Exam 3 Flashcards
(161 cards)
1
Q
What is photosynthesis?
A
The process utilized by autotrophs to manufacture organic food molecules
2
Q
What is the equation for cellular respiration?
A
6CO2+6H2O+Sunlight= C6H12O6+6O2
3
Q
What is the equation for glucose?
A
C6H12O6
4
Q
What produces glucose and O2
A
Photosynthesis
5
Q
What is cellular respiration?
A
The process utilized by autotrophs and heterotrophs to harvest the chemical energy of organic food molecules
6
Q
What requires the use of glucose and O2?
A
Cellular respiration
7
Q
What is the equation for cellular respiration?
A
C6 H12 O6 + 6O2 →→→ 6CO2 + 6H2O + ATP
8
Q
What happens within an ecosystem?
A
Nutrients cycle and energy flows
9
Q
Are cellular respiration reactions exergonic or endergonic?
A
Exergonic
10
Q
What happens during redox reactions?
A
Hydrogens are transferred from glucose to oxygen
11
Q
What is oxidation?
A
The loss of electrons
12
Q
What is reduction?
A
The gain of electrons
13
Q
When glucose loses hydrogens what happens?
A
Glucose is oxidized into carbon dioxide
14
Q
When oxygen gains hydrogens what happens?
A
Oxygen is reduced into water
15
Q
Where does glycolysis occur?
A
In the cytosol of a cell
16
Q
What does glycolysis produce?
A
2 molecules of ATP, 2 NADH
17
Q
How many molecules of ATP does glycolysis require?
A
2
18
Q
What happens to G3P and NAD+ in glycolysis?
A
G3P molecules are oxidized and NAD+ is reduced into NADH
19
Q
Does glycolysis require oxygen?
A
No
20
Q
How is ATP formed during glycolysis?
A
Substrate-level phosphorylation
21
Q
Where does pyruvate oxidation occur?
A
In the matrix of of a cell’s mitochondria
22
Q
What does pyruvate oxidation produce?
A
2 molecules of ATP, 8 of NADH, 2 of FADH
23
Q
What happens to acetic acid in pyruvate oxidation?
A
It is oxidized
24
Q
What happens to NAD+ in pyruvate oxidation?
A
NAD+ is reduced to NADH
25
What does pyruvate oxidation reaction produce?
2 CO2, 2 NADH, 2 acetyl CoA
26
What does the citric cycle produce?
4 Co2, 2 ATP, 6 NADH, 2FADH
27
What molecule is regenerated to accept other acetic acid molecules and start the cycle over?
Oxaloacetate
28
Where does the electron transport chain occur?
Cristae of cell's mitochondria
29
What does the electron transport chain produce?
32 molecules of ATP
30
What is the function of the electron transport chain?
Energy is released by the transfer of electrons during a redox reaction involving oxygen
31
Water has ____ potential energy when held behind a dam, just as glucose molecules have _____ potential (chemical) energy
High; high
32
What type of process is cellular respiration?
Aerobic
33
What is produced at the bottom of the electron transport chain?
Water
34
What is produced as electrons move down the electron transport chain?
ATP
35
What happens to NADH and FADH2 in the electron transport chain?
They lose their electrons, oxidized to NAD+ and FAD and recycled back to glycolysis and the citric acid cycle
36
What happens during chemiosmosis?
A large concentration of H+ on one side results in high potential energy, then converted to kinetic energy
37
What happens during oxidative phosphorylation?
Spinning of ATP synthase adds a phosphate group to ADP forming ATP
38
What is fermentation?
The anaerobic conversion of food's chemical energy into ATP energy
39
What is a modified glycolysis stage?
Fermentation
40
What does lactic acid fermentation produce?
2 ATP
41
Is fermentation more or less efficient than cellular respiration and why?
Less due to the presence or absence of oxygen
42
What is very similar to lactic acid fermentation?
Alcohol fermentation, instead of arctic acid its ethanol and carbon dioxide being produced
43
What does photosynthesis do?
Converts solar energy into chemical energy of food molecules
44
What happens to carbon dioxide in photosynthesis?
It gains hydrogens and electrons and is reduced into glucose
45
Leaves are the what of photosynthesis?
Sites
46
What allows Co2 to enter a leaf and O2 to exit?
Pores called stomata
47
What cells are within the leaves containing abundant chloroplasts for photosynthesis?
Mesophyll
48
What form of energy is sunlight?
Electromagnetic
49
The _____ the wavelength, the _____ the energy
Shorter; greater
50
The color of an object is the wavelength of visible light _____ by the object
Reflect
51
What are chlorophyll molecules?
