Unit 8 Flashcards
(196 cards)
1
Q
Where is energy stored?
A
ATP
2
Q
What does ATP do?
A
Provide energy for cellular activities
3
Q
Cellular Respiration
A
reactions that break down organic monomers to release energy for ATP production
4
Q
How is ATP (adenosine triphosphate) made?
A
by adding a phosphate group to ADP (adenosine diphosphate)
5
Q
What does the formation of ATP from ADP require?
A
energy from food/glucose
6
Q
What is ATP hydrolyzed into? (2)
A
- phosphate group
- ADP
7
Q
What does the break down of ATP into ADP release?
A
Energy that can be used for cellular work
8
Q
phosphorylate
A
add a phosphate group to a molecue
9
Q
What happens when a molecule gains a phosphate group? (2)
A
- becomes unstable
- becomes highly reactive
10
Q
What do cells use ATP for? (5)
A
- skeletal muscle
- cardiac muscle
- liver
- extraocular
- retinal
11
Q
What are the reactants for the cellular respiration equation? (2)
A
- oxygen
- glucose
12
Q
What are the products for the cellular respiration equation? (3)
A
- carbon dioxide
- water
- ATP
13
Q
How are breathing and cellular respiration related? (2)
A
- breathing bring O2 into the body and distributes it to cells via blood
- O2 is used in mitochondria to make ATP and breathing disposes of the CO2 waste product
14
Q
When are electrons moved?
A
when extracting energy
15
Q
When are electrons gained?
A
when receiving energy
16
Q
oxidation (2)
A
- loss of electrons
- loss of energy
17
Q
reduction (2)
A
- addition of electrons
- addition of energy
18
Q
What happens when glucose is oxidized? (2)
A
- loses high energy electrons/H atoms
- catabolic/glucose is broken down to release energy
19
Q
What happens when O2 is reduced? (2)
A
- gains low energy electrons/H atoms
- oxygen accepts H to make water
20
Q
What do high energy electron do on their way to oxygen?
A
donate some of their energy to generate ATP
21
Q
Describe cell respiration in terms of metabolism. (2)
A
- It is a series of enzyme catalyzed reactions.
- It is catabolic.
22
Q
Describe the conversion of ADP into ATP. (3)
A
- When a phosphate group is added, adenosine diphosphate becomes adenosine triphosphate.
- Adding a phosphate group is called phosphorylation.
- ATP production requires energy from food.
23
Q
List three cellular processes that use ATP as a source of energy. (3)
A
- Muscular contractions
- Protein synthesis
- Active transport
24
Q
What types of respiration can ATP be made by? (2)
A
- aerobic
- anaerobic
25
Aerobic (3)
- uses oxygen
- yields more ATP than anaerobic respiration
- four stages of reaction are used to extract energy from food to make ATP
26
Anaerobic (3)
- doesn't use oxygen
- yields far less ATP than aerobic respiration
- only one reaction stage is completed
27
What is the aerobic respiration overall reaction?
carbohydrate + oxygen ---> carbon dioxide + water + energy (38 ATPs)
28
What are the stages of aerobic respiration? (4)
1) glycolysis
2) link reaction
3) Kreb's Cycle
4) Electron Transport Chain & Chemiosmosis
29
What do stages 1-3 aerobic respiration do? (2)
- 4 ATP
- lots of energized electrons
30
What does stage 4 of aerobic respiration do?
use energized electrons to make 34 ATP
31
Glycolysis
the splitting of sugar
32
Where does glycolysis occur?
cytoplasm
33
Electron carriers (NADH)
carry energy held by energized electrons to the electron transport chain to make ATP
34
What does glycolysis not require?
oxygen
35
What are key points about glycolysis? (3)
- first occurred before the atmosphere had oxygen
- uses enzymes to catalyze reactions
- produces ATP by substrate-level phosphorylation
36
State the mechanism by which glycolysis produces ATP. (1)
Substrate-level phosphorylation
37
Outline the process of glycolysis. (6)
1) Glycolysis occurs in the cytoplasm.
