respiration
22.3
Video
Investigation of carbon dioxide
production in germinating seeds
Seeds germinate when conditions are
favourable. During germination, their
respiration greatly speeds up to release more
energy to support growth.
76
22.3 Aerobic respiration
22.3
Investigation of carbon dioxide
production in germinating seeds
Hydrogencarbonate indicator can be
used to detect any carbon dioxide
produced by germinating seeds.
Its colour changes with the
concentration of carbon dioxide.
77
22.3 Aerobic respiration
22.3
Investigation of carbon dioxide
production in germinating seeds
Concentration
Colour of
of CO2
hydrogencarbonate indicator
> 0.03%
Yellow
~ 0.03%
Red/orange
< 0.03%
Purple
78
22.3 Aerobic respiration
22.3
Investigation of carbon dioxide
production in germinating seeds
1 Set up the apparatus as shown. Leave the
tubes for a few hours.
A
soaked
germinating
seeds
moist cotton wool
wire gauze
hydrogencarbonate
79
indicator
22.3 Aerobic respiration
22.3
Investigation of carbon dioxide
production in germinating seeds
1 Set up the apparatus as shown. Leave the
tubes for a few hours.
B
boiled
seeds
moist cotton wool
wire gauze
hydrogencarbonate
80
indicator
22.3 Aerobic respiration
22.3
Investigation of carbon dioxide
production in germinating seeds
2 Record any colour changes in the
hydrogencarbonate indicator of tubes
A and B.
81
22.3 Aerobic respiration
22.3
Results and discussion
The hydrogencarbonate indicator in tube B
remains red while that in tube A turns yellow
after a few hours. These results show that
germinating seeds give out carbon dioxide.
82
22.3 Aerobic respiration
22.4
Video
Investigation of heat production in
a living mouse
1 Set up the differential air thermometer
as shown.
83
22.3 Aerobic respiration
22.4
Investigation of heat production in
a living mouse
graph paper
clip
arm A
arm B
test
tube
coloured liquid
in U-shaped
capillary tube
cotton
wool
84
22.3 Aerobic respiration
22.4
Investigation of heat production in
a living mouse
2 Open the clips on both sides of the
thermometer. Wait until the coloured liquid
levels in arms A and B become the same.
3 Close the clips. Record any changes in the
liquid levels after 10 minutes.
85
22.3 Aerobic respiration
22.4
Results and discussion
At the end of the experiment, the liquid level in
arm A rises and the liquid level in arm B falls.
This is because the mouse releases heat which
warms up the air in the test tube on the side
where it is. The expansion of air inside the tube
increases the pressure. This causes the liquid
level in arm B to fall. The results therefore
86
show that a living mouse releases heat.
22.3 Aerobic respiration
22.4
Results and discussion
The clips are opened before the experiment
starts to equalize the pressure on both sides of
the U-shaped capillary tube. The cotton wool is
used as an insulator to prevent heat loss so that
the result is more easily observed.
87
22.3 Aerobic respiration
22.5
Video
Design an investigation of heat
production in germinating seeds
From Practical 22.4, we know that a
living mouse produces heat when it carries
out respiration. Do germinating seeds
produce heat during respiration as well?
Try to design and perform an investigation
to find out the answer.
88
22.3 Aerobic respiration
Different stages of aerobic
respiration:
1 Glycolysis occurs in cytoplasm .
• Glucose is split into two
molecules of triose phosphate
using energy from ATP
89
22.3 Aerobic respiration
Different stages of aerobic
respiration:
1 Glycolysis occurs in cytoplasm .
• Triose phosphate is oxidized to
pyruvate ; NADH and ATP
are formed
90
22.3 Aerobic respiration
Different stages of aerobic
respiration:
1 Glycolysis occurs in cytoplasm .
• Net amount of ATP formed: 2
91
22.3 Aerobic respiration
Different stages of aerobic
respiration:
2 Conversion of pyruvate to
acetyl-CoA occurs in
mitochondrial matrix .
