5A Photosynthesis and Respiration Flashcards
1
Q
Why do plants need energy?
A
- Photosynthesis
- Active transport
- DNA replication
- Cell division
- Protein synthesis
2
Q
Why do animals need energy?
A
- Muscle contraction
- Maintaining body temp
- Active transport
- DNA replication
- Cell division
- Protein synthesis
3
Q
What does photosynthesis do?
A
It is the process where energy from light is used to make glucose from water and carbon dioxide
4
Q
What is the overall equation for photosynthesis?
A
6CO2 + 6H2O + Energy –> C6H12O6 + 6O2
5
Q
How is the energy that is produced from photosynthesis stored?
A
It is stored in the glucose that is made until the plant releases it by respiration
6
Q
How do animals obtain glucose?
A
By eating plants (or other animals)
They then respire the glucose to release energy
7
Q
How do cells release the energy from glucose?
A
By respiration
8
Q
What is the energy from glucose used for in cells?
A
It is used to power all the biological processes in a cell
9
Q
What are the two types of respiration?
A
Aerobic - respiration using oxygen
Anaerobic - respiration without oxygen
10
Q
What is the equation for aerobic respiration?
A
C6H12O6 + 6O2 –> 6CO2 +6H2O + Energy
11
Q
What is C6H12O6?
A
Glucose
12
Q
What does anaerobic respiration in plants and yeast produce?
A
Ethanol, CO2 and releases energy
13
Q
What does anaerobic respiration produce in animals?
A
Lactate and energy
14
Q
What is ATP used for in a cell?
A
It is the immediate source of energy
15
Q
Why do cells use ATP for energy?
A
As a cell can’t get its energy directly from glucose
So energy released from glucose is used to make ATP
ATP carries energy around the cell where it’s needed
16
Q
How is ATP made?
A
It is synthesised via a condensation reaction between ADP and an inorganic phosphate, using energy from an energy releasing-reaction
17
Q
Which enzyme catalyses the formation of ATP?
A
ATP synthase
18
Q
Where is ATP hydrolysed?
A
In the part of the cell that needs energy
19
Q
What happens when ATP is hydrolysed (broken down)?
A
It is hydrolysed into ADP and inorganic phosphate
Chemical energy is released from the phosphate bond and is used by the cell
20
Q
Which enzyme catalyses the breakdown of ATP?
A
ATP hydrolase
21
Q
Where is the energy stored in ATP?
A
In the phosphate bend, it is released when this bond is broken
22
Q
Once ATP has been broken down, what happens the the ADP and the inorganic phosphate?
A
They’re recycled and the process starts again
23
Q
What are 6 useful properties of ATP?
A
- Small manageable amount of energy released at a time
- Small and soluble molecule
- Easily broken down
- Can be quickly re-meade
- Can make other molecules more reactive
- Can’t pass out of the cell
24
Q
Why is it useful that ATP only releases small, manageable amounts of energy at a time?
A
So no energy is wasted as heat
25
Why is it useful that ATP is a small soluble molecule?
So it can be easily transported around the cell
26
Why is it useful that ATP is easily broken down?
So energy can be released instantaneously
27
How can ATP make other molecules more reactive?
By transferring one of its phosphate groups to them (phosphorylation)
28
Why is it useful that ATP can't pass out of the cell?
So the cell always has an immediate supply of energy
29
What is a metabolic pathway?
A series of small reactions controlled by enzymes
e.g. respiration or photosynthesis
30
What is phosphorylation?
Adding phosphate to a molecule
e.g. ADP is phosphorylated to ATP
31
What is photophosphorylation?
Adding phosphate to a molecule using light
32
What is photolysis?
The splitting (lysis) of a molecule using light (photo) energy
33
What is photionisation?
When light energy 'excites' electrons in an atom/molecule, giving them more energy & causing them to be released
The release of electrons causes the atom or molecule to become a positively-charged ion
34
What is hydrolysis?
The splitting (lysis) of a molecule using water (hydro)
35
What is decarboxylation?
The removal of CO2 from a molecule
36
What is dehydrogenation?
The removal of hydrogen from a molecule
37
What is a redox reaction?