2) Starting off with glucose, that glucose is phosphorylated to become hexose bisphosphate which requires 2 ATPs.
3) Another phosphate is added to the triose phosphate to become triose biphosphate which is then oxidized causing it to lose energy/H+
4) In turn, NAD+ is reduced to NADH and 4 ADPs are reduced to 4 ATPs
5) The rest of what is left from the triose phosphates is two pyruvate molecules
6) Overall, there is a net gain of 2 ATPs.
38
After glycolysis is that enough?
No, there is energy left in the pyruvate
39
What happens after glycolysis?
If oxygen is available, pyruvate will enter the mitochondria where it will be further oxidized.
40
What happens in cellular respiration is oxygen is present?
reactions move to the mitochondria
41
matrix
contains enzymes and solutes for link reaction and Kreb's Cycle
42
Inner mitochondrial membrane
site for electron transport chain and oxidative phosphorylation
43
Cristae (2)
- folded inner mitochondrial membrane
- meant to maximize surface area for reactions
44
Small inter-membrane space
more efficient generation of H+ concentration gradient
45
Outline the structure of a mitochondrion. (6)
- It is circular
- It has a smooth outer membrane
- Within the inner membrane is the matrix - Matrix is the inner compartment within the inner membrane
- There are ribosomes and circular DNA in the matrix
- The intermembrane space is between the outer and inner membranes.
46
70S Ribosomes
protein production
47
What is the step after glycolysis?
link reaction
48
What does the link reaction do?
modify pyruvate so it can enter the next stage (Kreb's cycle)
49
What are the components of pyruvate?
carbons
50
Explain the link reaction. (6)
- The link reaction can also be known as the oxidative decarboxylation of pyruvates.
- When a pyruvate enters the link reaction, which occurs when oxygen is present, it attaches to coenzyme A.
- In the process, it is oxidized and decarboxylated.
- Where a carboxyl group, CO2 is lost, which becomes a waste product of the link reaction.
- It also loses electrons/ H atoms/ energy via oxidation which goes to NAD+ which is reduced to NADH.
- The result from this reaction after happening 2 times is 2 NADH and 2 Acetyl CoA, which was left of the pyruvate after the CO2 was lost. These things go onto the next stage, the Krebs cycle.
51
decarboxylation
removal of carboxyl group and releasing it as CO2
52
Where does the link reaction occur?
matrix of the mitochondria
53
What is another name for the link reaction?
oxidative decarboxylation
54
What is oxidative decarboxylated in the link reaction?
pyruvate
55
How is pyruvate oxidative decarboxylated? (2)
decarboxylated - because CO2 is lost
oxidized - because it loses H atoms/e-/energy
56
What is the waste from the link reaction?
2CO2
57
What is the net yield from the link reaction? (2)
- 2 acetyl CoA per glucose molecule (because there are two pyruvates to go through the link reaction)
- 2NADH/2H+
58
What is stage 3 of cellular respiration?
the Krebs Cycle
59
When does the Kreb's Cycle occur?
when oxygen is present
60
Where does acetyl CoA come from?
the link reaction
61
What is acetyl CoA used for in the Krebs Cycle?
to make citric acid
62
What happens to citric acid in the Krebs Cycle? (2)
- it is broken down in the Krebs cycle to release energy
- energy is transferred to electron carriers and used to make ATP directly
63
Where does the Krebs Cycle occur?
the matrix
64
What are the steps of the Krebs Cycle? (8)
- acetyl CoA brings its carbons to oxaloacetate
- citric acid is formed
- the coenzyme goes back to the link reaction
- citric acid goes through oxidative decarboxylation
- citric acid is oxidized
- NAD+ is reduced to NADH H+
- CO2 is waste product using oxygen
- 5 carbon is result
- 5 carbon goes through oxidative decarboxylation (same result as citric acid)
- 4 carbon goes goes through oxidative decarboxylation
- ADP --> ATP through substrate level phosphorylation
- FAD reduced to FADH2
- NAD+ reduced to NADH H+
- returns back to oxaloacetate
65
How many carbons does acetyl CoA have?