• Pyruvate is converted to
acetyl-CoA; carbon dioxide and
NADH are formed
92
22.3 Aerobic respiration
Different stages of aerobic
respiration:
2 Conversion of pyruvate to
acetyl-CoA occurs in
mitochondrial matrix .
• Net amount of ATP formed: 0
93
22.3 Aerobic respiration
Different stages of aerobic
respiration:
3 Krebs cycle occurs in mitochondrial
matrix.
• Acetyl-CoA combines with a 4-C
compound to form a 6-C
compound
94
22.3 Aerobic respiration
Different stages of aerobic
respiration:
3 Krebs cycle occurs in mitochondrial
matrix.
• The 6-C compound is oxidized
step by step to regenerate 4-C
compound; carbon dioxide, NADH,
FADH and ATP are formed
95
22.3 Aerobic respiration
Different stages of aerobic
respiration:
3 Krebs cycle occurs in mitochondrial
matrix.
• Net amount of ATP formed: 2
96
22.3 Aerobic respiration
Different stages of aerobic
respiration:
4 Oxidative phosphorylation occurs in
inner membrane of mitochondrion.
• NADH and FADH lose hydrogen .
They are oxidized to regenerate
NAD and FAD
97
22.3 Aerobic respiration
Different stages of aerobic
respiration:
4 Oxidative phosphorylation occurs in
inner membrane of mitochondrion.
• The oxidation of NADH and FADH
releases energy to form ATP by
phosphorylation
98
22.3 Aerobic respiration
Different stages of aerobic
respiration:
4 Oxidative phosphorylation occurs in
inner membrane of mitochondrion.
• Hydrogen is finally accepted by
oxygen to form water
99
22.3 Aerobic respiration
Different stages of aerobic
respiration:
4 Oxidative phosphorylation occurs in
inner membrane of mitochondrion.
• Net amount of ATP formed: 36
100
22.4 Anaerobic respiration
• does not require oxygen
• all reactions occur in the cytoplasm only
• starts with glycolysis but will not
proceed to the Kerbs cycle and
oxidative phosphorylation
101
22.4 Anaerobic respiration
How does anaerobic
respiration occur?
102
22.4 Anaerobic respiration
1 Formation of lactic acid (乳酸)
in muscles
glucose (6-C)
2 ADP + 2 P
2 NAD
2 ATP
2 NADH
2 pyruvate (3-C)
glycolysis
103
22.4 Anaerobic respiration
1 Formation of lactic acid (乳酸)
in muscles
2 pyruvate (3-C)
2 NADH
2 NAD
2 lactic acid (3-C)
104
22.4 Anaerobic respiration
1 Formation of lactic acid (乳酸)
in muscles
• produces only two ATP through
glycolysis
• simple and can supply energy quickly
105
22.4 Anaerobic respiration
1 Formation of lactic acid (乳酸)
in muscles
• the formation of lactic acid by anaerobic
respiration is called lactic acid
fermentation (乳酸發酵)
• overall equation:
glucose
energy (2 ATP)
2 lactic acid
106
22.4 Anaerobic respiration
1 Formation of lactic acid (乳酸)
in muscles
• anaerobic respiration provides
additional energy in a very short time
 allows muscles to
contract more powerfully
and at a higher rate
107
22.4 Anaerobic respiration
1 Formation of lactic acid (乳酸)
in muscles
• lactic acid formed builds up in muscles
and causes pain
 muscle fatigue (肌肉疲勞)
108
22.4 Anaerobic respiration
amount of O2
breathed in
1 Formation of lactic acid (乳酸)
in muscles
rest exercise recovery
rest
time
• after doing strenuous exercise, our
breathing remains deep for some time
109
22.4 Anaerobic respiration
amount of O2
breathed in
1 Formation of lactic acid (乳酸)
in muscles
oxygen debt (氧債)
rest exercise recovery
rest
time
• extra oxygen is used to break down
lactic acid
110
22.4 Anaerobic respiration
amount of O2
breathed in
1 Formation of lactic acid (乳酸)
in muscles
oxygen debt (氧債)
rest exercise recovery
rest
time
