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Cellular RespirationCellular Respiration

Harvesting Chemical Energy from Harvesting Chemical Energy from Organic Molecules Organic Molecules

Releasing Energy From GlucoseReleasing Energy From GlucoseGlucose (6C)Glucose (6C)

2 X Pyruvate (3C)2 X Pyruvate (3C)

2 X Acetyl-CoA (2C)2 X Acetyl-CoA (2C)

CytoplasmCytoplasm

MitochondrionMitochondrion

Krebs Krebs CycleCycle

ATPATPee-- Carriers Carriers

ee-- Carriers Carriers

ee-- Carriers Carriers

Electron Transport Chain

Electron Transport Chain

½ O½ O22

HH22OO

ATPATP

2 H2 H++

COCO22

COCO22

ATPATP

GlycolysisGlycolysis

EnergyReleased

ee--

ee--ee--

EnergyReleased

Structure of a Structure of a Mitochondrion Mitochondrion

Matrix: Krebs CycleMatrix: Krebs Cycle

A CellA Cell

One of ItsOne of ItsMitochondriaMitochondria

A CristaA Crista

InnerInnerMembrane:Membrane:Has Electron Has Electron Transport ChainTransport Chain

IntermembraneIntermembraneCompartmentCompartment

aabb

cc

OuterOuterMembraneMembrane

Glucose Breakdown Glucose Breakdown Yields EnergyYields Energy

• CC66HH1212OO66 + 6O + 6O22 6CO 6CO22 + 6H + 6H22O + energyO + energy

– 40% of released energy captured in ATP 40% of released energy captured in ATP

• Involves two electron carriersInvolves two electron carriers– NADNAD++ + H + H++ + 2 electrons + 2 electrons NADH NADH

– FAD + 2HFAD + 2H++ + 2 electrons + 2 electrons FADH FADH22

– Electrons donated to Electron Transport Electrons donated to Electron Transport Chain to produce ATPChain to produce ATP


4 ATP4 ATP

2 NADH2 NADH

2 ATP2 ATP

2 NAD2 NAD++

Set

of 1

0 r e

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et o

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r eac

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2 X Pyruvate (3C)2 X Pyruvate (3C) CC CC CC CC CC CC

Glucose (6C)Glucose (6C) CC CC CC CC CC CC

Net gain of 2 ATPNet gain of 2 ATP

Occurs in cytoplasm under anaerobic conditionsOccurs in cytoplasm under anaerobic conditionsReverse pathway can convert pyruvate Reverse pathway can convert pyruvate glucoseglucose

Formation of Acetyl CoAFormation of Acetyl CoA

CC CC CC CC CC CC

CoACoACoACoA

CC CC CC CC CC CCPyruvatesPyruvates

CoACoACoACoA

CC CC CC CC

NADNAD++NADNAD++

NADHNADHNADHNADH

CCOO

OOCC

OO

OO

Acetyl CoAAcetyl CoA

CC CC CC CC

Occurs in mitochondrion; Not reversible Occurs in mitochondrion; Not reversible

Krebs Cycle Krebs Cycle

CC CC CC CCCC

NADHNADH

CC CC CC CC

CoACoA

CCCC CC CC CCCC

CCO

O

CCO

O

NADNAD++

NADHNADH

NADNAD++

NADHNADH

ADPADP

ATPATP

HH22OO

NADNAD++

FADHFADH22

FADFAD

HH22OO

CC CC CC CC

CCCC CC CC CCCC

CoACoA

NADNAD++

NADHNADH

CCO

O

CC CC CC CCCC

HH22OO

NADNAD++

NADHNADH

ADPADP

ATPATP

CCO

O

CC CC CCCC

NADHNADH

NADNAD++

FADHFADH22

FADFAD

HH22OO

1

2 3

4

5 6 7

CCCC CC CC CCCCCC CC CC CCCC

CC CC CCCC

CoACoACoACoA CC CC CC CCAcetyl CoAAcetyl CoA

Krebs Cycle: SummaryKrebs Cycle: SummaryCoACoA CC CC

Acetyl-CoA (2C)Acetyl-CoA (2C)

2 X2 X

Krebs CycleKrebs CycleSet of 7 reactionsSet of 7 reactions 6 NAD6 NAD++ 6 NADH6 NADH

2 FAD2 FAD 2 FADH2 FADH22

2 ADP2 ADP 2 ATP2 ATP

Electron Transport ChainElectron Transport Chain

4 CO4 CO22 CC

Energy Harvested from GlucoseEnergy Harvested from Glucose

(Cytoplasm)(Cytoplasm) GlucoseGlucose

2 NADH2 NADH2 NADH2 NADH6 NADH6 NADH2 FADH2 FADH22

2 Pyruvates2 Pyruvates

2 CO2 CO22

4 CO4 CO22

2 ATP2 ATP 4 ATP4 ATP

(Mitochondrial(MitochondrialMatrix)Matrix)

(Inner(InnerMembrane)Membrane)

2 ATP2 ATP

32 ATP32 ATPElectron TransportElectron Transport

SystemSystem


KrebsKrebsCycleCycle

WaterWater

OxygenOxygen

2 ATP2 ATPNet Gain

Applying Your KnowledgeApplying Your Knowledge

A.A. Where is the Krebs cycle located?Where is the Krebs cycle located?B.B. Where does glycolysis occur?Where does glycolysis occur?