2
66
How many carbons does oxaloacetate have?
4
67
How many carbons does citric acid have?
6
68
What does the Kreb's cycle produce for 1 glucose? (3)
- 2 ATP
- 6 NADH, 2 FADH2 (electron carriers)
- 4 CO2
69
What does substrate-level phosphorylation do in the Kreb's Cycle?
produce ATP
70
Indicate two places where decarboxylation occurs. (1)
Going from citric acid to C5 and going from C5 to oxalacetate
71
What does oxidative decarboxylation make in the Kreb's cycle? (3)
make:
- NADH
- FADH2
- CO2
72
Which releases more energy to the cell? Glycolysis or Krebs cycle?
Krebs cycle
73
Why does the Krebs cycle produce more energy? (2)
- it produces a lot of NADH and FADH2
- most of the energy from glucose is still in electrons at the end of the Kreb's cycle
74
Where do electron carriers take electrons?
the ETC
75
electron transport chain
removes energized electrons from carriers and uses energy to build a concentration gradient
76
chemiosmosis
uses concentration gradient to make ATP
77
What does ETC + chemiosmosis equal?
oxidative phosphorylation
78
oxidative phosphorylation
using energy from oxidation of electron carriers to make ATP
79
What brings high energy electrons to the ETC? (2)
- NADH
- FADH2
80
What is the location of the ETC in eukaryotic and prokaryotic cells? (2)
eukaryotic cells: mitochondria
prokaryotic cells: plasma membrane
81
Explain how chemical energy for use in the cell is generated by electron transport and chemiosmosis. (8)
- The chemical energy needed can be obtained through the oxidation of NADH and FADH2.
- When these are oxidized, they donate energy to the ETC.
- The ETC is a series of protein proton pumps that pump H atoms from the matrix into the intermembrane space.
- The electrons release energy as they flow along the chain from carrier to carrier.
- The ETC uses the energy from the high energy electrons to pump the H atoms.
- When the atoms run out of energy, they are accepted by oxygen which is the terminal electron acceptor.
- ATP synthase enzymes are located in the inner mitochondrial membrane.
- The energy is released as protons pass down their gradient through ATP synthase enzymes. ATP synthase converts ADP to ATP.
82
What is the terminal electron acceptor?
oxygen
83
What does oxygen accept low energy electrons and protons for?
to form water
84
How many ATP are produced from oxidative phosphorylation?
34
85
What are the 34 ATP made from?
electron carriers from:
-glycolysis
- link reaction
- Krebs cycle
86
Which and how many electron carriers does glycolysis contribute?
2 NADH
87
What electron carrier does link reaction contribute?
2 NADH
88
What electron carriers does Krebs cycle? (2)
- 6 NADH
- 2 FADH2
89
How many ATP is made from 1 glucose?
38
90
Where to the 38 ATPs come from?
- 2 ATP from glycolysis
- 2 ATP from Krebs cycle
- 34 ATP from ETC & chemiosmosis
91
mitochondrion (2)
- produces energy for the cell
- many in active cells
92
anaerobic respiration
occurs when oxygen is absent
93
How much ATP is produced from anaerobic respiration?
2 ATP per glucose
94
How many stages of anaerobic respiration are there?
2
95
What are the stages of anerobic respiration? (2)
1) glycolysis (2 ATP)
2) fermentation (0 ATP)
96
fermentation
converts sugar to acids, gasses and/or alcohol
97
What does anaerobic respiration in animals release?
lactic acid fermentation
98
When does lactic acid fermentation happen in animals?
when cells don't have much oxygen during bursts of high intensity exercise
99
What is the pathway for fermentation in animals?
