BIOENERGETICS
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What is Bioenergetics?
The study of
energy in living
systems
(environments)
and the
organisms
(plants and
animals) that
utilize them
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Energy


Required by
all organisms
May be
Kinetic or
Potential
energy
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Kinetic Energy


Energy of
Motion
Heat and
light energy
are
examples
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Potential Energy


Energy of
position
Includes
energy
stored in
chemical
bonds
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Two Types of
Energy Reactions
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Endergonic Reactions


Chemical reaction that
requires a net input of
energy.
Photosynthesis
SUN
photons
Light
Energy
6CO2 + 6H2O C6H12O6 + 6O2
(glucose)
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Exergonic Reactions


Chemical reactions that
releases energy
Cellular Respiration
Energy
C6H12O6 + 6O2  6CO2 + 6H2O+ ATP
(glucose)
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Metabolic Reactions
of Cells
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What is Metabolism?

The sum total
of the
chemical
activities of
all cells.
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Two Types of Metabolism


Anabolic
Pathways
Catabolic
Pathways
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Anabolic Pathway


Metabolic reactions, which
consume energy (endergonic), to
build complicated molecules from
simpler compounds.
light
SUN
energy
Photosynthesis
6CO2 + 6H2O  C6H12O6 + 6O2
(glucose)
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Catabolic Pathway


Metabolic reactions which release
energy (exergonic) by breaking
down complex molecules in simpler
compounds
energy
Cellular Respiration
C6H12O6 + 6O2  6CO2 + 6H2O + ATP
(glucose)
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Cellular Energy ATP
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ATP

Components:
1. adenine: nitrogenous base
2. ribose: five carbon sugar
3.phosphate group: chain of 3
adenine
phosphate group
P
P
P
ribose
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Adenosine Triphosphate


Three
phosphate
groups-(two
with high
energy bonds
Last phosphate
group (PO4)
contains the
MOST energy
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Breaking the Bonds of ATP



Process is called
phosphorylation
Occurs continually
in cells
Enzyme ATP-ase
can weaken &
break last PO4
bond releasing
energy & free PO4
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How does ATP work ?


Organisms use enzymes to
break down energy-rich
glucose to release its
potential energy
This energy is trapped and
stored in the form of
adenosine triphosphate(ATP)
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How Much ATP Do Cells Use?

It is estimated
that each cell
will generate
and consume
approximately
10,000,000
molecules of
ATP per second
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Coupled Reaction - ATP

The exergonic
hydrolysis of ATP
is coupled with
the endergonic
dehydration
H2O
process by
transferring a
phosphate group
to another
H 2O
molecule.
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Hydrolysis of ATP
ATP + H2O 
ADP + P
(exergonic)
Adenosine triphosphate (ATP)
P
P
P
Hydrolysis
(add water)
P
P
+
P
Adenosine diphosphate (ADP)
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Hyrolysis is Exergonic
Energy
Used
by
Cells
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Dehydration of ATP
ADP + P

(endergonic)
ATP + H2O
Dehydration
(Remove H2O
P
P
+
P
Adenosine diphosphate (ADP)
Adenosine triphosphate (ATP)
P
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P
P
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Dehydration is Endergonic
Energy
is
restored
in
Chemical
Bonds
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Review
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How many high energy
phosphate bonds does ATP
have?
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Which is true of photosyntheis?
Anabolic
or
Catabolic
Exergonic
Or
Endergonic
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The breakdown of ATP is
due to:
Dehydration
or
Hydrolysis
H2O added
or
H2O removed
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Which Reactions are often
Coupled in Organisms
Hydrolysis
Anabolism
Endergonic
or
BOTH
Dehydration
or
Catabolism
or
Exergonic
BOTH
BOTH
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Ready for the test?
If not, review and
try again!!!
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