Term
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Definition
| - is a partial degradation of sugars that occurs without O2 |
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Term
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Definition
•-includes both aerobic and anaerobic respiration but is often used to refer to aerobic respiration
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Term
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Definition
•- consumes organic molecules and O2 and yields ATP |
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Term
•formula for sugar glucose:
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Definition
C6H12O6 + 6 O2 ® 6 CO2 + 6 H2O + Energy (ATP + heat)
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Term
The transfer of electrons during chemical reactions |
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Definition
•releases energy stored in organic molecules which
•is ultimately used to synthesize ATP
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Term
•redox reactions (
oxidation-reduction reactions)
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Definition
Chemical reactions that transfer electrons between reactants |
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Term
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Definition
•a substance loses electrons, or is oxidized
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Term
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Definition
•substance gains electrons, or is reduced (the amount of positive charge is reduced)
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Term
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Definition
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Term
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Definition
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Term
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Definition
•glucose and other organic molecules are broken down in a series of steps
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Term
Electrons from organic compounds are usually |
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Definition
first transferred to NAD+, a coenzyme |
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Term
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Definition
As an electron acceptor
functions as an oxidizing agent during cellular respiration
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Term
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Definition
the reduced form of NAD+
represents stored energy that is tapped to synthesize ATP
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Term
NADH passes the electrons to the |
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Definition
•electron transport chain
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Term
the electron transport chain |
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Definition
•
O2 pulls electrons down the chain in an energy-yielding tumble
•The energy yielded is used to regenerate ATP
passes electrons in a series of steps instead of one explosive reaction |
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Term
•Cellular respiration has three stages:
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Definition
Glycolysis
The citric acid cycle
Oxidative phosphorylation
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Term
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Definition
breaks down glucose into two molecules of pyruvate |
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Term
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Definition
completes the breakdown of glucose |
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Term
Oxidative phosphorylation |
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Definition
accounts for most of the ATP synthesis; 90%
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Term
A smaller amount of ATP is formed in glycolysis and the citric acid cycle by |
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Definition
•substrate-level phosphorylation
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Term
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Definition
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Term
Glycolysis has 2 major phases: |
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Definition
–
Energy investment phase |
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Term
In the presence of O2, pyruvate enters the |
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Definition
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Term
Before the citric acid cycle can begin |
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Definition
pyruvate must be converted to acetyl CoA |
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Term
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Definition
•links the cycle to glycolysis
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Term
The citric acid cycle
(the Kerbs Cycle)
takes place within the
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Definition
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Term
The citric acid cycle
(the Kerbs Cycle)
oxidizes
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Definition
•organic fuel derived from pyruvate, generating 1 ATP, 3 NADH, and 1 FADH2 per turn
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Term
The citric acid cycle has ____ steps .... |
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Definition
8
•each catalyzed by a specific enzyme
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Term
The acetyl group of acetyl CoA |
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Definition
joins the cycle by combining with oxaloacetate, forming citrate |
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Term
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Definition
•decompose the citrate back to oxaloacetate, making the process a cycle
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Term
The NADH and FADH2 produced by the cycle |
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Definition
•relay electrons extracted from food to the electron transport chain
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Term
Following glycolysis and the citric acid cycle, NADH and FADH2 |
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Definition
•account for most of the energy extracted from food
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Term
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Definition
•electron carriers donate electrons to the electron transport chain, which powers ATP synthesis via oxidative phosphorylation
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Term
The electron transport chain is in the |
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Definition
•cristae of the mitochondrion
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Term
The Pathway of Electron Transport |
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Definition
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Term
Most of the chain’s components are |
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Definition
| proteins, which exist in multiprotein complexes |
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Term
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Definition
alternate reduced and oxidized states as they accept and donate electrons |
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Term
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Definition
•free energy as they go down the chain and are finally passed to O2, forming H2O
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Term
Electrons are transferred from |
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Definition
•NADH or FADH2 to the electron transport chain
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Term
Electrons are passed through a number of |
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Definition
•proteins including cytochromes (each with an iron atom) to O2
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Term
The electron transport chain generates |
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Definition
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Term
electron transport chain
function is to
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Definition
break the large free-energy drop from food to O2 into smaller steps that release energy in manageable amounts |
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Term
Chemiosmosis: The Energy-Coupling Mechanism |