C.C. Where is COWhere is CO2 2 produced? produced?

D.D. Where is the electron transport chain Where is the electron transport chain located?located?

1.1. CytoplasmCytoplasm

2.2. Mitochondrial MatrixMitochondrial Matrix

3.3. Inner Membrane of MitochondrionInner Membrane of Mitochondrion

4.4. Choices 1 and 2 are correct.Choices 1 and 2 are correct.

5.5. All of these are correct. All of these are correct.

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ATP is Produced by ATP is Produced by ChemiosmosisChemiosmosis

• Diffusion of hydrogen ions (HDiffusion of hydrogen ions (H++ ) through ) through a differentially permeable membrane, a differentially permeable membrane, resulting in ATP productionresulting in ATP production– energy from electron transport pumps Henergy from electron transport pumps H++

to intermembrane compartment of to intermembrane compartment of mitochondrionmitochondrion

– HH++ diffuses to matrix through pores of ATP- diffuses to matrix through pores of ATP-synthesizing enzymesynthesizing enzyme

– movement of Hmovement of H++ provides energy for ATP provides energy for ATP synthesissynthesis

MitochondrialMitochondrialChemiosmosis Chemiosmosis

Mitochondrial Chemiosmosis Mitochondrial Chemiosmosis

Mitochondrial ChemiosmosisMitochondrial Chemiosmosis

Mitochondrial Electron Transport SystemMitochondrial Electron Transport System

Without Oxygen, Fermentation Occurs Without Oxygen, Fermentation Occurs

Traffic backed up into mitochondrion

Alcoholic Fermentation for YeastAlcoholic Fermentation for Yeast

NADNAD++

CC CC CC CC CC CC

GlucoseGlucose

CC CC CC

GlycolysisGlycolysis AlcoholicAlcoholicFermentationFermentation

NADNAD++ NADHNADH

ADPADP ATPATP

ADPADP ATPATP

PyruvatesPyruvates EthanolsEthanolsCC CC CC CC CC

CC CC

NADNAD++NADNAD++ NADHNADH

CCO

O CCO

O

NADHNADHNADHNADH

Lactate Fermentation in MusclesLactate Fermentation in Muscles

NADNAD++

CC CC CC CC CC CC

GlucoseGlucose

CC CC CC

CC CC CCGlycolysisGlycolysis LactateLactate

FermentationFermentation

NADNAD++ NADHNADH

ADPADP ATPATP

ADPADP ATPATP

PyruvatesPyruvates LactatesLactatesCC CC CC

CC CC CC

NADNAD++NADNAD++ NADHNADH

NADHNADHNADHNADH


A.A. Muscle cells produce lactate Muscle cells produce lactate

B.B. Muscle cells produce ATPMuscle cells produce ATP

C.C. Yeast cells produce alcoholYeast cells produce alcohol

1.1. In the Presence of OxygenIn the Presence of Oxygen

2.2. In the Absence of OxygenIn the Absence of Oxygen

3.3. Either in the presence or absence of Either in the presence or absence of OxygenOxygen

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Energy From MacromoleculesEnergy From Macromolecules

Glucose (6C)Glucose (6C)





MonosaccharidesMonosaccharides

Complex CarbohydratesComplex Carbohydrates

DisaccharidesDisaccharides







TriglyceridesTriglycerides

Fatty Acids Fatty Acids multiples of 2C multiples of 2C

GlycerolGlycerol(~5%) (~5%)







ProteinsProteins

Other amino Other amino AcidsAcids

3C-amino 3C-amino acidsacids


A.A. Muscle cells use fats for Muscle cells use fats for energy energy

B.B. Muscle cells use glucose or Muscle cells use glucose or glycogen for energyglycogen for energy

1.1. In the Presence of OxygenIn the Presence of Oxygen

2.2. In the Absence of OxygenIn the Absence of Oxygen

3.3. Either in the presence or absence of Either in the presence or absence of OxygenOxygen

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A.A. Brain cells use glucose for Brain cells use glucose for energyenergy

B.B. Brain cells use proteins for Brain cells use proteins for energy energy

1.1. In the Presence of CarbohydratesIn the Presence of Carbohydrates

2.2. In the Absence of CarbohydratesIn the Absence of Carbohydrates

3.3. Either in the presence or absence of Either in the presence or absence of CarbohydratesCarbohydrates

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