Respiration and Photosynthesis Flashcards
(132 cards)
1
Q
What is cellular respiration
A
Cells harvest chemical energy stored in organic molecules and use it to generate ATP
2
Q
What is the cellular respiration formula
A
organic molecules + oxygen -> water, carbon dioxide, energy
3
Q
What is the formula for catabolic breakdown of glucose
A
C6H12O6 + 6O2 -> 6CO2 +6H2O +energy
4
Q
What is oxidized in the breakdown of glucose
A
Glucose - Carbon dioxide
C6H12O6- 6CO2
5
Q
What is reduced in the breakdown of glucose
A
Oxygen -> water
6O2 -> 6H2O
6
Q
What does the oxidation of glucose do
A
It transfers e- to a lower energy state, releasing energy to be used in ATP synthesis
7
Q
During cellular respiration what is the path the electrons will follow
A
Most electrons will follow a “downhill” exergonic pathway
glucose -> NADH -> ETC -> oxygen
8
Q
What is an energy harvest
A
Glucose is broken foe in steps to harvest energy.
Electrons are taken from glucose at different steps
9
Q
What does the election travel with during energy harvest
A
Electrons travel with a proton (H+)
10
Q
How many protons and electrons does dehydrogenases take from glucose
A
2 electrons
2 protons
11
Q
What is dehydrogenase
A
an oxidizing agent for glucose
12
Q
How is NAD reduced to NAHD
A
the energy harvest transfers 2e and 1 proton to coenzyme NAD to reduce to NADH
13
Q
Where is the other proton sent during energy harvest
A
the other proton is released into surrounding solution as H+
14
Q
How are electrons (e-) transferred to the electron transport chain
A
NADH carries e- to electron transport chain
15
Q
What is the electron transport chain
A
A sequence of membrane proteins that shuttle electrons down a series of redox reactions
16
Q
What is released from the electron transport chain
A
it releases energy used to make ATP
17
Q
What does the electron transport chain transfer
A
ETC transfers e- to oxygen to make water and it releases energy
18
Q
What are the stages of cellular respiration
A
Glycolysis
Citric cycle
Oxidative phosphorlylation (ETC and chemisoisis)
19
Q
What is glycolysis
A
starting point of cellular respiration
splits glucose (6C) into 2 pyruvates (3C)
20
Q
Where does glucose occur
A
Cytosol
21
Q
what is the 1st stage of glycolysis
A
Energy investment stage: the cell uses ATP to phsophorylate compounds of glucose
22
Q
what is the 2nd stage of glycolysis
A
Energy payoff stage: energy is produced by substrate level phosphorylation
23
Q
What is the energy investment of glycolysis
A
2 ATP -> 2 ADP+P
24
Q
What is the energy payoff of glycolysis
A
4 ADP+P -> 4 ATP
25
How must citric acid cycle start
If oxygen is present, the pyruvate enters the mitochondria
26
What is pyruvate oxidized into
Acetyl CoA
27
what is Acetyl CoA
Acetyl is used to make citrate in the citric acid cycle
28
what is produced from the pyruvate oxidation
2 CO2 and 2 NADH
29
What is the citric acid cycle also known as
Krebs cycle
30
Where does the citric acid cycle take place
Mitochondrial matrix
31
What is produced from the citric acid cycle
Turns Acetyl CoA into citrate
releases CO2
ATP Synthesized
Electrons transferred to NADH and FADH2
32
What is the output from Citric acid cycle
2 ATP
6 NADH
4 CO2
2 FADH2
33
What does oxidative phosphorylation consist of:
Electron transport chain
Chemisomosis
34
Where is the electron transport chain located
The electron transport chain located in the inner membrane of the mitochondria
35
What is the electron transport chain
Collection of proteins
As electrons "fall" proteins alternate between reduced (accepts e-) and oxidized (donate e-) state
36
What is the cristae
The cristae increases the surface area for reactions to occure during ETC
37
Does the electron transport chain produce ATP
No
It helps manage the release of energy by creating several small steps for "fall" of electrons
38
What is the final electron acceptor
Oxygen
Each pairs with 2H+ and 2e- to form H2O
39
What is the major function of the ETC
ONe major functiopn is to cerate a proton (H+) gradient across the membrane
40
How does the gradient in the ETC work