Reactions that involve oxidation and reduction
38
What happens when something is reduced?
It has gained electrons
May have gained hydrogen or lost oxygen
39
What happens when something is oxidised?
It has lost electrons
May have lost hydrogen or gained oxygen
40
Give 2 example of where coenzymes are used
- Photosynthesis
| - Respiration
41
What is a coenzyme?
A molecule that aids the function of an enzyme
42
How do coenzymes work?
By transferring a chemical group from one molecule to another
43
What is the coenzyme used in photosynthesis called?
NADP
44
What does NADP do?
NADP transfers hydrogen from one molecule to another
This means it can REDUCE (give hydrogen to) or OXIDISE (take hydrogen from) a molecule
45
What are the coenzymes used in respiration?
- NAD
- Coenzyme A
- FAD
46
What do NAD and FAD do in respiration?
They transfer hydrogen from one molecule to another
This means they can REDUCE (give hydrogen to) or OXIDISE (take hydrogen from) a molecule
47
What does coenzyme A do in respiration?
It transfers acetate between molecules
48
Where does photosynthesis take place in the cell?
In the chloroplasts
They are flattened organelles , surrounded by a double membrane
49
What are thylakoids?
Fluid-filled sacs found in the chloroplasts
50
What are grana?
Stacks of thylakoids
51
How are grana linked?
By bits of thylakoid membrane called lamellae
52
Where are the photosynthetic pigments found?
In the thylakoid membranes in chloroplasts
They are attached to proteins
53
Give 3 examples of photosynthetic pigments
- Chlorophyll A
- Chlorophyll B
- Carotene
54
What are photosynthetic pigments?
They are coloured substances that absorb the light energy needed for photosynthesis
55
What is the protein and photosynthetic pigment called when they're together?
A photosystem
56
How many photosystems are used by plants to capture light energy?
2
57
What are the names of the photosystems used by plants?
- Photosystem 1 (or PSI)
| - Photosystem 2 (or PSII)
58
What wavelength of light does PSI absorb best?
700 nm
59
What wavelength of light does PSII absorb best?
680 nm
60
What is the stroma?
It is a gel-like substance contained within the inner membrane of the chloroplast and it surround the thylakoids
61
What does the stroma contain?
- Enzymes
- Sugars
- Organic acids
62
What happens to carbohydrates produced by photosynthesis?
They are not used up straight away, they are stored as starch grains in the stroma
63
What are the 2 stages that photosynthesis can be split into?
- The light dependent reaction reaction
| - The light independent reaction
64
What does the light dependant reaction in photosynthesis need?
Light energy, as suggested by the name
65
Where does light dependant photosynthesis take place?
In the thylakoid membranes of the chloroplasts
66
What happens to H2O in the light dependent reactions?
it is oxidised into O2
67
Where is light absorbed in the light dependant photosynthesis reaction?
By the chlorophyll (and other photosynthetic pigments) in the photosystems
68
How does chlorophyll become photoionised?
Light energy (absorbed by the chlorophyll) excites the electrons in the chlorophyll
This leads to their eventual release from the molecule - the chlorophyll has been photoionised
69
What is the energy produced from the light dependant photosynthesis reaction used for?
- Some is used to add a phosphate group to ADP to make it ATP
- Some is used to reduce NADP to form reduced NADP
70
What is the role of the ATP and NADP produced by the light dependent photosynthesis reaction?
ATP --> transfers energy
NADP --> transfers hydrogen to the light-independent reaction
71
What is another name for the light independent reaction?
The Calvin cycle
72
Does the calvin cycle use light energy?
It doesn't use light energy directly
But it does rely on the products of the light dependent reaction
73
Where does the light independent reaction take place?
In the stroma of the chloroplast
74
How is ATP and reduced NADP used in the light independent reaction?
They supply the energy & hydrogen to make simple sugars from CO2
75
In the light dependent reaction how is ATP made?
By photophosphorylation
76
In the light dependent reaction, what is the energy from the photoionisation of chlorophyll used for?
- Making ATP from ADP and inorganic phosphate
- Making reduced NADP from NADP
- Splitting water into protons (H+ ions), electrons and oxygen
77
What is the process of splitting water into protons (H+ ions), electrons and oxygen called?