1 glucose --> 2 pyruvates -->lactate
100
When does lactic acid fermentation happen in yeast, bacteria, and plants?
when cells lack oxygen
101
What is the pathway for fermentation in yeast, bacteria, and plants?
1 glucose --> 2 pyruvates --> ethanol & CO2
102
Describe the relationship between photosynthesis and cellular respiration. (2)
- The products of cellular respiration (CO2 and water) are the reactants of photosynthesis
- The anabolic pathways of photosynthesis build glucose and the catabolic pathways cell
103
What is the lactic acid fermentation formula?
pyruvate + NADH --> lactate + NAD+
104
What is the alcoholic fermentation formula?
pyruvate + NADH --> ethanol + CO2 + NAD+
105
How are anerobic and aerobic respiration applied to exercise in humans? (3)
- first few minutes of high intensity exercise is anaerobic, because of a lag in oxygen uptake
- after sometime of doing the exercise the oxygen intake increases rapidly and eventually becomes steady
- ATP can be produced through aerobic respiration
106
Within different activities, what differs concerning aerobic and anaerobic respiration?
The proportion of aerobic to anaerobic respiration
107
autotrophs (2)
- make their own energy
- convert energy from the sun or from inorganic compounds into organic compounds rich in energy
108
heterotrophs (2)
- get energy from others
- consume energy-rich organic compounds from other organisms
109
What is the energetic relationship between autotrophs and heterotrophs?
all living things rely on autotrophs to use light energy to make carbohydrates
110
Explain the movement of electrons in the general equation for photosynthesis. (2)
- Water is oxidized (loses electrons/hydrogen/energy)
- Carbon dioxide is reduced (gains electrons/hydrogen/energy)
111
Photosynthesis (2)
- anabolic pathways
- photosynthesis build glucose using light energy
112
Cellular respiration (2)
- catabolic pathways
- respiration break down glucose to extract energy
113
What is CO2 in terms of the photosynthesis equation?
a simple, low energy molecule
114
What is light in terms of the photosynthesis equation?
an energizer of electrons
115
What is glucose in terms of the photosynthesis equation?
high energy glucose is made when energized electrons are transferred to carbon dioxide
116
Why is energy needed for photosynthesis?
to build glucose from carbon dioxide
117
What happens when water is oxidized?
electrons/H atoms are removed and energized leaving O2 gas
118
What happens when carbon dioxide is reduced?
energized electrons/H atoms are transferred to CO2, making sugar
119
Where does photosynthesis occur?
chloroplast
120
What is the location of chloroplasts?
concentrated in cells of the mesophyll
121
Mesophyll
green tissue in interior leaf
122
stomata
tiny pores in a leaf through which carbon dioxide enters and oxygen exits
123
Stroma
has appropriate enzymes and a suitable pH for the Calvin cycle
124
Double Membrane
Evidence for endosymbiosis
125
Thylakoid
has ETC and ATP synthase for photophosphorylation
126
Granum
flat membrane stacks increase SA:Vol ratio and small internal volumes quickly accumulation ions
127
Lamella
connects and separates thylakoid stacks (grana)
128
How many stages does photosynthesis take place in?
2
129
Outline the structure of a chloroplast as seen with an electron microscope. (4)
An inner and outer membrane - shown as two concentric continuous lines close together
Grana - shown as a stack of several disc-shaped subunits
Thylakoids - one of the flattened sacs
Lamella - shown continuous with thylakoid membrane
130
What are the stages of photosynthesis (2)
- light-dependent reactions
- light independent reaction
131
Where does the light dependent reaction occur?
thylakoid membrane
132
Explain how light energy is converted into chemical energy in the light-dependent reactions. (10)
- Starting with photoactivation, light shines on the pigment in photosystem II
- the electrons to become excited and pass it on to chlorophyll.
- The excited electrons move on to the ETC where a gradient is being formed in the process as H atoms are being pumped into the thylakoid space using energy from the energized electrons.
- Then ATP is formed via chemiosmosis using ATP synthase.
