AP BIOLOGY

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Dr. Michael C. Potter Paul VI Catholic High
School Fairfax, Virginia
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ENERGY Ability to do work States of
Energy Potential Kinetic Forms of Energy
Mechanical Heat Atomic, etc.
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Potential Energy Kinetic Energy
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MEASUREMENT OF ENERGY Calorie Amount of heat
needed to raise 1.0 Gm. H2O 1.0 Co Kcal
(kilocalorie) Joule SI unit of work
(energy) Energy needed to raise 1.0 Kg. 1.0
meter 1.0 Kcal. 4.184 kilojoules
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ALL Energy obtained from Sun 13X1023 calories
per yearor 40 million billion
calories/sec. Sun energy stored as
potential energy in chemical cmpds.
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Oxidation Reduction Reactions
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OXIDATION/REDUCTION REACTION OXIDATION
Molecule LOSES electron REDUCTION Molecule
GAINS electron REDOX REACTIONS i.e.
coupled reactions
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OXIDIZING AGENT Causes oxidation in
molecule therefore is reduced REDUCING
AGENT Causes reduction in molecule therefore
is oxidized LEO the lion says GER!
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FIRST LAW OF THERMODYNAMICS Energy can
neither be made nor destroyed only changed
from one form to another The TOTAL AMOUNT
of energy in the universe remains constant
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SECOND LAW OF THERMODYNAMICS ENTROPY is
increasing, i.e. disorder is more likely
than order Entropy is the measure of
disorder in a system
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Second Law of Thermodynamics
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FREE ENERGY That energy in a system that is
available to do work Free Energy equals
ENTHALPY minus ENTROPY times Ko
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Josiah Willard Gibbs Professor of
Mathematics Yale University
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GIBBS FREE ENERGY Josiah Willard Gibbs
?G CHANGE in Free Energy Negative value -
exothermic Positive value endothermic ACTIVATIO
N ENERGY Energy required to initiate a
chemical reaction
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CATALYSTS Lower Activation nrg. ENZYMES Protein
catalysts Mechanisms of Action (4) Factors
Affecting Activity Inhibition
Competitive Inhibition Non-Competitive
Inhibition
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ENZYMES Factors Affecting
Activity Activation Activators
Maintain active configuration
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ENZYME COFACTORS Usually inorganic substances
e.g. ions COENZYMES Nonprotein
organic molecules (vitamins) NADH (reduced
form) FADH2 (reduced form)
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COENZYME NADH
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ADENOSINE TRIPHOSPHATE (ATP) Nucleotide
consisting of Ribose Adenine (N-containing
base) Three PO4 groups Transient Existence
(Use it or lose it)
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Adenine
Ribose
Phosphate groups
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Energy (Potential) stored in bond Yields 7.3
kcal/mol when ATP?ADP Provides energy for
most endergonic reactions Coupled Reactions
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EVOLUTION OF METABOLISM 1. Degradation 2.
Glycolysis 3. Anaerobic Photosynthesis 4.
Nitrogen Fixation 5. O2 Forming
Photosynthesis 6. Aerobic Respiration
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• GLUCOSE CATABOLISM
• STAGE I GLYCOLYSIS
• STAGE II PYRUVATE OXIDATION
• STAGE III KREBS CYCLE
• STAGE IV ELECTRON TRANSPORT

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• GLYCOLYSIS A process that occurs
• in the cytoplasm of every living cell
• 1. Glucose Priming This changes
• glucose into a molecule that can be
• cleaved.
• Requires 2 molecules of ATP
• Phosphofructokinase commits
• glucose to glycolysis

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• GLYCOLYSIS
• 2. Splitting Rearrangement
• Six carbon compound splits
• to (2) 3 carbon cmpds.
• Fructose 1,6, Diphosphate into
• (2) Glyceraldehyde 3 PO4
• Substrate Level Phosphorylation
• Making ATP (4 molecules/glucose)