Photolysis
78
What is the process of making ATP from ADP and inorganic phosphate called?
Photophosphorylation
79
What are the two type of photophosphorylation in the light independent reaction called?
- Non-cyclic
| - Cyclic
80
What does non-cyclic photophosphorylation produce?
ATP, reduced NADP and O2
81
What are the photosystems in the thylakoid membranes linked by?
Electron carriers
82
What are electron carriers?
Proteins that transfer electrons
83
What is an electron transport chain?
A chain of proteins through which excited electrons flow
formed by the photosystems and electron carriers
84
What are the main stages of light dependent photosynthesis?
1) Light energy excites electrons in chlorophyll
2) Photolysis of water produces protons (H+ ions), electrons and O2
3) Energy from the excited electrons makes ATP...
4) ...and generates reduced NADP
85
What happens to excite the electrons in chlorophyll in photosynthesis?
(stage 1 of light dependent photosynthesis)
- Light energy absorbed by PSII
- Light energy excites electrons in chlorophyll
- Electrons move to a higher energy level (have more energy)
- The high-energy electrons are released from the chlorophyll & moved down the electron transport chain to PSI
86
What happens for the photolysis of water in photosynthesis?
| stage 2 of light dependent photosynthesis
- As excited electrons from chlorophyll leave PSII, they must be replaced
- Light energy splits water into protons (H+ ions), electrons & oxygen - photolysis
87
What is the equation for the photolysis of water in the chlorophyll?
H2O --> 2H+ + 1/2O2
88
How does the energy from excited electrons make ATP in photosynthesis?
(stage 3 of light dependent photosynthesis)
- Excited electrons lose energy as they move down the electron transport chain
- Lost energy is used to transport protons into the thylakoid so the thylakoid has a higher conc. of protons than the stroma
- This forms a protein gradient across the thylakoid membrane
- Protons move down their conc. gradient, into the stroma, via the enzyme ATP synthase, which is embedded in the thylakoid membrane
- The energy from this moment combines ADP & inorganic phosphate to form ATP
89
How is reduced NADP produced from ATP in photosynthesis?
| stage 4 of light dependent photosynthesis
- Light energy is absorbed which excites the electrons again to an even higher energy level
- Finally, the electrons are transferred to NADP, along with a proton (H+ ions) from the stroma - to form reduced NADP
90
What is chemiosmosis?
The process of electrons flowing down the electron transport chain and creating a proton gradient across the membrane to drive ATP synthesis
It's described by the chemiosmotic theory
91
What is the light-independent reaction (photosynthesis) also called?
The Calvin Cycle
92
Where does the Calvin Cycle (light-independent reaction) take place?
The stroma on the chloroplast
93
What does the Calvin Cycle make and what from?
A molecule called triose phosphate
| From CO2 and ribulose bisphosphate
94
What is ribulose bisphosphate?
A 5-carbon compound
95
What can ribulose bisphosphate be used for?
To make glucose and other useful organic substances
96
What does the Calvin Cycle need to keep it going?
It needs ATP and H+ ions
97
What is the Calvin Cycle like?
There are a few steps in the cycle and the reactions are in a linked cycle which means the starting compound, ribulose bisphosphate, is regenerated
98
What are the 3 main stages in the Calvin Cycle?
1 - CO2 is combined with the ribulose bisphosphate to form two molecules of glycerate 3-phosphate
2 - ATP and reduced NADP are required for the reduction of GP to triose phosphate
3 - Ribulose bisphosphate is regenerated
99
What happens in the first stage of the Calvin Cycle (where CO2 is added)?
- CO2 enters leaf through stomata & diffuses into the stroma of the chloroplast
- CO2 is combined with ribulose bisphosphate (RuBP), a 5 carbon compound
- Unstable 6 carbon molecule is made, it quickly breaks down two molecules of a 3-carbon compound called glycerate 3-phosphate (GP)
100
What happens in the second stage of the Calvin Cycle (ATP and reduced NADP used)?
