cellular respiration

Cellular RespirationCellular Respiration

When we eat, we get energy (glucose When we eat, we get energy (glucose and other sugars)and other sugars)

Food energy is broken down into usable Food energy is broken down into usable energyenergy

Energy used to bond phosphate Energy used to bond phosphate groups to ADP to make ATP groups to ADP to make ATP


What is cell respiration???What is cell respiration???

Respiration:Respiration: the process of breaking the process of breaking down food molecules into usable energydown food molecules into usable energy

THE GOAL:THE GOAL: Create ATP for cells to useCreate ATP for cells to use Free up electrons—have high energyFree up electrons—have high energy


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Types of cell respirationTypes of cell respiration

Aerobic Processes:Aerobic Processes: REQUIREREQUIRE oxygen to take place oxygen to take place A lot of energy available (efficient) A lot of energy available (efficient)

Anaerobic Processes:Anaerobic Processes: DO NOTDO NOT require oxygen to take place require oxygen to take place Get energy quickly (inefficient)Get energy quickly (inefficient)


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GlycolysisGlycolysis Involves breaking down 6-carbon Involves breaking down 6-carbon

sugarssugars Break sugars into pyruvic acid moleculesBreak sugars into pyruvic acid molecules

3-Carbon molecules3-Carbon molecules

This process is This process is ANAEROBICANAEROBIC No oxygen necessaryNo oxygen necessary

Occurs in the cytoplasm of cellsOccurs in the cytoplasm of cells

GlycolysisGlycolysis You will need to know this…You will need to know this…

GlycolysisGlycolysis

Just Kidding… Just Kidding…

GlycolysisGlycolysis Glycolysis also creates hydrogen ions Glycolysis also creates hydrogen ions

and free electronsand free electrons The whole point of respiration = high energyThe whole point of respiration = high energy

H H ++ ions bond with NAD ions bond with NAD++ to form to form NADH + H NADH + H ++

NADH carries electrons and H NADH carries electrons and H ++ ions ions

This process uses This process uses 2ATP 2ATP molecules molecules and creates and creates 4 ATP4 ATP molecules molecules

GlycolysisGlycolysis TOTAL ATP PRODUCTION:TOTAL ATP PRODUCTION:

Glycolysis Glycolysis Step 1Step 1 uses 2 ATP molecules uses 2 ATP molecules

Glycolysis Glycolysis Step 2Step 2 converts 4 ADP converts 4 ADP molecules into 4 ATP moleculesmolecules into 4 ATP molecules

Net ATP production = 2 ATP for every Net ATP production = 2 ATP for every glucose glucose

moleculemolecule


GlycolysisGlycolysis Oxygen is our friend…Oxygen is our friend…

When oxygen is present, When oxygen is present, aerobic respirationaerobic respiration occurs occurs

Happens in the mitochondriaHappens in the mitochondria

GlycolysisGlycolysis Breaking down Pyruvic Acid…Breaking down Pyruvic Acid…

Occurs in the mitochondriaOccurs in the mitochondria

Pyruvic Acid = 3-carbon compoundPyruvic Acid = 3-carbon compound

Broken down into…Broken down into… 2-Carbon compound—acetic acid2-Carbon compound—acetic acid Carbon DioxideCarbon Dioxide

GlycolysisGlycolysis Intermediate Step in GlycolysisIntermediate Step in Glycolysis

2-Carbon Compound—Acetic Acid2-Carbon Compound—Acetic Acid Combined with coenzyme A (CoA)Combined with coenzyme A (CoA) Forms compound called acetyl-CoAForms compound called acetyl-CoA

This is only an intermediate step—have This is only an intermediate step—have to move pyruvic acid into Krebs Cycleto move pyruvic acid into Krebs Cycle


Glycolysis =2 ATP


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Citric Acid (Krebs) CycleCitric Acid (Krebs) Cycle

Produces more ATP and releases Produces more ATP and releases more electronsmore electrons Electrons picked up by NAD Electrons picked up by NAD ++ and FAD and FAD

Organic carrier moleculesOrganic carrier molecules

Occurs inside mitochondriaOccurs inside mitochondria Mitochondrial MatrixMitochondrial Matrix


Acetyl CoA combines with a 4-carbon Acetyl CoA combines with a 4-carbon molecule to form a 6-carbon molecule to form a 6-carbon moleculemolecule

Citric AcidCitric Acid

Citric Acid broken down into a 5-Citric Acid broken down into a 5-carbon compoundcarbon compound

NAD NAD ++ removes electrons (NADH + H removes electrons (NADH + H ++)) COCO22 released released


5-carbon compound broken down into 5-carbon compound broken down into a 4-carbon compounda 4-carbon compound

ATP createdATP created NAD NAD + + removes electrons (NADH + H removes electrons (NADH + H ++)) COCO22 released released

4-carbon compound (oxaloacetic 4-carbon compound (oxaloacetic acid) is createdacid) is created

Used to bond with acetyl- CoA to restart cycleUsed to bond with acetyl- CoA to restart cycle


Citric Acid Cycle =

2 ATP



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Electron Transport ChainElectron Transport Chain What is the ETC???What is the ETC???