- Photophosphorylation is also used, which is the use of light energy to energize electrons whose energy will be used to form a concentration gradient that will be used to phosphorylate ATP.
- Eventually, electrons in the ETC run out of energy
- go to photosystem I where they are reenergized through photoactivation.
- NADP+ is reduced to NADPH using electrons from photosystem I.
- The H atoms that are needed for the cycle to continue are replenished through photolysis
- water is broken down causing the loss of energy/H atoms/ electrons that are used for photosystem II.
133
Photoactivation (3)
- light is absorbed by pigment molecules in photosystem II
- this causes electron to be excited (higher energy level)
- energy is passed to chlorophyll
134
How is NADPH helpful to the light-dependent reaction?
it helps maintain the H+ concentration gradient because it binds excess H+
135
photophosphorylation
using light energy to make ATP in the light dependent reactions
136
What happens in photophosphorylation? (8)
- photosystem II absorbs light
- photoactivation produces an excited electron
- H+ is pumped across thylakoid membrane
- The absorption of light in photosystem I gives an electron to a carrier (NADP+ becomes NADPH)
- Protons pass through ATP synthase
- ATP is produced by chemiosmosis
- Photolysis occurs
- Photolysis of water produces H+/O2/e-
137
What is the biproduct of electrons being replaced through the photolysis of water?
oxygen
138
What is the result of the light dependent reaction? (2)
- ATP
- NADPH
139
Where do ATP and NADPH go after the light dependent reaction?
the light independent reactions in the stroma to make glucose
140
Outline what molecules are oxidized and reduced in the Krebs cycle and how energy is transferred by these processes. (3)
- When molecules are oxidized they lose energy
- Citric Acid, a 6 carbon molecule, and a 4 carbon molecule are oxidized and decarboxylated causing for a loss of energy/electrons/H atoms
- The lost energy/electrons/H atoms go to FAD2 and NAD+ which are reduced to FADH2 and NADH which are electron carriers.
141
Give one example of oxidative decarboxylation in the Krebs cycle. (4)
- Enzymes in the matrix remove one carbon dioxide and H/energy/electrons from citric acid.
- Oxidative decarboxylation is when a molecule is oxidized causing it to lose electrons/energy/hydrogen atoms, but it also loses a carboxyl group coming as the form of CO2.
- With citric acid, it is oxidized and loses its electrons/energy/hydrogen atoms (oxidation)
- which goes to an electron carrier (NADH), but it also loses CO2 causing it to become a 5 carbon molecule (decarboxylation).
142
Describe how the link reaction and the Krebs cycle are related. (3)
- The link reaction brings the Acetyl CoA
- used in the Krebs cycle to join with a 4 carbon compound
- Both of these processes occur in the matrix of the mitochondria
143
Outline the molecules oxidized and reduced in the ETC and how energy is transferred by these processes. (3)
- NADH and FADH2 are oxidized meaning they lose energy/electrons/H atoms
- Proton pumps are reduced in ETC meaning they gain energy/electrons/H atoms
144
Explain how the structure of a mitochondrion is adapted for its function. (3)
- The large inner surface area of the cristae is to hold more electron transport chains and make more ATP by chemiosmosis.
- The matrix contains DNA and ribosomes for protein (enzyme) synthesis and Krebs cycle enzymes.
- The double membrane isolates metabolic processes/chemical reactions from the rest of the cytoplasm. The small intermembrane space between the inner and outer membranes allows for the rapid accumulation of protons/hydrogen ions.
145
Outline the process of aerobic respiration. (6)
- The first step is glycolysis which takes place in the cytoplasm.
- Glucose is split and oxidized leaving two pyruvates
- a net gain of 2 ATP.
- Next, the pyruvates move to the matrix of the mitochondria if oxygen is present.
- CO2 is produced.
- 38 ATPs are produced per glucose molecule.