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Definition
| this serves as a divider so u (i) dont get comfused |
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Term
| Electron transfer in the electron transport chain causes |
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Definition
proteins to pump H+ from the mitochondrial matrix to the intermembrane space |
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Term
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Definition
back across the membrane, passing through channels in ATP synthase |
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Term
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Definition
•
exergonic flow of H+ to drive phosphorylation of ATP |
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Term
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Definition
the use of energy in a H+ gradient to drive cellular work |
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Term
The energy stored in a H+ gradient across a membrane |
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Definition
•couples the redox reactions of the electron transport chain to ATP synthesis
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Term
The H+ gradient is referred to as a |
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Definition
•proton-motive force, emphasizing its capacity to do work
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Term
An Accounting of ATP Production by Cellular Respiration |
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Definition
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Term
•During cellular respiration, most energy flows in this sequence:
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Definition
glucose ® NADH ® electron transport chain ® proton-motive force ® ATP
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Term
About 40% of the energy in a glucose molecule is |
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Definition
•transferred to ATP during cellular respiration, making about 38 ATP
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Term
Fermentation and anaerobic respiration enable |
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Definition
cells
to produce ATP without the use of oxygen |
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Term
Most cellular respiration requires ___
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Definition
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Term
Glycolysis can produce ATP with or without |
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Definition
•
(in aerobic or anaerobic conditions)
O2 |
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Term
In the absence of O2, glycolysis |
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Definition
•
couples with fermentation or anaerobic respiration to produce ATP |
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Term
Anaerobic respiration uses .... and ex: |
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Definition
•an electron transport chain with an electron acceptor other than O2, for example sulfate
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Term
Fermentation uses _______ instead of |
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Definition
phosphorylation
an electron transport chain to generate ATP
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Term
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Definition
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Term
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Definition
•glycolysis + reactions that regenerate NAD+, which can be reused by glycolysis
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Term
Two common types of fermentation are: |
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Definition
•alcohol fermentation & lactic acid fermentation
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Term
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Definition
•pyruvate is converted to ethanol in two steps, with the first releasing CO2
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Term
Ex of
alcohol fermentation |
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Definition
yeast is used in brewing, winemaking, and baking |
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Term
In lactic acid fermentation |
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Definition
•pyruvate is reduced to NADH, forming lactate as an end product, with no release of CO2
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Term
2 exs of
Lactic acid fermentation |
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Definition
by some fungi and bacteria is used to make cheese and yogurt
•Human muscle cells use lactic acid fermentation to generate ATP when O2 is scarce
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Term
Fermentation and Aerobic Respiration Compared |
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Definition
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Term
Both
Fermentation and Aerobic Respiration use |
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Definition
glycolysis to oxidize glucose and other organic fuels to pyruvate |
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Term
Fermentation and Aerobic Respiration
have different final electron acceptors
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Definition
•an organic molecule (such as pyruvate or acetaldehyde) in fermentation and O2 in cellular respiration
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Term
Cellular respiration produces ___ ATP per glucose molecule |
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Definition
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Term
fermentation produces __ATP per glucose molecule |
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Definition
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Term
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Definition
•carry out fermentation or anaerobic respiration and cannot survive in the presence of O2
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Term
facultative anaerobes and exs: |
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Definition
Yeast and many bacteria
meaning that they can survive using either fermentation or cellular respiration
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Term
In a facultative anaerobe, pyruvate |
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Definition
•is a fork in the metabolic road that leads to two alternative catabolic routes
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Term
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Definition
•
Directly / indirectly
•nourishes almost the entire living world
is the process that converts solar energy into chemical energy |
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Term
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Definition
are the producers of the biosphere |
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Term
Autotrophs sustain themselves |
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Definition
without eating anything derived from other organisms |
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Term
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Definition
•organic molecules from CO2 and other inorganic molecules
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Term
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Definition
•photoautotrophs, using the energy of sunlight to make organic molecules from H2O and CO2
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Term
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Definition
•
•These organisms feed not only themselves but also most of the living world
plants, algae, certain other protists, and some prokaryotes |
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Term
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Definition
•
they obtain their organic material from other organisms
are the consumers of the biosphere |
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Term
all heterotrophs, including humans, depend on |
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Definition
photoautotrophs for food and O2 |
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Term
Chloroplasts: The Sites of Photosynthesis in Plants |
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Definition
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Term
•the major locations of photosynthesis are
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Definition
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Term
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Definition
