AP Bio Exam 2 Flashcards
1
Q
Metabolism
A
The entirety of an organisms chemical reactions
2
Q
Metabolic Pathway
A
Starting molecule (A) -> Reaction 1 -> B …. -> D (product)
3
Q
Each reaction in a metabolic pathway is catalyzed by an
A
enzyme
4
Q
Catabolic
A
Releasing energy by breaking down complex molecules into simplier compounds
5
Q
Anabolic
A
Consumes energy to build complex molecules from simpler ones
6
Q
Biggest example of a catabolic pathway
A
Cellular respiration
(Sugar glucose and organic fuels are broken down in the presence of oxygen to carbon dioxide and water)
7
Q
Examples of anabolic pathways
A
synthesis of an amino acid from simpler molecules and synthesis of a protein from amino acids
8
Q
Energy
A
The ability to do work
9
Q
Kinetic energy
A
Energy of motion
10
Q
Thermal energy
A
Kinetic energy of random movement of atoms or molecules
11
Q
Heat
A
Thermal energy transfer from one object to another
12
Q
Light Energy
A
Harnessed in photosynthesis to perform work
13
Q
Potential energy
A
Energy possessed given a location or structure
13
Q
Chemical Energy
A
The potential energy available for release in a chemical reaction
13
Q
Recalling that catabolic pathways release energy from breaking down complex molecule, glucose is
A
high in chemical energy
14
Q
Thermodynamics
A
Study of energy transformations
15
Q
Isolated system
A
Unable to exchange either energy or matter with its surroundings as a opposed to open systems
16
Q
Are organisms isolated or open systems?
A
Open: they absorb energy (light, chemical) and release energy (heat, metabolic waste)
17
Q
First Law of Thermodynamics (Principle of Conservation of Energy)
A
Energy can be transferred and transformed, but it cannot be created or destroyed
18
Q
Second Law of Thermodynamics
A
Every energy transfer or transformation increases the entropy of the universe
19
Q
Every time an energy transfer occurs
A
the universe becomes more disordered
20
Q
Entropy
A
A measure of molecular disorder or randomness
21
Q
The more randomly arranged a collection of matter is
A
The greater the entropy
22
Q
Spontaneous Reaction
A
A process that leads to an increase of entropy, thus can proceed without requiring an input of energy
23
Spontaneous =
energetically favorable (NOT will occur rapidly)
24
Examples of spontaneous reactions
explosions, rusting
25
Nonspontaneous
A process that leads to a decrease in entropy. requires energy
26
Water flowing downhill is ________
Water flowing uphill is ________
spontaneous
non-spontaneous
27
The universe is really just
the system + the surroundings
28
Free energy (G)
The portion of a system's energy that can perform work when temperature and pressure are uniform throughout the system
29
Equation for the change in free energy
ΔG = ΔH - TΔS
30
ΔH
Change in Enthalpy (total energy)
31
ΔS
Change in entropy
32
T
Absolute temperature (in units K)
33
-ΔG
Spontaneous
(Gives up enthalpy and H decreases) or (TΔS increases) or both
34
Verbally explain -ΔG
Spontaneous processes decreases the system's free energy
35
+ ΔG
Nonspontaneous
36
Verbally explain +ΔG
Nonspontaneous reactions increases the system's free energy
37
Free energy is like a
measure of a system's instability
38
Unstable systems (higher G) tends to change to become
more stable (lower G)
39
Name three examples of how unstable systems become more stable
Gravitational motion (Diver goes from higher to lower altitude)
Diffusion (Molecules of dye disperse)
Chemical Reaction (Glucose is broken down into simpler molecules)
40
Exergonic Reaction
net release of free energy (-ΔG)
41
Endergonic Reaction
Absorbs free energy from its surroundings (+ΔG)
42
Why is metabolism fundamental to life's...uh...lifeness
It is never at equilibrium!
43
Energy Coupling
Use of exergonic processes to drive an endergonic one
44
ATP + H2O ->
How much G is released?