146
Distinguish between anaerobic and aerobic cell respiration in eukaryotes. (4)
- Anaerobic respiration does not require oxygen, but aerobic does
- Anaerobic happens in the cytoplasm, while aerobic happens in the mitochondria.
- Anaerobic respiration yields 2 ATP, aerobic yields 38 ATP
- Anaerobic has a product of acids, gasses, or alcohol, aerobic has a product of CO2 or water.
147
Outline anaerobic cell respiration in plant cells. (2)
- Anaerobic respiration in a plant still results in 2 pyruvates from glycolysis.
- The result is the production of CO2 or ethanol from fermentation.
148
Explain the movement of electrons in the general equation for photosynthesis. (2)
- Water is oxidized (loses electrons/hydrogen/energy)
- Carbon dioxide is reduced (gains electrons/hydrogen/energy)
149
Photosystems
groups of photopigments (including chlorophyll) in the thylakoid membrane
150
What happens when a photosystem absorbs light energy? (2)
- When a photosystem absorbs light energy, electrons within the pigments become energized
- Excited electrons are transferred to carrier molecules
151
What kind of light can photopigment electrons absorb?
certain wavelengths of visible light.
152
What light on the visible light spectrum has the shortest wavelength?
violet light
153
What light on the visible light spectrum has the longest wavelength?
red light
154
What are the primary pigments of photosynthesis? (2)
- Chlorophyll a
- Chlorophyll b
155
Chlorophyll (2)
- Absorbs blue-violet and red light, reflects green light
- Transfers excited electrons to electron carriers (NADP+)
156
Chlorophyll b (2)
- Absorbs blue and
orange light, reflects
yellow-green
- Gives excited electrons
to chlorophyll a
157
Absorption spectrum
shows wavelengths of light absorbed by a single photosynthetic pigment
158
What do chlorophyll a and b mainly absorb?
blue-violet and red-orange wavelengths
159
action spectrum
show the wavelengths of light over which photosynthesis is most active
160
Where does the light-independent reaction occur?
stroma
161
light independent reactions (3)
- use CO2, ATP, and NADPH to make a sugar called triose phosphate
- ATP and NADPH from light dependent reactions
- triose phosphate used to make glucose/other carbs.
162
What are the phases of the Calvin cycle? (3)
- carbon fixation
- reduction
- regeneration
163
Carbon fixation (3)
- taking carbon from the atmosphere and changing it into organic sugar
- 3 CO2 + 3 RuBP = 6 glycerate 3-phosphate
- reaction is catalyzed by rubisco
164
Rubisco (carboxylase)
- enzyme that catalyzes the carboxylation of ribulose bisphosphate
165
Reduction (Calvin Cycle) (4)
- glycerate 3-phosphate is reduced to triose phosphate using NADPH and ATP
- 6 glycerate 3-phosphates → 6 triose phosphates
- 6 ATP and 6 NADPH are oxidized
- The energy from ATP and NADPH causes glycerate 3-phosphate molecules to react/rearrange
166
Regeneration (3)
- some triose phosphate & ATP is used to regenerate ribulose biphosphate (RuBP)
- some triose phosphate also exits the cycle
- 3 ATP are oxidized
167
How much does the Calvin cycle use to make a triose phosphate? (3)
- 3 CO2
- 9 ATP
- 6 NADPH
168
How much does the Calvin cycle use to make a glucose? (3)
- 6 CO2
- 18 ATP
- 12 NADPH
169
Outline the relationship between a photopigment and a photosystem. (2)
- Photopigments are molecules that trap light energy.
- A photosystem is composed of a cluster of photopigments and an electron acceptor.
170
Describe the absorption spectrum for chlorophyll a. (4)
- Wavelength or color of light is plotted on the x-axis.
- Absorbance of light is plotted on the y-axis.
- On an absorption spectrum, there would be a curve over the blue-violet light and a curve over the red light.
- There would not be a curve over the green light because it is not absorbed.