- Hydrolysis of ATP (from light-dependent reaction) provides energy to turn 3-carbon compound (GP), into a different 3-carbon compound, triose phosphate (TP)
- This reaction needs H+ ions which come from reduced NADP (from L-D reaction), reduced NADP is recycled to NADP
- Some triose phosphate is converted to useful organic compounds (e.g. glucose) & some continues in Calvin Cycle to regenerate RuBP
101
What happens in the third stage of the Calvin Cycle (Ribulose bisphosphate is regenerated)?
- 5/6 molecules of TP produced aren't used to make hexose sugars, but to regenerate RuBP
- Regenerating RuBP uses the rest of the ATP produced by the L-D reaction
102
What are TP and GP converted to after the Calvin Cycle?
They are converted into useful organic substances like glucose
103
What is the Calvin Cycle the starting point for?
It is the starting point for making all the organic substances plants need
104
What are triose phosphate and glycerate 3-phosphate (from the Calvin Cycle) used for?
To make carbohydrates, lipids and amino acids
105
What are the general optimum conditions for photosynthesis?
- High light intensity of a certain wavelength
- Temperature around 25 degrees
- Carbon dioxide at 0.4%
106
Why is light important for photosynthesis?
Light is needed to provide the energy for the light-dependent reaction
The higher the intensity of the light, the more energy it provides
107
What are the 3 photosynthetic pigments?
- Chlorophyll a
- Chlorophyll b
- carotene
108
What types of light can the photosynthetic pigments absorb?
They can only absorb the red and blue light in sunlight
109
Why is green light not absorbed and used for photosynthesis?
Green light is reflected as the chlorophyll is green, which is why the plant appears green
110
What are the enzymes involved in photosynthesis?
ATP synthase and rubisco
111
Why does the temperature for photosynthesis have to be 25 degrees?
The enzymes involved cannot function below 10 degrees and will denature above 45 degrees
112
What happens to the stomata when the temperature is too high?
High temperatures cause the stomata to close to avoid losing too much water
This caused photosynthesis to slow down because less CO2 enters the leaf when stomata are closed
113
What % of the atmosphere is CO2
0.04%
114
Why is the optimum amount of CO2 0.4% and not 0.04%?
Increasing it to 0.4% gives a higher rate of photosynthesis but any higher than this the stomata will close
115
How are carbohydrates made during the Calvin Cycle?
Also known as hexose sugars
Are made by joining two triose phosphate molecules
Larger carbohydrates are made by joining hexose sugars together in different ways
116
How are lipids made during the calvin cycle?
They are made using glycerol - which is synthesised from triose phosphate & fatty acids
these are synthesised from glycersate 3-phosphate
117
How are amino acids made during the calvin cycle?
Some amino acids are made from glycerate 3-phosphate
118
How many times does the calvin cycle need to turn to make one hexose sugar?
Six times
119
Why does the calvin cycle have to turn 6 times to make one hexose sugar?
1) 3 turns produce 6 molecules of triose phosphate (TP) - two molecules of TP are produced for every one CO2 molecule used
2) 5/6 TP molecules used to regenerate ribulose bisphosphate (RuBP)
3) This means for 3 turns 1 TP is produced that's used to make hexose sugar
4) Hexose sugar has 6 carbons, so 2 TP needed to form one hexose sugar
5) Means the cycles must turn 6 times to produce 2 molecules of TP that can be used to make 1 hexose sugar
6) 6 turns of the cycle need 18 ATP & 12 reduced NADP from the light-dependent reaction
120
How much ATP and reduced NADP is needed for 6 turns of the Calvin Cycle?
- 18 ATP
| - 12 reduced NADP
121
What are the ideal conditions for photosynthesis?
- High light intensity of a certain wavelength
- Temp around 25 degrees
- CO2 at 0.4%
122
Why is light important for photosynthesis?
Light is needed to provide the energy for the light-dependent reaction
The higher the intensity of the light, the more energy it provides
123
What are the 3 photosynthetic pigments?
- Chlorophyll a
- Chlorophyll b
- Carotene
124
What are the light wavelengths that photosynthetic pigments can absorb?
Red and blue light in sunlight
125
Why can’t plants absorb green light?