ADP + Pi
ΔG = -7.3 kcal/mol per mol of ATP
45
Enzyme
A macromolecule (usually proteins here) that acts as a catalyst
46
Catalyst
A chemical agent that speeds up a reaction without being consumed by the reaction
47
Activation Energy (E sub A)
The initial investment of energy to start a reaction
48
Enzymes cannot
change the ΔG of a reaction (make a endergonic reaction exergonic)
49
Suffix of enzyme name
-ase
50
Enzyme-substrate complex
When and enzyme binds to its substrate
51
Active Site
Location (usually a pocket or groove) where substrate binds to the enzyme
52
How can unideal conditions affect an enzymes efficiency?
Temperatures and pH's outside the ideal for an enzyme can disrupt the bonds between its molecules, thus misshaping the enzyme and its active site
53
Cofactors
Non-protein enzyme helpers (can be inorganic or organic)
ex. zinc, iron, copper
54
Coenzyme
Organic cofactor
ex. Vitamins
55
Competitive Inhibitor
Reduce productivity of enzymes by blocking substrates from entering active sites
56
Noncompetitive inhibitor
Binds in different location of enzyme but this interaction causes the enzyme to change shape
57
Allosteric Regulation
Any case where a protein's function at one site is affected by the binding of a regulatory molecule to a separate site. Can result in either inhibition or stimulation of activity.
58
Feedback Inhibition
A metabolic pathway is halted by the inhibitory binding of its end products to an enzyme that acts early in the pathway
59
Fermentation
A partial degradation of sugars that occurs without O2
60
Aerobic respiration
Consumes organic molecules and O2 and yields ATP
61
Which is more efficient? Aerobic respiration or fermentation?
Aerobic respiration
62
Anaerobic respiration
Similar to aerobic respiration but consumes
compounds other than O2
63
Cellular Respiration includes what respirations
both aerobic and anaerobic respiration but is often used to refer to aerobic respiration
64
Aerobic Respiration Summarized Equation
Organic Compound + Oxygen -> CO2 + Water + Energy
65
Cellular Respiration Equation
C6H12O6 + 6O2 -> 6CO2 + 6H2O + Energy (ATP + heat)
66
Obligate Anaerobes
Only function via anaerobic respiration
67
Facultative Anaerobes
An organism that makes ATP by aerobic respiration if oxygen is present, but is capable of switching to fermentation if oxygen is absent.
68
Redox Reactions
Reaction where electrons are transferred between reactants (with exceptions)
69
Oxidation
Loss of electrons
70
Reduction
Addition of electrons
71
Reducing Agent
Electron donor
72
Oxidizing Agent
Electron acceptor
73
Energy can't be released all at once in order to be efficient
If a gasoline tank explodes, it can't drive the car very far
74
NAD+
A coenzyme that accepts electrons to become the reduced form NADH (becomes an oxidizing agent)
75
FAD
A coenzyme that accepts electrons to become the reduced form FADH2 (becomes an oxidizing agent)
76
What is the electron transport chain made of?
A number of molecules, mostly proteins, built into the inner membrane of the mitochondria of eukaryotic cells
77
Summary of electron transport chain
Electrons removed by glucose and placed into NADH and are transferred eventually to O2 along with hydrogen nuclei (H+) forming water
78
Three stages of cellular respiration
1. Glycolysis
2. Pyruvate oxidation and the citric acid cycle
3. Oxidative Phosphorylation
79
Glycolysis
(where does it occur?)
Degradation process by breaking glucose into two pyruvate molecules. Located in the cytosol.
80
Citric Acid Cycle
(Where does it occur?)
Breakdown of glucose to carbon dioxide is completed. Located in mitochondrion. (in prokaryotes located in cytosol)
81
Pyruvate Oxidation
(Where does it occur?)
Pyruvate oxidizes into acetyl CoA. Located in mitochondrion.
82
Oxidative Phosphorylation
Electron transport chain accepts electrons from coenzymes. Electrons are combined with molecular oxygen and hydrogen ions forming water. Energy released at each step of the chain is stored for the mitochondrion to make ATP from ADP.
