Chap 4 The Energy of Life Flashcards
(127 cards)
1
Q
What is energy?
A
the ability to do work
2
Q
What are the different forms of energy?
A
kinetic
potential
3
Q
What is kinetic energy?
A
energy in motion/movement
4
Q
What is potential energy?
A
stored energy that is available to do work
5
Q
Can energy be converted from one form to another?
A
yes
6
Q
What is the first law of thermodynamics?
A
energy is never created or destroyed
7
Q
What it entropy?
A
a measure of disorder/the randomness of the universe
8
Q
What is the second law of thermodynamics?
A
the entropy of the universe is increasing
9
Q
Why is the entropy of the universe increasing?
A
heat energy is constantly being lost and heat energy is disordered
10
Q
What does a chemical rxn do?
A
rearranges atoms (break/forms bonds)
11
Q
What is metabolism?
A
all chemical rxns in cells
12
Q
In a chemical rxn does it need or release energy when forming a bond?
A
needs energy
13
Q
In a chemical rxn does it need or release energy when breaking bonds?
A
release energy
14
Q
Where is the energy in a compound stored?
A
in the chemical bonds
15
Q
Most energy transformations in organisms occur in what way?
A
oxidation-reduction rxns
16
Q
What is oxidation-reduction rxn?
A
transfer of electrons
17
Q
What is oxidation?
A
atom lose electron
18
Q
What is reduction?
A
atom gains electron
19
Q
What is an electron transport chain?
A
series of membrane proteins participating in sequential, linked redox rxns
20
Q
How much energy is released from redox reactions?
A
a small amount
21
Q
Photosynthesis and respiration both use what?
A
electron transport chain
22
Q
What happens to the energy released from the electron transport chain?
A
cells store it and use it in other rxns
23
Q
What is ATP?
A
adenosine triphosphate - a nucleotide that temporarily stores energy
24
Q
What is the cellular currency?
A
ATP
25
What is the form of energy that cells can use?
ATP
26
What type of energy is stored in ATP?
potential
27
What does ATP do?
releases stored energy
28
How does ATP release energy?
removing the endmost phosphate group by hydrolysis
29
What does the cell use the energy for?
to do work
30
ATP if formed during what?
cellular respiration
31
What is cellular respiration?
chemical rxns that release energy from sugar producing ATP from ADP
32
ATP is coupled with what?
chemical rxns
33
Reactions that break down ATP are couples with what?
rxns that require energy input
34
What happens when rxns are coupled together?
energy released from ATP can power the second rxn
35
What do enzymes do in a chemical rxn?
covert reactants into products
36
In relation to enzymes what is a substrate?
what enzymes act on
37
In relation to enzymes what are reactants?
molecules present at the start of the reaction
38
In relation to enzymes what are products?
molecules present at the end of the reaction
39
What do enzymes do to the energy in a rxn?
lower the activation energy
40
What is the activation energy of a rxn?
the energy required to start a reaction
41
Without enzymes the activation energy is...?
high
42
How is the activation energy lowered?
when an enzyme binds to the substrate the activation energy is lowered
43
Does temperature affect enzyme activity?
yes
44
During what temperature range are enzymes active?
55-79 degrees C
| is the optimal temperature range
45
Do chemical factors affect enzyme activity?
yes
46
Where do substances enter/exit a cell?
through the membrane
47
Membranes form what in cells?
barriers
48
Solutes can enter/exit depending on what two factors?
concentration gradients
the chemical nature of the substance (polarity, charge, size)
49
What is a "gradient"
concentration difference
50
What happens when there is a gradient?
molecules diffuse until there is no more concentration gradient
51
maintaining a concentration gradient requires...?
energy
52
Is a gradient more ordered or less ordered?
more ordered (less entropy)
53
Is no gradient more or less ordered?
less ordered (more entropy)
54
Entropy tends to what?
increase
55
Simple diffusion does not require what?
energy
56
Simple diffusion is a type of what?
passive transport
57
When does simple diffusion occur?
when there is a concentration difference on one side of a membrane compared to the other
58
How do molecules diffuse?
from high concentration to low concentration
59
Osmosis does not require what?
energy
60
Osmosis is a type of what?
passive transport
61
Osmosis takes place when...?
there is a different concentration of water on one side of a selectively permeable membrane compared to the other
62
What determines the water content in animal cells?
osmosis
63
How does water move in and out of cells?
osmosis
64
Facilitated diffusion does not require what?
energy
65
Passive transport includes what?
facilitated diffusion
66
When does facilitated diffusion occur?