It is reflected, as the chlorophyll is green so it cannot be absorbed
This is why plants look green
126
Give two example of enzymes used in photosynthesis
ATP synthase and rubisco
127
Why must the temperature be around 25 degrees for photosynthesis?
Photosynthesis involves enzymes
If the temp falls below 10 degrees the enzymes become inactive
If the temp is more than 45 degrees the enzymes with start to denature
Also affects stomata
128
What happens to stomata on plants if the temperature becomes too high
High temps cause stomata to close to avoid losing too much water
Causes photosynthesis to slow down as less CO2 enters the leaf when the stomata are closed
129
How much CO2 is in the atmosphere?
It makes up 0.04% of gases in the atmosphere
130
Why is the optimum CO2 levels 0.4% and not 0.04%?
Increasing the levels to 0.4% gives a higher rate of photosynthesis
But any higher and the stomata would close
131
Why is water key to photosynthesis?
Plants need a constant supply of water
- Too little and photosynthesis would stop
- Too much and the soil becomes waterlogged
132
Why is it bad for the plant if there is too much water?
The soil becomes waterlogged
It reduces the uptake of minerals ie magnesium which is needed to make chlorophyll a
133
What are the limiting factors of photosynthesis?
Light, temperature and CO2
134
What happens if one of the limiting factors of photosynthesis is too high or low?
It will limit photosynthesis (slow it down)
Even if the other two factors are at the perfect level it won't make any difference due to the one at the wrong level
135
On a warm sunny day what would be the limiting factor for photosynthesis?
CO2
136
At night what is the limitng factor for photosynthesis?
The light intensity
137
What is the saturation point in photosynthesis?
Where a factor is no longer limiting the reaction - something else has to become the limiting factor
138
What do growers use info about limiting factors for?
To increase plant growth
139
How do farmers/growers control CO2 conc. ina greenhouse?
CO2 is added to the air
e.g. by burning a small amount of propane in a CO2 generator
140
How do farmers/growers control light intensity in a greenhouse?
Light can get through the greenhouse glass
| Lamps provide light at night time
141
How do farmers/growers control temperature in a greenhouse?
Glasshouses trap heat energy from sunlight which warms the air
Heaters & cooling systems can also be used to keep a constant optimum temp & air circulation systems make sure the temp is even throughout glasshouse
142
What are the two types of respiration?
- Aerobic
| - Anaerobic
143
Do both areobic & anaerobic respiration both produce ATP?
They both do - but anaerobic produces less
144
What do both aerobic and anaerobic start with?
They both start with glycolysis but the stages can differ
145
What does glycolysis make?
It makes pyruvate from glucose
146
What does glycolysis involve?
It involves splitting one molecule of glucose (with 6 carbons) into two smaller molecules of pyruvate (3C)
147
Where does glycolysis happen?
The process happens in the cytoplasm of cells
148
Is glycolysis anaerobic or aerobic?
It is an anaerobic process
It is the first stage of both aeorobic & anaerobic respiration and doesnt need oxygen
149
What are the two stages in glycolysis?
- Phosphorylation
| - Oxidation
150
What happens in phosphorylation (first stage of glycolysis)?
1 - Glucose is phosphorylated using a phosphate from a molecule of ATP. This creates 1 molecule of glucose phosphate and 1 molucule of ADP
2 - ATP is then used to add another phosphate, forming hexose bisphosphate
3 - Hexose bisphosphate is then split into 2 molecules of triose phosphate
151
What happens in oxidation (second stage of glycolysis)?
1 - Triose phospahte is oxidised (loses hydrogen), forming 2 molecules of pyruvate
2 - NAD collects the hydrogen ions, forming 2 reduced NAD
3 - 4 ATP are produced, but 2 were used up in stage 1, so there's a net gain of 2 ATP
152
What is the overall reaction for glycolysis?
ATP is used to phosphorylate glucose to triode phosphate
Then triose phosphate is oxidised, releasing ATP
Overall there’s a net gain of 2 ATP and 2 reduced NAD
153
What are the products of glycolysis?
2 reduced NAD
2 molecules of pyruvate
2 ATP
154
Where does the reduced NAD from glycolysis go to?
