AP BIO UNIT 3 Flashcards

1
Q

Metabolism

A

All of the chemical reactions in an organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Metabolic Pathways

A

Series of chemical reactions that either build complex molecules or break down complex molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Catabolic Pathway

A

Pathways that release energy by breaking down complex molecules into simpler compounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Anabolic Pathway

A

Pathways that consume energy to build complicated molecules from simpler compounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Energy

A

The ability to do work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Organisms need energy to…

A

survive and function. A loss in energy flow results in death.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Kinetic Energy

A

Energy associated with motion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Thermal Energy

A

Energy associated with the movement of atoms or molecules.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Potential Energy

A

Stored energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Chemical Energy

A

Potential energy available for release in a chemical reaction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Thermodynamics

A

The study of energy transformations in matter. These laws apply to the universe as a whole.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

1st Law of Thermodynamics

A

Energy cannot be created or destroyed. Energy CAN be transferred or transformed. (Example: the chemical energy (potential) stored in the nut will be transformed into kinetic energy for the squirrel to climb the tree.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

2nd Law of Thermodynamics

A

Energy transformation increases the entropy (disorder) of the universe. During energy transfers or transformations, some energy is unusable and often lost as heat. (Example: as the squirrel climbs the tree, some energy is released as heat)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

∆G

A

Change in free energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

∆H

A

Change in total energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

T

A

Absolute temperature (K)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

∆S

A

Change in entropy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Law of Thermodynamics Formula

A

∆G = ∆H - T∆S

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Exergonic Reactions

A

Reactions that release energy (Example: cellular respiration)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Endergonic Reactions

A

Reactions that absorb energy (Example: photosynthesis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Mechanical Work

A

Movement (Example: beating cilia, movement of chromosomes, contraction of muscle cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Transport Work

A

Pumping substances across membranes against spontaneous movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Chemical Work

A

Synthesis of molecules (Example: building polymers from monomers)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