As protein shuttles electrons along the ETC, they also pump H+ into the intermembrane space
It uses exergonic flow of electrons from NADH and FADH2
41
What does the gradient from the ETC power
This gradient will power chemisomosis
Uses hydrogen ions to power cellular work
42
What is ATP synthase
The enzyme that makes ATP from ADP+P
43
What energy does ATP synthase use
Uses energy from the H+ gradient across the membrane
44
Where does the H+ ions flow during chemisomisis
H+ ions flow down their gradient through ATP synthase
45
What does ATP synthase act as
Rotor
When H+ binds the rotor spins
Activates catalytic sites to turn ADP+P into ATP
46
How much ATP is made during ATP synthase
26-28 ATP per glucose
47
What was the input for oxidative phosphorylation
10 NADH and 2 FADH2
48
What was the output for oxidative phsorphorylation
26-28 ATP
49
What are two ways organisms produce ATP in the absensce of oxygen
Anaerobic respiration
Fermentation
50
What is anareobic respriration
generates ATP using an ETC in the absense
51
How does anaerobic respiration work
Takes place in prokaryotic organisms that live in environments with no oxygen
52
What is the final electron acceptor in anaerobic respiration
sulfates or nitrates
53
What is fermentation
Generates ATP without an ETC
Extension of glycolysis
54
Where does fermentation occur
Cytosol
55
What is recycled in fermentation
NAD+
56
What are two types of fermentation
Alcohol fermentation
Lactic acid fermentation
57
What is alcohol fermentation
pyruvate is converted into ethanol
58
What are some examples of alcohol fermentation
Examples: yeast and bacteria
59
What is lactic acid fermentation
2 pyruvate is reduced directly by NADH to form lactate
60
What are examples of lactic acid fermentation
Muscle cells
When muscle cells run out of oxygen, they can go through lactic acid fermentation to produce ATP
61
What is the breakdown of lactate
Muscles produce lactate, which goes into the blood and is broken down back to glucose in the liver
When lactate is in the blood, it lowers pH
If lactate builds up and is unable to be broken down ir can lead to lactic acidosis
Excessively low pH
62
What is photosynthesis
conversion of light energy to chemical energy
63
What are autotrophs
organisms that produce their own food (organic molecules) from simple substances in their surroundings
64
What are heterotrophs
organisms unable to make their own food so they live off of other organisms
65
Where did photosynthesis first evolve from
Photosynthesis first evolved from prokaryotic organisms
Prokaryotic photosynthetic pathways were the foundation of eukaryotic photosynthesis
66
What is cyanobacteria
early prokaryotes capable of photosynthesis
Oxygenated atmosphere during early earth
67
What is the primary location for photosynthesis
leaves
68
What is the chloroplast
organelle for the location of photosynthesis
69
Where is the chloroplast found
Found in the mesophyll, the cells that make up the interior tissue of the leaf
70
What is the stomata
Pores in leaves that allow CO2 in and O2 out
71
What is the chloroplast surrounded by
Double membrane
72
What re the structures of the chloroplast and define them
Stroma: aqueous
Thylakoids: form stacts known as grana
Chlorophyll: green pigment in thylakoid membranes
73
What is the formula for photosynthesis
6CO2 +6H2O + light energy --> C6H12O6 +6O2
74
What are the reactants of photosynthesis
6O2 and 12 H2O
75
What are the products of photosynthesis
C6H12O6, 6H2O, 6O2
76
What are the 2 stages of photosynthesis
Light reaction (photo) and calvin cycle (synthesis)
77
What is light
electromegnetic energy
Travels in waves
78
What is light made up of
particles of energy called protons
79
What is a wavelength
Distance from the crest of one wave to the crest of the next
80
What is the range of electrons
The entire range is known as the electromagnetic spectrum
380-750 is visible
81
What level of energy is in short wave lengths vs. long wavelengths
High energy and low energy
82
When light interacts with matter is can be....