•the green pigment within chloroplasts
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Term
| Light energy absorbed by chlorophyll drives |
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Definition
| the synthesis of organic molecules in the chloroplast |
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Term
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Definition
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Term
__ enters and __ exits the leaf |
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Definition
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Term
Chloroplasts are found mainly in cells of the |
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Definition
|
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Term
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Definition
is
the interior tissue of the leaf |
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Term
A typical mesophyll cell has _______
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Definition
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Term
The chlorophyll is in the membranes of |
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Definition
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Term
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Definition
connected sacs in the chloroplast |
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Term
•
thylakoids may be stacked in columns called
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Definition
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Term
Chloroplasts also contain |
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Definition
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Term
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Definition
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Term
Tracking Atoms Through Photosynthesis: Scientific Inquiry Tracking Atoms Through Photosynthesis: Scientific Inquiry
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Definition
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Term
•Photosynthesis can be summarized as the following equation:
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Definition
6 CO2 + 12 H2O + Light energy ® C6H12O6 + 6 O2 + 6 H2O
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Term
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Definition
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Term
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Definition
H2O into hydrogen and oxygen, incorporating the electrons of hydrogen into sugar molecules |
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Term
Photosynthesis as a Redox Process |
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Definition
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Term
Photosynthesis is a ____ process in which |
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Definition
| H2O is oxidized and CO2 is reduced |
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Term
The Two Stages of Photosynthesis |
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Definition
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Term
Photosynthesis consists of the |
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Definition
•light reactions (the photo part) and Calvin cycle (the synthesis part)
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Term
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Definition
–
in the thylakoids
Split H2O
–Release O2
–Reduce NADP+ to NADPH
–Generate ATP from ADP by photophosphorylation
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Term
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Definition
•
forms sugar from CO2, using ATP and NADPH
in the stroma |
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Term
The Calvin cycle begins with |
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Definition
carbon fixation, incorporating CO2 into organic molecules |
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Term
The light reactions convert solar energy to the chemical energy of ATP and NADPH |
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Definition
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Term
the
Chloroplasts's
thylakoids
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Definition
•transform light energy into the chemical energy of ATP and NADPH
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Term
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Definition
|
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Term
|
Definition
is a form of electromagnetic energy, also called electromagnetic radiation
• travels in rhythmic waves
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Term
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Definition
•is the distance between crests of waves
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Term
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Definition
•the type of electromagnetic energy
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Term
The electromagnetic spectrum |
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Definition
is the entire range of electromagnetic energy, or radiation |
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Term
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Definition
•consists of wavelengths (including those that drive photosynthesis) that produce colors we can see
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Term
Light also behaves as though it consists of discrete particles, called |
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Definition
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Term
Photosynthetic Pigments: The Light Receptors |
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Definition
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Term
Pigments are substances that |
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Definition
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Term
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Definition
•absorb different wavelengths
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Term
Wavelengths that are not absorbed |
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Definition
•are reflected or transmitted
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Term
Leaves appear green because |
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Definition
•chlorophyll reflects and transmits green light
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Term
Excitation of Chlorophyll by Light |
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Definition
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Term
When a pigment absorbs light |
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Definition
•it goes from a ground state to an excited state, which is unstable
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Term
When excited electrons fall back to the ground state |
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Definition
•photons are given off, an afterglow called fluorescence
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Term
If illuminated, an isolated solution of chlorophyll |
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Definition
will fluoresce, giving off light and heat |
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Term
A photosystem consists of a |
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Definition
reaction-center complex
surrounded by light-harvesting complexes
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Term
a reaction-center complex is: |
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Definition
| a type of protein complex |
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Term
light-harvesting complexes are... and... |
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Definition
pigment molecules bound to proteins
•funnel the energy of photons to the reaction center
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Term
A primary electron acceptor in the reaction center |
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Definition
•accepts an excited electron from chlorophyll a
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Term
the first step of the light reactions |
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Definition
Solar-powered transfer of an electron from a chlorophyll a molecule to the primary electron acceptor |
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Term
•There are two types of photosystems in the thylakoid membrane
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Definition
|
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Term