ATP

A

(Adenosine Triphosphate) Molecules that organisms use as a source of energy to perform work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Organisms obtain energy...
By breaking the bond between the 2nd and 3rd phosphate in a hydrolysis reaction. (ATP --> ADP)
26
Phosphorylation
The released phosphate moves to another molecule to give energy
27
Regeneration of ATP
ADP can be regenerated to ATP via the ATP cycle. (ATP + H20 --> ADP + Pi)
28
Enzymes
Macromolecules that catalyze (speed up) reactions by lowering the activation energy. (Are not consumed by the reaction, type of protein, enzyme names end in "ase")
29
Enzyme Structure
The enzyme acts on a reactant called a substrate
30
Active Site
Area for substrate to bind
31
Enzyme Function
Active site is open, substrates are held in active site by weak interactions, substrates are converted to products, products are released.
32
Induced Fit
Enzymes will change shape of their active site to allow the substrate to bind better.
33
Enzyme Catabolism
Enzyme helps break down complex molecules.
34
Enzyme Anabolism
Enzyme helps build complex molecules.
35
Effects on Enzymes
Enzymes are proteins, which means their 3D shape can be affected by different factors.
36
Factors that Affect the Efficiency of Enzymes
Temperature, pH, Chemicals
37
Optimal Conditions
The conditions (temperature & pH) that allow enzymes to function optimally.
38
Enzyme Activity (Temperature)
The rate of enzyme activity increases with temperature (due to collision) up to a certain point). After a certain point, the enzyme will denature.
39
Enzyme Activity (pH)
Enzymes function best at a specific pH. Being outside the normal pH range can cause hydrogen bonds to break changing the shape of the enzyme.
40
Enzyme Cofactors
Non-protein molecules that assist enzyme function. Inorganic cofactors consist of metals. Can be bound loosely or tightly.
41
Holoenzyme
An enzyme with the cofactor attached.
42
Coenzymes
Organic cofactors. (Example: vitamins)
43
Enzyme Inhibitors
Reduce the activity of specific enzymes.
44
Permanent Inhibition
Inhibitor binds with covalent bonds. (Example: toxins and poisons)
45
Reversible Inhibition
Inhibitor binds with weak interactions.
46
Competitive Inhibitors
Reduce enzyme activity by blocking substrates from binding to the active sites. Inhibition can be reverse with increased substrate concentrations.
47
Noncompetitive Inhibitors
Bind to the area other than the active site (allosteric site), which changes the shape of the active site preventing substrates from binding.
48
Regulation of Chemical Reactions
A cell must be able to regulate its metabolic pathways. Control where and when enzymes are active. Switch genes that code for enzymes on or off.
49
Allosteric Enzymes
Allosteric enzymes have two binding sites. 1 active site, 1 allosteric site (regulatory site, site other than the active site)
50
Allosteric Regulation
Molecules bind (noncovalent interactions) to an allosteric site which changes the shape & functions of the active site. May result in inhibition (by an inhibitor) or a stimulation (by an activator) of the enzymes activity.
51
Allosteric Activator
Substrate binds to allosteric site & stablilizes the shape of the enzyme that the active sites remain open.
52
Allosteric Inhibitor
Substrate binds to allosteric site and stabilizes the enzyme shape so that the active sites are closed (inactive form).
53
Cooperativity
Substrate binds to one active site (on an enzyme with more that one active site) which stabilizes the active form. Considered allosteric regulation since binding t one site changes the shape of other sites.
54
Feedback Inhibition
Sometimes, the end product of a metabolic pathway can act as an inhibitor to an early enzyme in the same pathway.
55
Photosynthesis
The conversion of light energy to chemical energy. (Plants are autotrophs (photoautotrophs))
56
Autotrophs
Organisms that produce their own food (organic molecules) from surrounding simple substances
57
Heterotrophs
Organisms unable to make their own food so they live off of other organisms
58
Evolution of Photosynthesis
Photosynthesis first evolved in prokaryotic organisms.
59
Cyanobacteria
Early prokaryotes capable of photosynthesis. Oxygenated the atmosphere of early Earth. Prokaryotic photosynthetic pathways were the foundation of eukaryotic photosynthesis.
60
Site of Photosynthesis
Leaves are the primary location of photosynthesis in most plants.
61
Chloroplast
Organelle or the location of photosynthesis. Found in the mesophyll, the cells that make up the interior tissue of the leaf
62
Stomata
Pores in leaves that allow CO2 in and O2 out
63
Chloroplasts are surrounded by a
double membrane
64
Stroma
Aqueous internal fluid
65
Thylakoids
Form stacks known as grana
66
Chlorophyll
Green pigment in the thylakoid membranes
67
Photosynthesis Formula
6 CO2 + 6 H2O + Light Energy --> C6H12O6 + 6 O2
68
Photosynthesis Reactants
6 CO2 + 12 H2O
69
Photosynthesis Products
C6H12O6 + 6 H2O + 6 O2
70
Redox Reactions
Reaction involving complete or partial transfer of one or more electrons from one reactant to another.