It goes to oxidative phosphorylation
155
Where do the two pyruvate molecules from glycolysis go?
They are actively transported into the matrix of the mitochondria for the link reaction
156
What happens in anaerobic respiration after glycolysis?
Pyruvate is converted to either ethanol or lactate depending on whether it’s an animal or a plant
157
What happens to pyruvate in anaerobic respiration in plants?
- It is reduced to ethanal first (CO2 is released)
| - Then ethanol is produced (it is reduced by reduced NAD when it turns into NAD)
158
What is anaerobic respiration in plants called?
Alcoholic fermentation
159
What is anaerobic respiration in animals called?
Lactate fermentation
160
What happens in anaerobic respiration in animals?
Pyruvate is reduced to lactic acid - it is reduced by reduced NAD being oxidised
161
What does the link reaction do?
It converts pyruvate to acetyl coenzyme A
162
Is ATP produced in the link reaction?
No it is not
163
What is the order of respiration?
1) Glycolysis
2) Link reaction
3) Krebs cycle
4) Oxidative phosphoralation
164
What are the products of the krebs cycle?
- 1 coenzyme A
- 2 oxaloacetate
- 2 CO2
- 1 ATP
- 3 reduced NAD
- 1 reduced FAD
165
What does oxidative phosphorylation produce lots of?
ATP
166
Explain the whole process of oxidative phosphorylation
1) Hydrogen atoms released from FAD & NAD and split into protons and electrons
2) Electrons move down transport chain
3) Energy from this is used to pump protons from mitochondrial matrix into intermembrane space
4) Concentration of protons is higher in intermembrane space so forms a gradient
5) Protons move down the gradient through ATP synthase (makes ATP from ADP and P)
6) At end of transport chain protons, electrons and O2 form water
167
In oxidative phosphorylation where are the hydrogen atoms (protons and electrons) released from?
Reduced NAD and FAD
168
What happens at the electric transport chain in oxidative phosphorylation?
Electrons move down transport chain losing energy at each carrier?
169
What gradient is formed in oxidative phosphorylation from protons?
Electrochemical gradient
170
How do the protons go through ATP synthase?
They diffuse
171
What is the process of ATP production driven by movement of H+ ions across a membrane called?
Chemiosmosis
172
How much ATP can be made from 1 glucose molecule?
32
173
What molecules are produced at glycolysis?
2 ATP
| 2 reduced NAD
174
What sort of reactions occur in the Krebs cycle?
A series of oxidation-reduction reactions
175
What molecules are produced at the krebs cycle?
2 ATP
6 reduced NAD
2 reduced FAD
176
What happens in the first stage of the Krebs cycle?
1 - Acetyl CoA from link reaction combines ith 4-carbon molecule (oxaloacytate) to form a 6-carbon molecule (citrate)
2 - CoA goes back to link reaction to be used again (acetyl group is used)
177
How much ATP is made for every reduced FAD?
1.5 ATP from every reduced FAD
178
Explain the process of the link reaction
1 - Pyvurvate is decarboxylated (carbon atom removed from pyruvate in the form of CO2)
2 - Pyruvate is oxidised to form acetate & NAD is reduced to form reduced NAD
3 - Acetate is combined with coenzyme A (CoA) to form acetyl coenzyme A (acetyl CoA)
4 - No ATP produces in this reaction
179
What are the products of the link reaction?
- Acetyl CoA
- CO2
- Reduced NAD
180
Which stage in respiration is oxidative phosphorylation?
The fourths stage (last stage)
181
Why does the link reaction happen twice for every glucose molecule?
Two pyruvate molecules are made for every glucose molecule that enters glycolysis
Therefore the link reactiona and the Krebs cycle happen twice for every glucose molecule
182
After the link reaction, what has been produced from one molecule of glucose (in total)?
- Two molecules of a CoA (go to Krebs cycle)
- Two CO2 molecules (released as waste products)
- Two molecules of reduced NAD (go to oxidative phosphorylation)
183
What does the Krebs cycle produce?
Reduced coenzymes and ATP
184
Where does the Krebs cycle take place?
