Download Chapter 8 Cellular Energy

Chapter 8 Cellular
Energy
8.1 Cells and the Flow of Energy
8.2 Metabolic Reactions and Energy
Transformations
8.3 Metabolic Pathways and Enzymes
8.1 How Organisms obtain energy
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Objectives
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Summarize two _________ of thermodynamics.
Compare and contrast __________________ and
heterotrophs.
Describe how ATP works in a _______________.
Transformation of Energy
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Energy: The ability to do _______________
Thermodynamics: study of the flow &
transformation of ____________________ in the
universe.
Laws of Thermodynamics
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Energy cannot be __________________ or
destroyed, but it can be changed from one form to
another.
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Potential  Kinetic
Law of conservation of ____________________
Energy cannot be changed from one form to
another without a _____________ of usable
energy.
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Often times, it is lost in the form of _____________.
(thermal)
Autotrophs & Heterotrophs
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All organisms need energy
Nearly all energy for life comes from the __________
Autotrophs make their own _______________.
Chemoautotrophs use inorganic substances for an energy
source
________________autotrophs use the sun
Heterotrophs need to ingest food (other organisms) to
obtain __________________
Metabolism
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Metabolism: all the ___________ reactions in a cell
Metabolic pathway: product from one becomes the
__________________ for the next (all enzymatic!)
Catabolic: release energy, break down big molecules
into ________________ ones
Anabolic: use ________________ energy by
catabolic to build bigger molecules from smaller ones
Photosynthesis
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Anabolic
Light energy + carbon dioxide + water  glucose
+ oxygen
Glucose can be __________________ to other
organisms when consumed as food
Cellular Respiration
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Catabolic
Organic molecules are _________________ down to
release energy for use by the cell
Oxygen is used to break them down producing
________________________ and water
ATP: The Unit of Cellular Energy
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Types of energy: mechanical,
thermal, chemical, ____________
Adenosine triphosphate:
__________: is the most
important biological molecule that
provides chemical energy.
Adenine base, a ribose
_______________, and three
phosphate groups
Energy is stored in that phosphate
bond and is released. ATPADP
8.2 Photosynthesis
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Objectives:
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Summarize the two ___________________ of
photosynthesis.
Explain the function of a ___________________
during the light reactions.
Describe and diagram __________________
transport.
Photosynthesis
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Light energy converted to __________________ energy
6CO2 + 6H2O  C6H12O6 + 6O2
Two phases:
Light-_______________________: light e is absorbed
and converted into chemical e in the form of ATP and
NADPH
Light-__________________________ : ATP and
NADPH are used to make glucose
Glucose can be joined to other simple carbs, such as
starch.
Can also be made into proteins, lipids, and nucleic acids
Phase One: Light Reactions
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Absorb light and make NADPH and ATP
Chloroplasts: capture __________________ in
photosynthetic organisms
Mainly found in the cells of ________________
Thylakoids: flattened saclike membranes that are
arranged in ________________________.
Grana: the stacks
Light dependent _________________ take place
in thylakoids
Stroma: fluid-filled space outside the grana
Light independent reactions take place in stroma
Pigments
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Pigments: light-absorbing colored molecules found in
the thylakoid _____________________ of
chloroplasts
Chlorophylls are the major light-absorbing
_______________________ in plants.
Chlorophyll a, chlorophyll b are the most common
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Absorb most strongly in the violet-blue region and reflect
green
Carotenoids: absorb in the ____________ and green
regions and reflect in the yellow, orange, and red
regions.
Fall colors are the result of chlorophyll molecules
breaking down and allowing the other pigments to
show through.
Electron Transport
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Light energy absorbed by photosystem II is used to split
water. Oxygen is released, protons (H+ ions) stay in the
thylakoid space and an activated electron enters the
electron transport ______________________.
As electrons move through the membrane, _____________
are pumped into the thylakoid space.
At photosystem I, electrons are re-energized and NADPH
is formed.
Chemiosmosis: protons accumulate in the thylakoid space,
creating a ____________________________ gradient.
When protons move across the thylakoid membrane
through ATP synthase, ADP is converted to ATP.
Phase Two: The Calvin Cycle
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NADPH and ATP are not stable enough to store
energy for a ___________________________.
Carbon fixation: carbon ________________
combines with 5-carbon compounds to make 3carbon molecules called 3-phosphoglycerate.
ATP and NADPH give their stored energy to form
glyceraldehyde 3-phosphates.
Two glyceraldehydes leave to make _____________.
Rubisco (enzyme) converts the remaining G3P
molecules back to 5-carbon molecules so that the
cycle can continue.
Alternative Pathways
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C4 plants
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Minimizes water __________________
Use four-carbon rather than three-carbon molecules
Stoma do not open on ___________________. Special
cells take the carbon compounds so carbon dioxide can
enter and photosynthesis can occur.
CAM plants
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Occurs in plants that live in the _________________
(minimize water loss), salt marshes, and where water is
minimal
Only open stoma at ______________.
During the day, carbon dioxide is released from these
compounds and enters the Calvin cycle.
8.3 Cellular Respiration
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Objectives:
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Summarize the stages of ___________________
respiration.
Identify the role of ____________________
carriers in each stage of cellular respiration.
Compare alcoholic fermentation and lactic
_______________ fermentation.
Cellular Respiration
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Two main parts: Glycolysis and aerobic
respiration
Anaerobic processes: no ______________
required
Aerobic respiration: includes Krebs __________
and electron transport.
Aerobic processes require oxygen
Equation is the _____________ of photosynthesis
Glycolysis
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Glucose is broken down in ________________
via glycolysis
First, two ATP are used to break _____________
into two G3P.
Then, each of these 3-carbon compounds give
phosphates and H+ ions to produce 2 ATP and
one NADH.
Result: 2 NADH and 4 ATP – 2 ATP = 2 ATP
and two pyruvates for Krebs cycle
Krebs Cycle
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Pyruvate converted to acetyl-CoA before cycle
begins, ______________________released.
Pyruvates are transported to mitochondrial matrix
in the presence of ___________________.
Acetyl-CoA combines with 4-carbon compound
to make citric ___________________.
Citric acid broken down, releasing _________
carbon dioxides, one ATP, three NADH, and one
FADH2.
Results in a four-carbon sugar that can combine
with acetyl-CoA to turn it again.
Electron Transport
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This is when NADH and FADH2 from the Krebs cycle
convert ADP to ___________________.
Electrons move along the mitochondrial membrane through
________________________.
The NADH and FADH2 are converted to NAD+ and FAD,
the H+ ___________________ released into m. matrix.
As H+ ions come back through ATP synthase, ADP is
converted to ATP.
One molecule of glucose yields 36 ATP via cellular
respiration.
Anaerobic Respiration
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Aka fermentation.
Fermentation: occurs in the __________________
and regenerates the cell’s supply of NAD+ while
making some _________________.
Lactic acid fermentation and alcohol fermentation are
the two types
Lactic acid: skeletal _________________ produces
lactic acid during strenuous exercise when not getting
oxygen; results in cramping…eat bananas!
Alcohol: Yeast and some bacteria. Results in ethyl
alcohol and carbon dioxide.
Sister Processes
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The products from one reaction are the
____________________ for the
other…photosynthesis and cellular respiration.