Pigments within chloroplasts that capture sunlight energy
52
What colors does chlorophyll absorb?
Violet, blue, yellow/orange/red
53
What are carotenoids?
Pigment molecules that absorb violet/blue/green wavelengths
54
What happens when a discrete quantity of light energy contacts a chlorophyll molecule?
One of the chlorophyll's electrons absorbs this light energy
55
How can energy be used to produce ATP and NADPH?
If an electron is "captured" in its high energy excited state
56
What is NADPH?
The coenzyme that accepts and carries electrons during photosynthesis
57
What are photosystems?
Protein complexes embedded in the thylakoid membranes of chlorplasts
58
Where do light reactions occur?
On thylakoid membranes of chlorplasts
59
What do light reactions require?
Sunlight and water
60
What do light reactions produce?
Oxygen, ATP, NADPH
61
Where does the Calvin Cycle occur?
In the stroma of chloroplasts
62
What does the Calvin Cycle require?
Carbon dioxide, ATP and NADPH produced during the light reactions
63
What does the Calvin Cycle produce?
Glucose
64
What is the Photosystem II?
Water-splitting photosystem
65
What is resoname?
Term for when sunlight is absorbed by a chlorophyll molecule causing its excited electron to "jump" from one chlorophyll molecule to another
66
Name for reaction center chlorophylls in photosystem II?
P680
67
What replaces the lost electron in light reactions?
Oxidation of water
68
What is released in light reactions?
Oxygen
69
What connects Photosystem II to Photosystem I?
Electron transport chain
70
What is chemiosmosis?
When large concentration gradients move across membranes
71
What causes kinetic energy to spin the ATP synthase enzyme synthesizing ATP?
Oxidative phosphorylation
72
What is Photosystem I?
NADH- producing photosystem
73
What is the reaction center chlorophylls called in Photosystem I?
P700
74
What happens to NADP+ in light reaction Photosystem I?
It is reduced to NADPH
75
What happens in a Calvin cycle?
Carbon enters the Calvin cycle as 3 molecules of CO2
76
What catalyzes the binding of 5-carbon acceptor molecules
Rubisco
77
How many carbons are formed by the Calvin cycle?
15
78
Glucose produced by photosynthesis is used as fuel during ______
Cellular respiration
79
Glucose produced by photosynthesis is stored as___
Starch
80
Glucose produced by photosynthesis is formed into ____ to build cell walls
Cellulose
81
Glucose produced by photosynthesis is consumed by ____
Heterotrophs
82
What happens in Water Use Efficiency?
Carbon dioxide is taken into a plant's leaves and oxygen exits a plant's leaves through stomata
83
What is the enzyme that brings CO2 into the Calvin cycle?
Rubsisco
84
What is photorespiration?
WUE being lowered due to rubisco not being efficient
85
What do plants in very dry hot environment do to increase WUE?
C4 Pathway, CAM Pathway
86
What happens in the C4 pathway?
CO2 is bound to PEPcase, transported to bundle sheath cells, undloaded undergoing Calvin cycle like normal but concentrated to where any effect of O2 is swamped out.
87
How does the C4 strategy increase WUE?
Efficiently utilizing all of the CO2
88
What does the CAM Pathway do?
Opens the stomata at night, less loss of H2O, storing PEPcase in central vacuole then going in the Calvin cycle
89
How does the CAM Pathway increase WUE?
By minimizing the amount of H2O lost
90
Why are most plants C3?
More energy is required for alt. pathways and benefits outweigh the costs for plants in hot dry environments
91
What is the chemical energy of food molecules generated by autotrophs during photosynthesis?
Primary Production
92
What is the energy source for all organisms in all ecosystems?
Primary production
93
NPP represents the biomass gained by an autotroph
Growth and Production
94
NPP is the energy left over for _____ by herbivores and decomposers
Consumption
95
What is NPP?
Net Primary Production
96
What is the dominant measure of productivity in an ecosystem?
NPP
97
What is controlled by climate in terrestrial ecosystems?
NPP
98
As temperature increases, NPP ____
Increases
99
As precipitation increases, NPP _____
Increases
100
NPP is controlled by _____ in aquatic ecosystems?
Nutrient availability
101
What limits NPP in lakes and ponds?
Phosphorus
102
The majority of energy in rivers and streams is derived from?
Terrestrial organic matter
103
What limits NPP in the open ocean?
Nitrogen and Iron
104
What is responsible for 54% of global NPP?
Terrestrial Ecosystems
105
What is responsible for 46% of global NPP?