83
Inputs and Outputs of Glycolysis
Input: Glucose, 2 NAD+, 2 ATP
Output: 2 pyruvate, 2 H2O, 2 NADH + 2H+, 2 ATP (remember 2 ATP were used)
84
Inputs and Outputs of Pyruvate Oxidation
Input: 2 Pyruvate, 2 NAD+
Output: 2 NADH + H+, CO2, 2 Acetyl CoA
85
Inputs and Outputs of Citric Acid Cycle
Input: 2 Acetyl CoA, 2 Oxaloacetate
Output: 2 ATP, 8 NADH, 6 CO2, 2 FADH2
86
Two stages of oxidative phosphorylation
1. Electron Transport Chain
2. Chemiosmosis
87
Two stages of glycolysis
1. Energy investment phase (Spends ATP)
2. Energy payoff phase (ATP is produced)
88
Does glycolysis require oxygen?
No, but the energy stored in pyruvate and NADH can be extracted in further steps of cellular respiration which require oxygen
89
Does pyruvate oxidation require oxygen?
Yes
90
Does the citric acid cycle require oxygen?
Yes
91
Cytochromes
The proteins in which electrons are passed down to O2 during oxidative phosphorylation
92
ATP synthase
Enzyme that makes ATP from ADP and inorganic phosphate
93
What is ATP synthase powered by?
The proton-motive force: H+ ions
94
Is NADH or FADH2 higher in potential energy?
NADH
95
Chloroplasts
Organelles that capture light energy and do photosynthesis
96
Autotrophs
Sustain themselves without eating anything derived from other living beings
97
Heterotrophs
Obtain organic material by second major mode of nutrition
98
Mesophyll
Tissue in the interior of a leaf
99
Stomata
Microscopic pores by which CO2 enters the leaf and oxygen exits
100
Stroma
Dense interior fluid of a chloroplast
101
Chlorophyll
Green pigment in chloroplasts
102
Thylakoids
Sacs that hold chlorophyll
103
Grana
Stacked thylakoids
104
Which wavelengths of light are optimal for photosynthesis?
Chlorophyll a: violet-blue and red light work best for photosynthesis
Chlorophyll b: Blue and a little red (but its more of an accessory pigment to broaden spectrum)
Overall: Blue (400-450 nm) and red (650-700 nm)
105
Photosynthesis Equation
6 CO2 + 12 H2O + Light Energy -> C6H12O6 + 6O2 + 6 H2O
SIMPLIFIED
Light energy + 6 CO2 + 6 H2O -> C6H12O6 + 6 O2
106
Why is the splitting of water in photosynthesis important?
It creates hydrogen and oxygen incorporating the electrons of hydrogen into sugar molecules and releasing oxygen as a by product
107
Two stages of photosynthesis
1. Light Phases (photo)
2. Calvin Cycle (synthesis)
108
Light Reactions
Convert solar energy into chemical energy
109
NADP+ role in photosynthesis
Reduce to NADPH and store electrons
110
Phosphorylation
Generate ATP from ADP by adding a phosphate group
111
Phases of Calvin Cycle
1. Carbon Fixation
2. Reduction
3. Regeneration of the CO2 acceptor
112
Where do light reactions occur?
Thylakoids
113
Where does the Calvin cycle occur
Stroma
114
C3 plants
115
Compare and contrast photosynthesis and cellular respiration
Both generate ATP by chemiosmosis but use
different sources of energy (Chemical energy from food vs. light energy)
In mitochondria, protons are pumped to the intermembrane space and drive
ATP synthesis as they diffuse back into the mitochondrial matrix
In chloroplasts, protons are pumped into the thylakoid space and drive ATP
synthesis as they diffuse back into the stroma
116
Phase 1: Carbon Fixation
Involves the incorporation of the CO2 molecules into ribulose bisphosphate (RuBP) using the enzyme rubisco
117
Phase 2: Reduction
Involves the
reduction and phosphorylation of
3-phosphoglycerate to G3P
118
Phase 3: Regeneration
Involves the rearrangement
of G3P to regenerate the initial CO2 receptor, RuBP
119
C3 Plants
Follows standard photorespiration. initial product is 3-phosphoglycerate
120
C4 Plants
Minimize the cost of photorespiration by incorporating CO2 into
a four-carbon compound
121
CAM plants
Open their stomata at night, incorporating CO2 into organic
acids
122
lactic acid fermentation
pyruvate is reduced by NADH, forming lactate as an end product, with no release of CO2
123
alcohol fermentation
pyruvate is converted to ethanol in two steps
124
Fermentation consists of
glycolysis plus reactions that regenerate NAD+, which can be reused by glycolysis