A series of molecules along which A series of molecules along which electrons are transferred, releasing electrons are transferred, releasing energyenergy

Occurs in the mitochondria—Occurs in the mitochondria—wall of mitochondriawall of mitochondria

Aerobic processAerobic process Oxygen is involvedOxygen is involved

Acts as the electron acceptorActs as the electron acceptor

Electron Transport ChainElectron Transport Chain

As the electrons are passed between As the electrons are passed between carrier proteins, energy is releasedcarrier proteins, energy is released ATP is createdATP is created

Electrons are given up by the carrier Electrons are given up by the carrier moleculesmolecules NADH and FADHNADH and FADH22 ------- NAD ------- NAD + + and FAD and FAD



As the electrons (H As the electrons (H ++ ions) travel ions) travel down the chain, they bond with down the chain, they bond with oxygenoxygen

2 H2 H + + + 1 O = water (H+ 1 O = water (H22O)O) Electron acceptorElectron acceptor

Carbon is given off as carbon dioxideCarbon is given off as carbon dioxide



ETC =34 ATP

Electron Transport ChainElectron Transport Chain A problem exists if there is no oxygenA problem exists if there is no oxygen

Anaerobic processAnaerobic process

When oxygen is used up, electrons When oxygen is used up, electrons cannot be removedcannot be removed

Traffic jam in the mitochondriaTraffic jam in the mitochondria

KEY POINTKEY POINT —Electron Transport —Electron Transport Chain Chain cannot run without cannot run without oxygenoxygen

Anaerobic RespirationAnaerobic Respiration If no oxygen present after glycolysis, If no oxygen present after glycolysis,

pyruvic acid can still be broken downpyruvic acid can still be broken down FermentationFermentation

2 ATP made during fermentation2 ATP made during fermentation

Uses electrons carried by NADH + HUses electrons carried by NADH + H ++

so that NADso that NAD++ can regenerate for can regenerate for glycolysisglycolysis

Anaerobic RespirationAnaerobic Respiration Two types of fermentationTwo types of fermentation

Lactic Acid FermentationLactic Acid Fermentation

Alcoholic FermentationAlcoholic Fermentation

Glucose2 Pyruvic

Acid2 Lactic

Acid

Glucose2 Pyruvic

Acid2 Ethanol + 2 CO2

Anaerobic RespirationAnaerobic Respiration Lactic Acid FermentationLactic Acid Fermentation

NADH produce during glycolysis transfers H NADH produce during glycolysis transfers H atoms to pyruvate reducing it to lactate.atoms to pyruvate reducing it to lactate.

Muscle fatigueMuscle fatigue When your muscle cells require more energy When your muscle cells require more energy

than can be producedthan can be produced Lack of oxygenLack of oxygen Lactic acid build up = muscle fatigueLactic acid build up = muscle fatigue

When oxygen is present, lactic acid breaks When oxygen is present, lactic acid breaks downdown

Anaerobic RespirationAnaerobic Respiration

Anaerobic RespirationAnaerobic Respiration Alcohol FermentationAlcohol Fermentation

Occurs in bacteria, plants and most Occurs in bacteria, plants and most animalsanimals

Can you think of a bacteria that is used Can you think of a bacteria that is used for fermentation???for fermentation???

Pyruvic Acid is converted into ethanol Pyruvic Acid is converted into ethanol and carbon dioxideand carbon dioxide

Dacrboxylate pyruvate , releasing CO2 Dacrboxylate pyruvate , releasing CO2 and forming 2-C compound called and forming 2-C compound called acetaldehyde.acetaldehyde.

NADH produced during glycolysis NADH produced during glycolysis transfers hydrogen atoms to transfers hydrogen atoms to acetaldehyde, reducing it to ethyl acetaldehyde, reducing it to ethyl alcohol.alcohol.

Basis for the production of beer, wine, Basis for the production of beer, wine, and other alcoholic beverages.and other alcoholic beverages.

Anaerobic RespirationAnaerobic Respiration


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General FormulaGeneral Formula

C6H12O6 + 6 O2 6 CO2 + 6 H2O

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cellular respiration