In the matrix of the mirochondria
185
What sort of reactions occur in the Krebs cycle?
A series of oxidation-reduction reactions
186
What disease can affect ATP production?
mitochondrial disease
187
How is respiration affected by mitochondrial disease?
Affect how proteins function in the krebs cycle and oxidative phosphorylation
188
What does mitochondrial disease lead to?
- Increase in anaerobic respiration (makeup for less ATP)
- Lots of lactate produced, causes muscle fatigue and weakness
- Some lactate diffuses into blood stream, leading to high concentration of lactate in the blood
189
What other respiratory substrates can be used in aerobic respiration?
Fatty acids, lipids and amino acids
190
How many times does the Krebs cycle happen per pyruvate molecule?
Once for every pyruvate molecule
So twice for every glucose molecule
191
What happens in the first stage of the Krebs cycle?
1 - Acetyl CoA from link reaction combines ith 4-carbon molecule (oxaloacytate) to form a 6-carbon molecule (citrate)
2 - CoA goes back to link reaction to be used again (acetyl group is used)
192
Which stage in respiration is glycolysis?
The first stage
193
Which stage in respiration is the link reaction?
The second stage
194
Which stage in respiration is the Krebs cycle?
The thid stage
195
Which stage in respiration is oxidative phosphorylation?
The fourths stage (last stage)
196
What happens in the second part of the Krebs cycle?
1 - 6C cirtate molecule converted to 5C molecule (lost as CO2)
2 - Decarboxylation occurs (caused CO2 to be removed)
3 - Dehydrogenation occurs - hydrogen is removed
4 - Lost hydrogen is used to produce reduced NAD from NAD
197
What happens in the third stage (final) of the Krebs cycle?
1 - 5C molecule converted to 4C
2 - Decarboxylation & dehydrogenation occur, produces 1 molecule reduced FAD & two reduced NAD
3 - ATP produced - direct transfer of phosphate group from intermediate compund to ADP - citrate converted to oxaloacetate
198
What happens overall in the Krebs cycle?
1a - Acetyl CoA from link reaction combines ith 4-carbon molecule (oxaloacytate) to form a 6-carbon molecule (citrate)
1b - CoA goes back to link reaction to be used again (acetyl group is used)
2a - 6C cirtate molecule converted to 5C molecule (lost as CO2)
2b - Decarboxylation occurs (caused CO2 to be removed)
2c - Dehydrogenation occurs - hydrogen is removed
2d - Lost hydrogen is used to produce reduced NAD from NAD
3a - 5C molecule converted to 4C
3b - Decarboxylation & dehydrogenation pccur, produces 1 molecule reduced FAD & two reduced NAD
3c - ATP produced - direct transfer of phosphate group from intermediate compund to ADP - citrate converted to oxaloacetate
LOOK AT TEXTBOOK!!!! piss of lucy
199
What organisms are used to investigate factors affecting respiration?
yeast
200
Why are yeast used to investigated respiration?
When respire both aerobically and anaerobically CO2 is produced, this can used used to test the respiration rate
201
How do your measure CO2 production?
gas syringe
202
Explain process of temperature on aerobic respiration experiment?
1) put known volume and substrate solution in a tube, add buffer to maintain PH
2) place test tube in water bath to temperature being tested, leave for 10 mins so temperature of substrate can stabilize
3) add dried yeast and stir for 2 mins, until dissolved
4) put bung with tube attached to gas syringe in top of tube, should be at 0
5) start stop watch as soon as bung on test tube
6) at intervals record volume of CO2
7) repeat 3 times with different temperatures and one with no yeast as a control
203
Explain process of temperature on anaerobic respiration experiment?
1) put known volume and substrate solution in a tube, add buffer to maintain PH
2) place test tube in water bath to temperature being tested, leave for 10 mins so temperature of substrate can stabilize
3) add dried yeast and stir for 2 mins, until dissolved
4) trickle liquid paraffin down inside of test tube so completely covers surface, stops oxygen
5) start stop watch as soon as bung on test tube
6) at intervals record volume of CO2
7) repeat 3 times with different temperatures and one with no yeast as a control