• lactic acid is broken down to CO2 and
water or converted to glycogen
111
22.4 Anaerobic respiration
2 Formation of ethanol and
carbon dioxide in yeast
glucose (6-C)
2 ADP + 2 P
2 NAD
2 ATP
2 NADH
2 pyruvate (3-C)
glycolysis
112
22.4 Anaerobic respiration
2 Formation of ethanol and
carbon dioxide in yeast
2 pyruvate (3-C)
2 NADH
2 CO2
2 NAD
2 ethanol (2-C)
113
22.4 Anaerobic respiration
2 Formation of ethanol and
carbon dioxide in yeast
• the formation of ethanol by anaerobic
respiration is called alcoholic
fermentation (酒精發酵)
• overall equation:
glucose
energy
(2 ATP)
2 ethanol
2 CO2
114
22.4 Anaerobic respiration
22.6
Video
Demonstration of anaerobic respiration
in germinating seeds
Germinating seeds can carry out
anaerobic respiration when there is
no oxygen. It is shown by removing
oxygen from the set-up.
The gas released is tested with
hydrogencarbonate indicator.
115
22.4 Anaerobic respiration
22.6
Demonstration of anaerobic respiration
in germinating seeds
The production of carbon dioxide in the
absence of oxygen indicates the occurrence
of anaerobic respiration.
116
22.4 Anaerobic respiration
22.6
Demonstration of anaerobic respiration
in germinating seeds
1 Put the seeds into a boiling tube and then
place a piece of wire gauze. Fill the tube
with paraffin oil.
boiling tube
wire gauze
soaked germinating
117
seeds
22.4 Anaerobic respiration
22.6
Demonstration of anaerobic respiration
in germinating seeds
2 Invert the tube and insert it into a container
of paraffin oil. Do not trap any air between
the seeds and the oil.
paraffin oil
118
22.4 Anaerobic respiration
22.6
Demonstration of anaerobic respiration
in germinating seeds
3 Leave the tube for a few hours and record
the change in oil level. Collect the gas as
pull the plunger to
shown.
collect the gas
syringe
gas
collected
rubber
119
tubing
22.4 Anaerobic respiration
22.6
Demonstration of anaerobic respiration
in germinating seeds
4 Bubble the gas through hydrogencarbonate
indicator as shown.
push the plunger to
gas
force
out
the
gas
collected
hydrogencarbonate
indicator
120
22.4 Anaerobic respiration
22.6
Results and discussion
The colour of the indicator changes from
red/orange to yellow. This shows that the gas
produced is carbon dioxide. The germinating
seeds can respire anaerobically when oxygen
is absent.
121
22.4 Anaerobic respiration
Applications of anaerobic
respiration
• the brewing of beer makes
use of the alcohol formed
when yeast ferments the
sugar in barley (大麥)
122
22.4 Anaerobic respiration
Applications of anaerobic
respiration
• the brewing of wine
makes use of the
alcohol formed when
yeast ferments the
sugar in grape juice
123
22.4 Anaerobic respiration
Applications of anaerobic
respiration
• CO2 formed by
alcoholic fermentation
in yeast helps raise
dough in bread-making
124
22.4 Anaerobic respiration
Applications of anaerobic
respiration
• yoghurt contains lactic
acid formed by anaerobic
respiration in bacteria
125
22.4 Anaerobic respiration
Applications of anaerobic
respiration
• lactic acid formed by
anaerobic respiration
in bacteria helps
coagulate milk to
form cheese
126
22.4 Anaerobic respiration
Applications of anaerobic
respiration
• ethanol formed by the
fermentation of sugar
in crops can be used
as a fuel to power
vehicles
127
22.4 Anaerobic respiration
1 Anaerobic respiration in
skeletal muscles:
Glucose undergoes glycolysis
and is oxidized to pyruvate . NADH
and ATP are formed in the process.