171
Explain the relationship between the absorption spectrum for chlorophyll and action spectrum of photosynthesis for green plants. (3)
- An absorption spectrum depicts the wavelengths of light that chlorophyll will absorb while an action spectrum depicts the wavelengths of light at which photosynthesis is most active.
- Photosynthesis is most active when light is being absorbed because it excites the electrons in the photopigments, so the points where the chlorophyll absorbs light will be where the absorption spectrum peaks.
- The difference in the absorption spectrum of chlorophyll and the action spectrum for photosynthesis is due to the absorption by pigments other than chlorophyll such as carotene.
172
Define carboxylation, reduction, and carbon fixation. (3)
- Carboxylation - when a carboxyl group from the atmosphere is added to another molecule
- Reduction - When an electron/hydrogen atom/energy is gained as a result of another molecule being oxidized. In the light dependent reaction, 6 ATP and 6 NADPH donate their electrons/energy/hydrogen atoms to the 6 glycerate 3-phosphate turning it into a triose phosphate.
- Carbon fixation - taking carbon from the atmosphere and making it an organic sugar
173
Explain the relationship between the structure and function for the thylakoid membranes and stacks (grana) (3)
- large surface area for light absorption and reactions
- membrane-bound ATP Synthase and photosystems
- High density of chlorophyll for light absorption
174
Explain the relationship between the structure and function for the low volute thylakoid spaces
rapid generation of H+ gradient for chemiosmosis
175
Explain the relationship between the structure and function for the enzyme rich stroma (2)
- contains rubisco for carboxylation of RuBP
- fluid easy for diffusion
176
What is the chloroplast's equivalent to the outer mitochondrial membrane?
chloroplast envelope
177
What is this chloroplast's equivalent to the thylakoid membrane?
inner mitochondrial membrane
178
What is this chloroplast's equivalent to the matrix?
the stroma
179
What are direct ways photosynthesis can be measured? (2)
- rate of oxygen production
- rate of carbon dioxide uptake
180
What are indirect ways photosynthesis can be measured?
tracking changes in plant biomass/ mass of organically bound carbon
181
What is the formula for measuring the rate of oxygen produced?
oxygen produced
time
182
How is the rate of gas produced measured and what are some methods? (4)
- Oxygen gas production is measured over a period of time
- counting oxygen bubbles
- collecting oxygen gas in a syringe - using oxygen sensors
183
What is the formula for measuring the rate of carbon dioxide produced?
carbon dioxide used
time
184
How is the rate of CO2 used measured and what are some methods? (3)
- CO2 usage or increases in pH are measured over time
- pH of water surrounding a plant using pH meter or pH paper
- Decreases in CO2 are measured by using a CO2 sensor
185
What is the formula for measuring the rate in change in biomass?
change in biomass
time
186
How is the rate of change in body mass measured and what are some methods? (2)
- Biomass increase can be used as an indirect measure of the production of glucose
- Biomass can be measured by drying a plant to remove water and then finding its mass.
187
What is a limiting factor?
factor is closes to its minimum
188
Are limiting factors of photosynthesis?
- light intensity
- carbon dioxide concentration
- temperature
189
When is light intensity limiting?
at night
190
What is the result of low light intensity?
- affects light-dependent stage
- creates insufficient ATP and NADPH production
- stops the Calvin cycle from operating at maximum rate
191
Why does a graph expressing light intensity plateau?
at high light intensity, further increase has no effect on rate of reaction, as all chloroplasts are working at full efficiency
192
When is CO2 concentration limiting? (2)
- in bright light
- in warm temperatures
193
How is low CO2 concentration limiting? (2)
- it limits carbon fixation
- results in low glucose production
194
Why does the graph expressing CO2 concentration plateau?
at high concentration, further increase has no effect on rate of reaction, as CO2 is being fixed at the maximum rate of efficiency
195
When is temperature limiting?
in colder climates
196
What is the result of low temperatures?
- affect light-independent stage
- affect enzyme activity (less active at low temps)