71
Redox Reactions in Photosynthesis
The electrons are transferred with H+ (from split H2O) to CO2 reducing it to sugar
72
Oxidation
Loss of e-
73
Reduction
Gain of e-
74
Two Stages of Photosynthesis
Light Reactions and the Calvin Cycle
75
Light
Electromagnetic energy. Made up of particles of energy called photons. Travel in ways.
76
Wavelength
The distance from the crest of one wave to the the crest of the next. The entire range is known as the electromagnetic spectrum. 380 nm to 750 nm is visible light.
77
Short Wavelengths
Higher energy
78
Long Wavelengths
Lower energy
79
When light interacts with matter it can be...
Reflected, transmitted, or absorbed. Pigments are able to absorb visible light. The color we see is the reflected wavelengths. Leaves are green because chlorophyll ABSORBS violet-blue and red light, and reflects green
80
Chlorophyll A
Primary pigment, involved in light reactions, blue/green pigment, absorb purple/blue/red, reflects blue/green.
81
Chlorophyll B
Accessory pigment, yellow/green pigment, absorbs blue
82
Carotenoids
Broaden the spectrum of colors that drive photosynthesis. Yellow/orange pigment.
83
Photoprotection
Carotenoids absorb and dissipate excessive light energy that could damage chlorophyll or interact with oxygen.
84
The Light Reactions Overview
Occur in the thylakoid membrane in the photosystems. Convert solar energy to chemical energy.
85
2 Forms of Chemical Energy
NADPH & ATP. The cell accomplishes this conversion by using light energy (photons) to excite electrons.
86
Light & Chlorophyll
Chlorophyll absorbs a photon of light. E- is boosted from a ground state to an excited state. E- is unstables. Falls back to ground state. Releases energy as heat. Emits photons as fluorescence.
87
Photosystems
Reaction center and light capturing complexes
88
Reaction Center
A complex of proteins associated with chlorophyll A and an electron acceptor.
89
Light Capturing Complexes
Pigments associated with proteins. THINK: antenna for the reaction centers.
90
Photosystem II
Reaction center P680. Absorbs light at 680 nm.
91
Photosystem I
Reaction center P700. Absorbs light at 700 nm.
92
Inside PS II
Light energy (photon) causes an e- to go from an excited state back to a ground state. This repeats until it reaches P680 pair of chlorophyll A molecules. The e- is transferred to a primary e- acceptor, forming P680+. H2O is split into 2e- reduced P680 +, 2H+ released into thylakoid space, 1 oxygen atom (which immediately bonds to another oxygen atom). Linear electron flow: each excited electron will pass from PSII to PSI via the electron transport chain.
93
Generation of ATP
The "fall" of electrons from PS II to PS I provides energy to form ATP. THe H+ gradient is a form of potential energy. ATP synthase couples the diffusion of H+ to the formation of ATP.
94
Inside PS I
LIght energy excites electrons i the P700 chlorophyll molecules. Become P700+. Electrons go down a second transport chain. NADP+ reductase catalyzes the transfer of e- from Fd to NADP+.
95
Light Reaction Inputs
H2O, ADP, NADP+
96
Light Reaction Outputs
O2, ATP, NADPH
97
Light Reactions Summary
Converts solar energy to chemical energy. Chemical energy is in 2 forms: NADPH and ATP. Water is split. Provides a source of electrons and protons (H+). Releases O2 as a by-product. Light absorbed by chlorophyll drives the transfer of electrons and hydrogen ions from H2O to an electron acceptor called NADP+. NADP+ is reduced to NADP. Generates ATP by phosphorylating ADP.
98
Calvin Cycle
The Calvin Cycle is cyclic electron flow. Uses ATP and NADH to reduce CO2 to sugar G3P. For net synthesis of 1 G3P molecule, the cycle must take place 3 times.
99
Three Phases of the Calvin Cycle
1. Carbon Fixation 2. Reduction 3. Regeneration of RuBP
100
Carbon Fixation
CO2 is incorporated into the Calvin Cycle on at a time. Each CO2 attaches to a molecule of RuBP. Catalyzed by the enzyme rubisco. Form 3-phosphoglycerate.
101
Reduction
Each molecule of 3-phosphoglycerate is phosphorylated by ATP (uses 6 total). Becomes 1, 3-biphosphoglycerate. 6 NADPH molecules donate electrons to 1, 3-biphosphoglycerate. Reduces to G3P. 6 molecules of 63P are formed, but only one is counted as a net gain. The other 5 G3P molecules are used to regenerate RuBP.
102
Regeneration of RuBP
5 G3P molecules are used to regenerate 3 molecules of RuBP. Uses 3 ATP for regeneration. Cycle is now ready to take CO2 again.
103
Calvin Cycle Input
3 CO2, 9 ATP, 6 NADPH
104
Calvin Cycle Output
1G3P*, 9 ADP, 6 NADP+
105
Calvin Cycle Summary
Uses NADPH, ATP, and CO2. Produces a 3-C sugar G3P. Three Phases: Carbon Fixation, Reduction, Regeneration of RuBP.
106
Photorespiration
On very hot days plants close their stomata to stop water loss. Causes less CO2 to be present and more O2. Rubisco binds to O2 and uses ATP. The process produces CO2. No sugar is produced. BAD for the plant.
107
C4 Plant Adaptations
Spatial separation of steps, stomata partially closed to conserve water. Mesophyll cells fix CO2 into a 4-C molecule. Transferred to a bundle sheath cells. Releases CO2 to be used in the Calvin Cycle. (Examples: Maize, Grasses, Sugarcane)