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GLYCOLYSIS 3. Oxidation Removal of electrons
(energy) capturing in NADH from NAD.
4. ATP Generation 4 reactions that convert
G-3-PO4 to Pyruvate Generates 2 ATP per
Pyruvate
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GLYCOLYSIS RESULTS IN Glucose ? 2 molecules
Pyruvate 2 molecules ADP ? ATP for
each molecule of pyruvate 2 molecules NAD ?
NADH from oxidation of glyceraldehyde-3-PO4
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B. Oxidation of Pyruvate Occurs in
mitochondrion 1. Aerobic conditions Pyruvate
OXIDIZED to Acetyl CoA 2. Anaerobic
conditions result in FERMENTATION REACTIONS
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Metabolism of Pyruvate
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FERMENTATION REACTIONS 1.Lactic Acid
Fermentation Pyruvate REDUCED to Lactate No
CO2 removal NADH ? NAD 2. Alcohol
Fermentation Fungal (Yeast) Cells Pyruvate
REDUCED to Alcohol CO2 Removed NADH ? NAD
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C. KREBS CYCLE 1. Priming
Reactions Prepares the molecule for energy
extraction Acetyl CoA (2C) joins oxaloacetate
(4C) to form Citrate (6C) Citrate isomerizes
to Isocitrate
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C. KREBS CYCLE 2. Energy Extraction-
oxidation reactions disassembling the
molecule Decarboxylation Reactions
Reduction NAD? NADH Reduction FAD ?
FADH2 Regeneration oxaloacetate
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D. ELECTRON TRANSPORT System of REDOX
reactions Series of membrane electron
carriers Ubiquinone (quinone
molecule) Cytochromes (contain Fe) OXYGEN is
final electron acceptor Water is final product
(two H) attach to oxygen
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D. ELECTRON TRANSPORT The movement of electrons
down the concentration gradient to O2 as
the final acceptor releases protons (H) to
the intermembrane space Protons move thru
ATP synthase making ATP from ADP (oxidative
phosphorylation)
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Four major components of electron trans- port
system
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ENERGY (ATP) YIELD per GLUCOSE Glycolysis 2ATP
by substrate level phosphorylation Oxidation
Pyruvate 2 NADH (3 ATP per) Krebs Cycle 6
NADH (3 ATP per) 2 FADH2 (1-2 ATP per) 2
ATP via GTP Electron Transport 32 ATP
oxidative phosphorylation
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Control of Glucose Catabolism Feedback
inhibition Phosphofructokinase inhibited by
ATP levels Citrate levels Phosphofructokinase
stimulated by ADP levels AMP levels
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There is a mutualistic symbiotic relationship
between the products of glycolysis and the
requirements for photosynthesis. This is an
interrelationship between the cells mitochondria
and chloroplast.
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PHOTOSYNTHESIS LIGHT DEPENDENT REACTIONS 1.
Captures energy 2. Makes ATP NADPH LIGHT
INDEPENDENT REACTIONS 3. Use ATP NADPH for
synthesis organic compound
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PHOTOSYNTHESIS A process whereby radiant
electromagnetic energy (light) is transformed
by a specific photo- chemical system located
in the thylakoid to yield chemical energy
in the form of reducing potential (NADPH)
and ATP.
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CHLOROPLAST Double membrane, DNA
containing organelle Internal membrane
formed into Thylakoids (contain
photosystem) Grana (stacks of thylakoids)
Stroma in internal compartment
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PHOTOSYSTEM OVERVIEW Acts as an antenna,
i.e. absorbs light energy Energy passed via
chlorophyll Förster resonance energy
transfer Energy transfer _at_ Reaction Center
Membrane Proteins move energy Forms ATP and
NADPH
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PHOTOSYSTEM OVERVIEW
THE PROCESS OF TRANSDUCTION OF LIGHT ENERGY INTO
CHEMICAL NRG, THE PHOTOCHEMICAL EVENT, IS THE
ESSENCE OF PHOTOSYNTHESIS.
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ELECTROMAGNETIC SPECTRUM Visible Light
Spectrum Range from 400nm-750nm Gamma rays to
Radio Waves Measured in cps (Hertz) ? is symbol
for wavelength
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Absorption Spectrum of Chlorophyll a
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OVERALL Rx OF PHOTOSYNTHESIS
6CO212H2O?C6H12O66O26H2O Reactions of
Photosynthesis are divided into Photo,
i.e. light dependent in thylakoid Synthesis,
i.e. carbon fixation light independent, occurs
in the stroma
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LIGHT DEPENDENT REACTIONS 1. Primary Photo
Event 2. Electron Transport 3.
Chemiosmosis May be Cyclic or Noncyclic LIGHT
INDEPENDENT REACTION 1. Calvin-Benson
Cycle CO2 Fixation Organic Synthesis
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PHOTOSYSTEMS a network of Chlorophyll a and
accessory pigments held within a
protein matrix on the surface of the
photo- synthetic membrane.
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PHOTOSYSTEMS CONSIST OF 1. Antenna Complex
2. Reaction Center PHOTOSYSTEM I Absorption
peak of 700nm. (P700) PHOTOSYSTEM II
Absorption peak of 680nm. (P680)
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NONCYCLIC ELECTRON TRANSPORT Begins with
Photosystem II Pheophytin (1o electron
acceptor) Electron Transport Chain Photolysis
(splitting water) This is the MOST IMPORTANT
chemical reaction on earth.
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LIGHT INDEPENDENT REACTION Utilizes the
materials from the light dependent
reactions, i.e. Energy (ATP from Photo 2)
Reducing Power (NADPH from Photo 1)
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CALVIN CYCLE
3CO2 9ATP 6NADPH water reacts to yield
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CRASSULACEAN ACID PATHWAY Present in warmer
climates Allows stomata to close during day
(Preserve H2O) Characterized by Cactus Pinea
pple Temporal separation of steps
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C4 PATHWAY (Hatch-Slack Pathway) Allows
stomata to close during day Characterized
by Grasses, Sugar Cane, Corn Spatial
Separation of steps
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FACTORS AFFECTING PHOTOSYNTHESIS

• Water Shortage
• Temperature
• Light Intensity

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