when membrane proteins transport substances across a cell membrane
67
Facilitated diffusion requires what?
membrane proteins
68
Active transport requires what?
energy
69
Active transport occurs when?
membrane proteins use cellular energy to transport substances across a cell membrane
70
The membrane transport protein is referred to as what?
a pump
71
With active transport how are substances moved?
up their concentration gradient
72
How are ions moved against their gradient?
the sodium-potassium pump
73
Where are the "pump" protein found?
the membranes of neuron and muscle cells
74
How do small nonpolar molecules enter/exit a cell?
passively diffuse across the membrane when there is a concentration gradient (simple diffusion e.g. osmosis and facilitated diffusion)
75
How to large polar molecules enter/exit a cell?
active transport into the cell regardless of gradient (membrane protein pumps)
76
Photosynthesis produces what?
sugar
77
Explain the photosynthesis rxn?
uses light energy and CO2 from the air to form glucose C6H12O6 and other carbohydrates
78
Sugar is a crucial what?
food source
79
How is sugar used?
in cellular respiration to make ATP for cells to use
80
What powers photosynthesis?
sunlight
81
What do photosynthetic organisms need to make their own sugar?
sunlight
CO2
water
82
Photons are what?
packets of light energy
83
Photosynthesizers capture photons of what?
visible light
84
What is the main photosynthetic pigment in plants?
chlorophyll a
85
Pigment does what?
absorbs energy from some wavelengths of light and reflects other wavelengths
86
What type of cells contain chloroplasts
mesophyll
87
Most photosynthetic cells contain how many chloroplasts?
40-200
88
Where does photosynthesis take place in eukaryotes?
chloroplasts
89
In how many stages does photosynthesis occur?
2 - Light rxns
| - Carbon rxns
90
What happens in the light rxn of photosynthesis?
light energy is captured and converted to chemical energy
91
What happens in the carbon rxns of photosynthesis?
energy is used to produce sugar
92
Where does the light rxn in photosynthesis occur?
thylakoids
93
The light rxn in photosynthesis required what?
water
| light
94
What is produced in the light rxn of photosynthesis?
ATP
| NADPH (to carry and store energy)
95
What is formed as a byproduct of the light rxn of photosynthesis?
oxygen gas
96
What do the carbon rxns do in photosynthesis?
carbohydrates
97
What is the name for the carbon rxns in photosynthesis?
calvin cycle
98
Where do the carbon rxns in photosynthesis occur?
the stroma (liquid filled space in the chloroplasts)
99
What powers the calvin cycle?
ATP and NADPH
100
What does the calvin cycle do?
assembles CO2 molecules into carbohydrates
101
What do plants use sugar for?
respiration to make ATP
build complex sugars/polysaccharides
102
Plants use different what?
carbon fixation pathways
103
Carbon fixation pathways are plant what?
adaptations
104
What type of plants do well in cool moist weather?
C3
105
What type of plants do well in hot dry weather?
C4
| CAM
106
Organisms need what?
food
| oxygen
107
Cells use energy in food to make what?
ATP
108
What would happen to cells without ATP?
they would die
109
What is the process that makes ATP?
cellular respiration
110
What is the form of energy cells are able to use?
ATP
111
What do cells use ATP for?
do work
| power chemical rxns
112
Aerobic cellular respiration is a series of what?
chemical rxns
113
What are the reactants of aerobic cellular respiration?
glucose
| oxygen
114
What are the products of aerobic cellular respiration?
CO2
water
ATP
115
Why do we need to breathe air?
it is required for cellular respiration
116
Where does oxygen travel to when we breathe?
Mitochondria
117
What exits the mitochondria during cellular respiration?
CO2
118
What are the three main pathways for cellular respiration?
Glycolysis
Krebs cycle
electron transport chain (ETC)
119
What happens in glycolysis?
glucose in split in half forming pyruvate. some energy is transferred to electrons, some used to form ATP
120
What happens in the Krebs Cycle?
a derivative of pyruvate is oxidized, CO2 is released. more energy is transferred to electrons
121
What happens in the electron transport chain?
energy from electrons id used to form ATP.
122
What is the final electron acceptor in cellular respiration?
oxygen
123
Cellular respiration relies on what type of reactions?
redox
124
What do the pathways of aerobic respiration do?
release energy by oxidizing glucose and reducing oxygen
125
Where is the most ATP produced?
mitochondria
126
What are the key ATP-generating processes?
krebs cycle
| electron transport chain
127
Does the redox respiration rxn release or take up energy?
release energy