Aquatic ecosystems
106
The highest rates of NPP on land occur in the _____
Tropics
107
____ have high temperatures and precipitation, leading to high rates of NPP
Tropical regions
108
_____ account for high levels of oceanic NPP relative to their limited areas
Coastal zones
109
What is home to a community of worms, clams, crabs, and sea stars?
Hydrothermal vents
110
What is detritus?
Dead organic matter
111
How do hydrothermal vent organisms obtain energy?
During chemosynthesis
112
What is chemosynthesis?
When prokaryotes use chemicals as high-energy electron donors to reduce CO2 into glucose
113
Food chains are _____ of trophic interactions
diagrammatic representations
114
Term for feeding relationships that link organisms in an ecosystem based on what they eat and what eats them?
Trophic interactions
115
What is consumed by decomposers during the process of decomposition?
Organic matter (detritus) and wastes (feces)
116
What flows through an exosystem?
Energy
117
What is the measure of how much chemical energy at one trophic level makes it to the next trophic level?
Trophic efficiency
118
Trophic efficiency consists of____, _____,_____
Consumption efficiency, assimilation efficiency, production efficiency
119
What measures how much energy at one trophic level is consumed by the next trophic level?
Consumption efficiency
120
All autotrophic energy may not be consumed by herbivores why?
The autotroph's chemical and physical defense
121
What is considered a nutrient-poor component?
Wood
122
What is considered a nutrient-rich component?
Leaves
123
What measured how much energy from one trophic level is incorporated into the next trophic level to be used for maintenance and defense?
Assimilation efficiency
124
Consumed energy that is not assimilated is lost as ____
Wastes (feces)
125
What efficiency is greater in carnivores than herbivores?
Assimilation efficiency
126
What does plant matter contain much of?
Indigestible material (cellulose and lignin)
127
What measures how much energy from one trophic level goes into the production of new biomass at the next trophic level?
Production efficiency
128
The assimilated energy that does not go toward production is lost as ____ during cellular respiration
Heat
129
What is greater in ectotherms than in endotherms?
Production efficiency
130
Why is production efficiency greater in ectotherms than in endotherms?
Endotherms generate much more metabolic heat
131
What does trophic efficiency consist of?
Consumption, assimilation, and production efficiency
132
What is the energy pyramid?
The amount of energy available to the organisms at each trophic level in a food chain
133
How much energy is lost at each trophic level?
90%
134
What are food webs?
Diagrams of the trophic interactions of an ecosystem?W
135
Which is more realistic, food webs or food chains?
Food webs
136
What increases alongside realism?
Complexity
137
Do organisms fit conveniently in one single trophic level but at multiple levels?
Not all of them fit into just one level
138
What is recycled within ecosystems?
Nutrients
139
What is the study of cycling nutrients?
Biogeochemistry
140
What are the 2 largest pools of water?
Oceans and water vapor in the atmosphere
141
How does water flux between oceans and water vapor?
By evaporation and precipitation
142
Water vapor above the ocean is transported above the land by way of?
Wind
143
Precipitation over land is balanced by?
Evaporation and transpiration
144
What transports water from the land back to the ocean?
Rivers, streams, and groundwater
145
What are the 2 largest pools of nitrogen?
Atmospheric nitrogen gas N2, and nitrogen within organisms (amino acids, nucleic acids, ATP)
146
How does Nitrogen flux between pools?
Nitrogen fixation
147
What type of cycle does nitrogen have?
Internal cycle
148
What are the 2 largest pools for phosphorus?
Rock and soi, and phosphorus within organisms (nucleic acids, ATP, plasma membranes, bones)
149
How is phosphorus supplies to the soil?
Decomposition
150
What are the 2 largest pools of carbon?
Atmospheric carbon dioxide (CO2) and the organic carbon within organisms
151
How does Carbon flux between pools? Photosynthesis and cellular respiration
Photosynthesis and cellular respiration
152
How does trapped carbon return to the atmosphere as CO2?
Coal, oil, and natural gas
153
What is reflected by Earth's surface?
Solar radiation
154
What is the main greenhouse gas?
CO2
155
What keeps Earth warm enough to support life?
Greenhouse effect
156
Excessive burning of what is adding to increased amounts of CO2 to the atmosphere?
Burning of fossil fuels and wood
157
What is reducing the number of plants that would remove atmospheric CO2 by way of photosynthesis?
Deforestation
158
What are the potential implications of global warming?
Melting polar ice- leads to rising sea levels- leads to flooding coastal areas
159
What will alter the distribution of ecosystems?
Climate change
160
How can global warming be mitigated in small scale?
Recycling, public transportation, planting a tree
161
How can global warming be mitigated on large scale?
Solar polar, hydrogen and nuclear power, geothermal energy