Pyruvate is reduced to lactic acid
by NADH .
128
22.4 Anaerobic respiration
2 Anaerobic respiration in
muscles
provides additional energy in a very
short time for muscle contraction .
129
22.4 Anaerobic respiration
3 During strenuous exercise, the
lactic acid formed by anaerobic
respiration accumulates in muscles
and causes muscle fatigue .
130
22.4 Anaerobic respiration
3 We keep breathing deeply after
exercise to take in extra oxygen .
It is used to remove all lactic acid by
breaking it down to carbon dioxide
and water or converting it to
glycogen .
131
22.4 Anaerobic respiration
4 Anaerobic respiration in yeast:
Glucose undergoes glycolysis and
is oxidized to pyruvate. NADH and
ATP are formed in the process.
Pyruvate is reduced to ethanol
by NADH. Carbon dioxide is
released in the process.
132
22.4 Anaerobic respiration
5a
Similarities of aerobic and
anaerobic respiration:
Both release energy from the
oxidative breakdown of organic
substances .
133
22.4 Anaerobic respiration
5a
Similarities of aerobic and
anaerobic respiration:
Both transfer energy to the energy
carrier ATP , and some energy is
lost as heat .
134
22.4 Anaerobic respiration
5a
Similarities of aerobic and
anaerobic respiration:
Both consist of a number of
reactions controlled by enzymes .
135
22.4 Anaerobic respiration
5b Differences between aerobic
and anaerobic respiration:
Aerobic respiration occurs in
cytoplasm and mitochondria
while anaerobic respiration occurs
only in cytoplasm .
136
22.4 Anaerobic respiration
5b Differences between aerobic
and anaerobic respiration:
Aerobic respiration requires
oxygen but anaerobic
respiration does not.
137
22.4 Anaerobic respiration
5b Differences between aerobic
and anaerobic respiration:
In aerobic respiration, organic
substances are completely broken
down into carbon dioxide and
water .
138
22.4 Anaerobic respiration
5b Differences between aerobic
and anaerobic respiration:
But in anaerobic respiration,
organic substances are partly
broken down to form lactic acid
or ethanol and carbon dioxide.
139
22.4 Anaerobic respiration
5b Differences between aerobic
and anaerobic respiration:
In aerobic respiration, 38 ATP per
glucose molecule is formed (a
larger amount of energy is
released).
140
22.4 Anaerobic respiration
5b Differences between aerobic
and anaerobic respiration:
In anaerobic respiration, 2 ATP
per glucose molecule is formed
(a much smaller amount of energy
is released).
141
22.4 Anaerobic respiration
6
Alcoholic fermentation in yeast is
used in brewing beer and wine ,
raising dough in bread-making and
producing ethanol as a biofuel.
142
22.4 Anaerobic respiration
6 Lactic acid fermentation
in
bacteria is used in making yoghurt
and cheese.
143
22.5 Relationship between
respiration and photosynthesis
• exchange of molecules between
respiration and photosynthesis
 bridges the flow of energy from the
environment to organisms
144
22.5 Relationship between respiration and photosynthesis
Exchange of molecules
light
H2O
H2O
photochemical
reactions
oxidative
phosphorylation
chloroplast mitochondrion
O2
O2
145
22.5 Relationship between respiration and photosynthesis
Exchange of molecules
CO2
CO2
Calvin
cycle
Krebs
cycle
glycolysis
glucose
pyruvate
146
22.5 Relationship between respiration and photosynthesis
Flow of energy
oxygen
glucose
photosynthesis
CO2
water
respiration
147
22.5 Relationship between respiration and photosynthesis
In energy transformation
• ATP acts as the energy carrier
energy
stored in
organic
compounds
ATP
light
energy
energy for
cellular
metabolism
ADP
+P
ADP
+P
ATP
148
22.5 Relationship between respiration and photosynthesis
In energy transformation
• ATP acts as the energy carrier
energy
stored in
photosynthesis organic
ADP
compounds
+P
ATP
light
energy
energy for
cellular
metabolism
ADP
+P
respiration
ATP
149
22.5 Relationship between respiration and photosynthesis
Differences between respiration
and photosynthesis:
1 Site of occurrence:
Respiration occurs in all living
cells while photosynthesis occurs in
chloroplast-containing cells
150
22.5 Relationship between respiration and photosynthesis
Differences between respiration
and photosynthesis:
2 Type of metabolism:
In respiration, catabolism occurs.