|
Definition
functions first
•and is best at absorbing a wavelength of 680 nm
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Term
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Definition
•is best at absorbing a wavelength of 700 nm
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Term
The reaction-center chlorophyll a of PS II is called |
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Definition
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Term
The reaction-center chlorophyll a of PS I is called |
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Definition
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Term
|
Definition
|
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Term
During the light reactions, there are two possible routes for electron flow |
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Definition
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Term
Linear electron flow is the: |
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Definition
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Term
Linear electron flow involves: |
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Definition
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Term
Linear electron flow produces: |
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Definition
| ATP and NADPH using light energy |
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Term
Linear electron flow goes as follows? |
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Definition
• A photon hits a pigment and its energy is passed among pigment molecules until it excites P680
• An excited electron from P680 is transferred to the primary electron acceptor
• P680+ (P680 that is missing an electron) is a very strong oxidizing agent
• H2O is split by enzymes, and the electrons are transferred from the hydrogen atoms to P680+, thus reducing it to P680
• O2 is released as a by-product of this reaction
• Each electron “falls” down an electron transport chain from the primary electron acceptor of PS II to PS I
• Energy released by the fall drives the creation of a proton gradient across the thylakoid membrane
• Diffusion of H+ (protons) across the membrane drives ATP synthesis
• In PS I (like PS II), transferred light energy excites P700, which loses an electron to an electron acceptor
• P700+ (P700 that is missing an electron) accepts an electron passed down from PS II via the electron transport chain
• Each electron “falls” down an electron transport chain from the primary electron acceptor of PS I to the protein ferredoxin (Fd)
• The electrons are then transferred to NADP+ and reduce it to NADPH
• The electrons of NADPH are available for the reactions of the Calvin cycle |
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Term
|
Definition
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Term
Cyclic electron flow uses |
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Definition
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Term
Cyclic electron flow
produces |
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Definition
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Term
Cyclic electron flow generates |
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Definition
•surplus ATP, satisfying the higher demand in the Calvin cycle
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Term
|
Definition
•protect cells from light-induced damage
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Term
A Comparison of Chemiosmosis in Chloroplasts and Mitochondria |
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Definition
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Term
both Chloroplasts and mitochondria generate |
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Definition
•ATP by chemiosmosis, BUT use different sources of energy
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Term
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Definition
chemical energy from food to ATP |
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Term
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Definition
light energy into the chemical energy of ATP |
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Term
In mitochondria, protons are |
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Definition
•pumped to the intermembrane space and drive ATP synthesis as they diffuse back into the mitochondrial matrix
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Term
In chloroplasts, protons are |
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Definition
pumped into the thylakoid space and drive ATP synthesis as they diffuse back into the stroma |
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Term
|
Definition
•ATP and increase the potential energy of electrons by moving them from H2O to NADPH
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Term
The Calvin cycle uses ATP and NADPH to convert CO2 to sugar |
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Definition
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Term
The Calvin cycle, like the citric acid cycle |
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Definition
•regenerates its starting material after molecules enter and leave the cycle
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Term
The Calvin cycle
builds sugar from .... and ...
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Definition
•smaller molecules by using ATP.... the reducing power of electrons carried by NADPH
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Term
Alternative mechanisms of carbon fixation have evolved in hot, arid climates |
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Definition
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Term
|
Definition
•On hot, dry days, plants close stomata, which conserves H2O but also limits photosynthesis
•The closing of stomata reduces access to CO2 and causes O2 to build up
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Term
Photorespiration: An Evolutionary Relic? |
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Definition
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Term
In most plants (C3 plants), initial fixation of CO2, via rubisco |
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Definition
•forms a three-carbon compound
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Term
|
Definition
•rubisco adds O2 instead of CO2 in the Calvin cycle
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Term
Photorespiration consumes |
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Definition
•O2 and organic fuel and releases CO2 without producing ATP or sugar
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Term
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Definition
•damaging products of light reactions that build up in the absence of the Calvin cycle
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Term
photorespiration is a problem because on a hot, dry day it can |
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Definition
drain as much as 50% of the carbon fixed by the Calvin cycle |
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Term
|
Definition
|
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Term
|
Definition
•
This step requires the enzyme PEP carboxylase
the cost of photorespiration by incorporating CO2 into four-carbon compounds in mesophyll cells |
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Term
PEP carboxylase has ....it... |
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Definition
a higher affinity for CO2 than rubisco does.....
it can fix CO2 even when CO2 concentrations are low
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Term
These four-carbon compounds are exported to |
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Definition
•bundle-sheath cells, where they release CO2 that is then used in the Calvin cycle
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Term
|
Definition
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Term
Some plants, including succulents, use ____ to fix carbon |
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Definition
crassulacean acid metabolism (CAM) |
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Term
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Definition
open their stomata at night, incorporating CO2 into organic acids |
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Term
Stomata close during the day, and |
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Definition
•CO2 is released from organic acids and used in the Calvin cycle
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|
