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BIOENERGETICBIOENERGETICSS

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What is Bioenergetics?

The study of energyenergy in living systemsliving systems (environments) and the organismsorganisms (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 EnergyEnergy of of

positionposition Includes Includes

energy energy stored in stored in chemical chemical bondsbonds

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Two Types of Energy Reactions

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Endergonic Reactions

Chemical reactionChemical reaction that requires a net input of energyenergy.

PhotosynthesisPhotosynthesis

6CO2 +6H2O C6H12O6 + 6O2

SUNphotonsphotons

LightEnergy

(glucose)(glucose)

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Exergonic Reactions Chemical reactionsChemical reactions that

releases energyreleases energy Cellular Respiration

C6H12O6 + 6O2 6CO2 + 6H2O+ATP(glucose)(glucose)

EnergyEnergy

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Metabolic Reactions of

Cells

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What is Metabolism?

The sum sum totaltotal of the chemical chemical activitiesactivities of all cellscells.

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Two Types of Metabolism

Anabolic Anabolic PathwayPathwayss

CataboliCatabolic c PathwayPathwayss

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Anabolic PathwayAnabolic Pathway Metabolic reactions,Metabolic reactions, which

consume energyconsume energy (endergonic),(endergonic), to buildbuild complicated molecules from simpler compounds.

PhotosynthesisPhotosynthesis

6CO2 + 6H2O C6H12O6 + 6O2

SUNlightlightenergyenergy

(glucose)(glucose)

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Catabolic PathwayCatabolic Pathway Metabolic reactionsMetabolic reactions which

release energyrelease energy (exergonic)(exergonic) by breaking downbreaking down complex molecules in simpler compounds

Cellular RespirationCellular Respiration C6H12O6 + 6O2 6CO2 + 6H2O +

ATP(glucose)(glucose)

energy

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Cellular Energy - Cellular Energy - ATPATP

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ATPATP Components:Components:

1. adenine: nitrogenous 1. adenine: nitrogenous basebase

2. ribose:2. ribose: five carbon five carbon sugarsugar

3.phosphate group: chain 3.phosphate group: chain of 3of 3

riboseribose

adenineadenine

P P P

phosphate groupphosphate group

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Adenosine Adenosine TriphosphateTriphosphate

Three Three phosphate phosphate groups-groups-(two(two with high with high energy bondsenergy bonds

Last Last phosphatephosphate group (POgroup (PO44) ) contains the contains the MOST energyMOST energy

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Breaking the Bonds of Breaking the Bonds of ATPATP

Process is called phosphorylationphosphorylation

Occurs continually in cells

Enzyme ATP-aseATP-ase can weaken & break last POlast PO44 bondbond releasing energy & free PO4

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How does ATP How does ATP work ?work ? Organisms use enzymesenzymes

to break down energy-rich energy-rich glucoseglucose to release its potential energy

This energy is trapped and stored in the form of adenosine adenosine triphosphate(ATP)triphosphate(ATP)

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How Much ATP Do Cells How Much ATP Do Cells Use?Use?

It is estimated that each celleach cell will generate and consume approximately 10,000,000 10,000,000 molecules of molecules of ATP ATP per per secondsecond

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Coupled Reaction - Coupled Reaction - ATPATP The exergonic exergonic

hydrolysishydrolysis of ATPATP is coupled with the endergonic endergonic dehydration dehydration processprocess by transferringtransferring a phosphate groupphosphate group to another molecule.

HH22OO

HH22OO

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Hydrolysis ofHydrolysis of ATP ATPATP + H2O ADP + P (exergonic)

HydrolysisHydrolysis(add water)(add water)

P P P

Adenosine triphosphate (ATP)Adenosine triphosphate (ATP)

P P P++

Adenosine diphosphate (ADP)Adenosine diphosphate (ADP)

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Hyrolysis is ExergonicHyrolysis is Exergonic

EnergEnergy y

Used Used by by

CellsCells

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Dehydration ofDehydration of ATP ATPADP + ADP + P P ATPATP + + HH22O O (endergonic(endergonic)

P P P

Adenosine triphosphate (ATP)Adenosine triphosphate (ATP)

P P P++

Adenosine diphosphate (ADP)Adenosine diphosphate (ADP)

DehydrationDehydration(Remove (Remove HH22OO

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Dehydration is Dehydration is EndergonicEndergonic

Energy Energy is is restorerestored in d in ChemicChemical al BondsBonds

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ReviewReview

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How many high energy How many high energy phosphate bonds does phosphate bonds does

ATP have?ATP have?

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Which is true of Which is true of photosyntheis?photosyntheis?

Anabolic Anabolic or or CatabolicCatabolic

ExergonicExergonic OrOrEndergonicEndergonic

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The breakdown of ATP is The breakdown of ATP is due to:due to:

DehydrationDehydration ororHydrolysisHydrolysis

HH22O addedO added oror HH22O removedO removed

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Which Reactions are Which Reactions are often Coupled in often Coupled in

OrganismsOrganisms

HydrolysisHydrolysis or or DehydrationDehydration

AnabolismAnabolism or or CatabolismCatabolism

EndergonicEndergonic oror ExergonicExergonic

BOTHBOTH

BOTHBOTH

BOTHBOTH

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Ready for the Ready for the test? If not, test? If not,

review and try review and try again!!!again!!!