Reflected, transmitted, absorbed
83
What is able to absorb visible light
Pigments
84
What type of color is what we are able to see
reflected
Example: leaves are green because chlorophyll absorbs violet-blue and red light, so it reflects green
85
What is chlorophyll a
Primary pigment
Involved in light reactions
Blue/Green pigment
86
What is chlorophyll b
Accessory pigment
Yellow/Green pigment
87
What are caretenoids
Broaden the spectrum of colors that drive photosynthesis
Yellow/Orange pigment
88
What is photoprotection
caretenoids absorb and dissipate excessive light energy that could damage chlorophyll or interact with oxygen
89
What is the light reactions
converts solar energy to chemical energy
90
Where does light reactions occur
Thylakoid membrane
91
What forms are the chemical energy from light reactions in
NADPH and ATP
92
Why is light important to a chlorophyll
The chlorophyll absorbs a photon of light
e- is boosted from a ground state to an excited state
e- is unstable
falls back to ground state
releases energy as heat
emits photons as fluorescent
93
What are photosystems
Reaction center and light capturing complexes
94
What is the reaction center
complex of proteins associated with the chlorophyll and a electron acceptor
95
What are light capturing complexes
pigments associated with proteins
Antenna for the reaction centers
96
What are the two photosystems found in the thylakoid membrane and define them
Photosystem 2: reaction center P680
Photosystem 1: reaction center P700
97
How is ATP generated
"Fall" of electrons from PS2-PS1 provides energy to form ATP
98
What is a form of potential energy
H+ Gradient
99
What is the input for light reaction
H2O, ADP, NADP+
100
What is the output for light reactions
O2, ATP, NADPH
101
What is role of the water being split
Provides a source of electrons and protons (H+)
Releases O2 as a by-product
102
What is the role of the light that was absorbed
Light absorbed by the chlorophyll drives the transfer of electrons and hydrogen ions from H2O to an electron acceptor called NADP+
103
What is NADP+ reduced to in light reactions
NADPH
104
How is ATP generated in light reactions
Generates ATP by phosphorylation ADP
105
What is the calvin cycle
Cyclic electron flow
106
What does the calvin cycle use
It uses ATP and NADH to reduce CO2 to sugar
107
What are the 3 phases of the calvin cycle
Carbon fixation
Reduction
Regeneration of RuBP
108
Define phase 1 of the calvin cycle: Carbon fixation
CO2 is incorporated into the calvin cycle one at a time
Each CO2 is attached to a molecule of RuBP
109
What does the RuBP form once bonded with CO2
3-phosphoglycerate
110
Define phase 2 of the calvin cycle: Reduction
Each molecule of 3-phosphoglycerate is phosphorylated by ATP (6)
It becomes 3-biphosphogycerate
111
What does 3-biphosphoglycerate
reduced G3P
6 molecules of G3P are formed but 5 are used to regenerate RuBP
112
Define the 3rd phase of the calvin cycle: Regeneration of RuBP
5 molecules of G3P are used to regenerate 3 molecules of RuBP
113
How much ATP is used during the 3rd phase of the calvin cycle
3 ATP
114
What was the input of the calvin cycle
3 CO2, 9 ATP, 6NADPH
115
What was the output of the calvin cycle
1 G3P, 9ADP, 6NADP+
116
What are the main problems with C3 plants
On very hot days, plants close their stomata to stop water loss
Causes less CO2 to be present, and more O2
RuBP binds with O2 and uses ATP
No process produces CO2, no sugar produced, bad for plant
117
What are the adaptations C3 and C4 plants developed
Plants that live in hot, dry, climates have evolved to have alternate mechanisms of carbon fixation
118
What are the special characteristics of the C4 plant
Spatial separation of steps
Stomata partially close to conserve water
Mesophyll cell fix CO2 into a 4-c molecule (releases CO2 to be used in calvin cycle)
119
What are examples of C4 plants
Maize (corn), grasses, sugarcane
120
What are the special characteristics for CAM plants
Open stomata at night and close during the day
CO2 is incorporated into organic acids and stored in vacuoles
During the day, light reactions occur and CO2 is released from the organic acids and incorporated into the calvin cycle
121
What are examples of CAM plants
Pineapples, cacti, succulents, jade
122
Why does photorespiration decrease the efficiency of photosynthesis
It reduces the amount of sugar present
123
A flask containing photosynthetic green algae and a control flask containing water with no algae are both placed under a bank of lights, which are set to cycle between 12 hours of light and 12 hours of dark. The dissolved oxygen concentrations in both flasks are monitored. Predict what the relative dissolved oxygen concentrations will be in the flask with algae compared to the control flask.
The concentration of dissolved oxygen in the flask with algae will be higher in the light, but lower in the dark.
124
Which statement most accurately describes the process of respiration
Releases CO2 and Oxygen
It occurs continuously in the cells of all organisms
and usually involves an exchange of gases
125
Where are ATP synthase complexes located in a plant cell?
thylakoid membranes and inner mitochondrial membranes
126
The NADPH required for the Calvin cycle is produced by which of the following metabolic reactions?
reactions initiated in photosystem 1
127
Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. The best way to detect the lack of photosystem II in these organisms would be
to determine if they have thylakoids in the chloroplasts.
128
Which process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent?
glycolysis
129
An inorganic molecule required by green plants for the
the
process of photosynthesis is
carbon dioxide
130
The products of aerobic respiration in green plants are ATP and
carbon dioxide and water
131
If a cell is able to synthesize 30 ATP molecules for each molecule of glucose completely oxidized to carbon dioxide and water, approximately how many ATP molecules can the cell synthesize for each molecule of pyruvate completely oxidized to carbon dioxide and water?
14
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