Organic food is broken down by
oxidation to release energy
151
22.5 Relationship between respiration and photosynthesis
Differences between respiration
and photosynthesis:
2 Type of metabolism:
In photosynthesis, anabolism
occurs. Organic food is built up by
reduction to store energy
152
22.5 Relationship between respiration and photosynthesis
Differences between respiration
and photosynthesis:
3 Energy change:
In respiration, chemical energy in
food is converted to ATP and heat
153
22.5 Relationship between respiration and photosynthesis
Differences between respiration
and photosynthesis:
3 Energy change:
In photosynthesis, light energy from
the sun is converted to chemical
energy in food
154
22.5 Relationship between respiration and photosynthesis
Differences between respiration
and photosynthesis:
4 Cyclic reactions:
In Krebs cycle of respiration,
carbon dioxide is removed from
the substrate and ATP , NADH
and FADH are formed
155
22.5 Relationship between respiration and photosynthesis
Differences between respiration
and photosynthesis:
4 Cyclic reactions:
In Calvin cycle of photosynthesis,
carbon dioxide is fixed into the cycle
by a 5-C compound and NADPH
and ATP are used
156
22.5 Relationship between respiration and photosynthesis
Differences between respiration
and photosynthesis:
5 Formation of ATP:
In respiration, ATP is formed in
glycolysis, Krebs cycle and
oxidative phosphorylation
157
22.5 Relationship between respiration and photosynthesis
Differences between respiration
and photosynthesis:
5 Formation of ATP:
In photosynthesis, ATP is formed in
photophosphorylation
158
22.5 Relationship between respiration and photosynthesis
Differences between respiration
and photosynthesis:
6 Hydrogen donor:
In respiration, NADH and FADH
are the hydrogen donors while in
photosynthesis, water is the
hydrogen donor
159
22.5 Relationship between respiration and photosynthesis
Differences between respiration
and photosynthesis:
7 Final hydrogen acceptor:
In respiration, oxygen is the final
hydrogen acceptor while in
photosynthesis, a 3-C compound
in Calvin cycle is the final hydrogen
acceptor
160
1
How does our body obtain energy
from the food we eat?
Our body releases energy stored in food
by respiration. The energy is used to
form ATP which drives all cellular
activities.
161
2
How is alcohol produced from corn
by fermentation?
Sugar in corn is converted to ethanol by
alcoholic fermentation in yeast.
162
3
The sugar in corn is made by
photosynthesis. What is the relationship
between respiration and photosynthesis?
Respiration and photosynthesis together
allow the flow of energy in the ecosystem.
163
Respiration
is
requires
oxygen
does not
require
oxygen
anaerobic
aerobic
respiration respiration
oxidative
breakdown of food
164
oxidative
breakdown of food
releases
chemical energy
mostly as
heat
some
stored in
ATP
165
aerobic
respiration
anaerobic
respiration
both involve
glycolysis
occurs in
cytoplasm
166
glycolysis
if aerobic, then
followed by
Kerbs
cycle
occur in
oxidative
phosphorylation
mitochondria
167
glycolysis
if anaerobic,
then followed by
formation of
lactic acid
occur in
formation of ethanol
and carbon dioxide
cytoplasm
168