108
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. (Examples: Pineapples, Cacti, Succulents, Jade)
109
Cellular Respiration
Cells harvest chemical energy stored in organic molecules and use it to generate ATP. Organic molecules + oxygen (CO2 + H2O + energy). Starch is the major source of fuel for animals. Breaks down into glucose. The oxidation of glucose transfers e- to a lower energy state, releasing energy to be used in ATP synthesis.
110
Path of Electrons in Energy Harvest
glucose --> NADH --> ETC --> Oxygen
111
Energy Harvest
Glucose is broken down in steps to harvest energy. Electrons are taken from glucose at different steps. Each e- taken travels with a proton (H+). Dehydrogenase take 2e- & 2 protons from glucose. Oxidizing agent for glucose. Transfers 2e- & 1 proton to the coenzyme NAD+. Reduces to NADPH (stores energy). Other proton is released into surrounding solution as H+. NADH carries e- to the electron transport chain.
112
Electron Transport Chain (ETC) (Photosynthesis)
A sequence of membrane proteins that shuttle electrons down a series of redox reactions. Releases energy used to make ATP. ETC transfers e- to O2, the final e- acceptor, to make H2O. Releases energy.
113
Three Stages of Cellular Respirtion
1. Glycolysis 2. Pyruvate Oxidation 3. Oxidative Phosphorylation (ETC & Chemiosmosis)
114
Glycolysis
Starting point of cellular respiration. Occurs in the cytosol. Splits glucose (6C) into 2 pyruvates (3C).
115
Energy Investment Stage (CR)
The cell uses ATP to phosphorylate compounds of glucose. (2 ATP --> 2 ADP + P)
116
Energy Payoff Stage (CR)
Energy is produced by substrate level phosphorylation. Net energy yield per glucose: 2 ATP & NADH. (4 ADP + P --> 4 ATP) (2 NAD+ + 4e- + 4H+ --> 2 NADH + 2H+)
117
Net Glycolysis
2 Pyruvate + 2H2O 2 ATP 2 NADPH + 2H+
118
Pyruvate Oxidation and Citric Acid Cycle
If oxygen is present, the pyruvate enters the mitochondria (eukaryotic cells). Pyruvate is oxidized into Acetyl CoA. Acetyl CoA is used to make citrate in the citric acid cycle. 2 CO2 & 2 NADH are produced).
119
Pyruvate Oxidation
pyruvate --> acetyl CoA
120
Citric Acid Cycle
Also known as the Krebs Cycle. Occurs in the mitochondrial matrix. Turns acetyl CoA into citrate. Releases CO2. ATP is synthesized. Electrons transferred to NADH & FADH2).
121
Citric Acid Cycle Inputs
2 Acetyl CoA
122
Citric Acid Cycle Outputs
2 ATP, 6 NADH, 4 CO2, 2 FADH2
123
Oxidative Phosphorylation
Consists of ETC and Chemiosmosis
124
Electron Transport Chain (ETC) (Cellular Respiration)
The ETC is located in the inner membrane of the mitochondria. Collection of proteins, As the electrons "fall" proteins alternate between reduced (accepts e-) and oxidized (donates e- state). The cristae increase the surface area for the reactions to occur. Does not produce ATP directly. Helps manage the release of energy by creating several small steps for the "fall" of electrons. The final electron acceptor is oxygen. Each oxygen pairs with 2H+ and 2e- to form H2O. One major function of the ETC is to create a proton (H+) gradient across the membrane. As proteins shuttle electrons along the ETC, they also pump H+ into the intermembrane space. Use the exergonic flow of electrons from NADH and FADH2. This gradient will power chemiosmosis. Use hydrogen ions to power cellular work.
125
Chemiosmosis
ATP synthase: the enzyme that makes ATP from ADP + P. Uses energy from the H+ gradient across the membrane. H+ ions flow down their gradient through ATP synthase. ATP synthase acts like a rotor. When H+ binds, the rotor spins. Acivates catalytic sites to turn ADP + P into ATP. Produces about 26-28 ATP per glucose.
126
Cellular Respiration Summary
Glycolysis - Input: 1 Glucose Output: 2 Pyruvate, 2 ATP, 2 NADH Pyruvate Oxidation - Input: 2 Pyruvate Output: 2 Acetyl CoA, 2 CO2, 2 NADH Citric Acid Cycle - Input: 2 Acetyl CoA Output: 4 CO2, 2 FADH2, 2 ATP, 6 NADH Oxidative Phosphorylation - Input: 10 NADH, 2 FADH2 Output: 26-28 ATP Total Output - 30 - 32 ATP
127
How do organisms produce ATP in the absence of oxygen?
Anaerobic Respiration Fermentation
128
Anaerobic Respiration
Generates ATP using electron receptors in the absence of oxygen. Takes place n prokaryotic organisms that live in environments with no oxygen. The final electron acceptors are sulfates or nitrates.
129
Fermentation
Generates ATP without an ETC. Extension of glycolysis. Recycles NAD+, occurs in the cytosol, no oxygen. Two types: Alcoholic Fermentation and Lactic Acid Fermentation
130
Alcohol Fermentation
Pyruvate is converted into ethanol. (Example: bacteria, yeast)
131
Lactic Acid Fermentation
Pyruvate is reduced directly by NADH to form lactate. (Example: muscle cells. When muscle cells run out of oxygen, they can go through lactic acid fermentation to produce ATP. This causes the burning sensation you may feel when performing strenuous exercise).
132
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 lower the pH. If lactate builds up and is unable to be broken down it can lead to lactic acidosis. Excessively low blood pH.