Embed Size (px)
Citation preview
Cellular Cellular RespirationRespiration
Chapter 7Chapter 7
Miss ColabelliMiss Colabelli
Biology CPABiology CPA
Cellular RespirationCellular Respirationo Complex process that our cells Complex process that our cells
make make ATPATP by breaking down by breaking down organicorganic compoundscompounds
o Organisms that use cellular Organisms that use cellular respiration are known as respiration are known as heterotrophsheterotrophs
Cellular RespirationCellular Respirationo Cellular Respiration is the Cellular Respiration is the
process that releases energy by process that releases energy by breaking down breaking down foodfood molecules molecules in the presence of in the presence of oxygenoxygen
o CC66HH1212OO66 + 6O + 6O226CO6CO22 + 6H + 6H22O + O + ATPATPo Same equation for photosynthesis Same equation for photosynthesis
JUST BACKWARDS!JUST BACKWARDS!
GlycolysisGlycolysiso Process where one molecule of Process where one molecule of
glucoseglucose is broken in half, is broken in half, producing two 3-carbon producing two 3-carbon molecules of molecules of pyruvicpyruvic acidacid
o Creates a small amount of Creates a small amount of ATPATP and and NADHNADH
o Process is Process is anaerobicanaerobico Does not require oxygenDoes not require oxygen
Aerobic RespirationAerobic Respirationo If If oxygenoxygen is present in cell is present in cell
environmentenvironment
o Pyruvic acid is broken down to Pyruvic acid is broken down to make a large amount of make a large amount of ATPATP
o If no oxygen is available for the If no oxygen is available for the pyruvic acidpyruvic acido FermentationFermentation
FermentationFermentation
o Releases Releases energyenergy from pyruvic from pyruvic acid acid withoutwithout oxygen oxygen
o Two typesTwo typeso Lactic AcidLactic Acido AlcoholicAlcoholic
Lactic Acid Lactic Acid FermentationFermentation
o Lactic Acid is produced by Lactic Acid is produced by musclesmuscles during during rapidrapid exercise exercise when the body cannot supply when the body cannot supply enough enough oxygenoxygen
Alcoholic Alcoholic FermentationFermentation
o Alcoholic fermentation is done by Alcoholic fermentation is done by yeastsyeasts and some and some microorganismsmicroorganisms
o Produces an Produces an alcoholalcohol & & Carbon Carbon dioxidedioxide
GlycolysisGlycolysiso Glucose Glucose 2 pyruvic acid 2 pyruvic acid
moleculesmolecules
o Step 1: Step 1: o Glucose molecule uses Glucose molecule uses twotwo ATP ATP
molecules to make a 6-carbon molecules to make a 6-carbon molecule with two molecule with two phosphatesphosphates
GlycolysisGlycolysis
o Step 2:Step 2:o Glucose molecule breaks in Glucose molecule breaks in
halfhalf to make two to make two G3PG3P moleculesmolecules
GlycolysisGlycolysiso Step 3:Step 3:
o Each G3P molecule gets a Each G3P molecule gets a phosphatephosphate added and 2 NAD+ added and 2 NAD+ are reduced and gain an are reduced and gain an electron to become NADHelectron to become NADH
GlycolysisGlycolysiso Step 4:Step 4:
o Each 3-Carbon molecule loses Each 3-Carbon molecule loses their phosphates to make 4 their phosphates to make 4 molecules of molecules of ATPATP, 2 molecules , 2 molecules of of waterwater, and 2 molecules of , and 2 molecules of pyruvicpyruvic acidacid
FermentationFermentationo AnaerobicAnaerobic process after process after
glycolysisglycolysis
o Pyruvic acid is used to become Pyruvic acid is used to become either either lacticlactic acidacid or or ethylethyl alcoholalcohol
o This process is important This process is important because it regenerates because it regenerates NAD+NAD+ molecules for glycolysis to molecules for glycolysis to continue to workcontinue to work
Lactic Acid Lactic Acid FermentationFermentation
o Pyruvic acid Pyruvic acid lactic acidlactic acid
o NADH NADH NAD+NAD+
o Important for making Important for making dairydairy products productso Produces certain Produces certain cheesescheeses and and yogurtsyogurts
o Occurs naturally in your Occurs naturally in your musclesmuscles when when you work outyou work outo Muscle sorenessMuscle soreness
Lactic Acid Lactic Acid FermentationFermentation
o Muscles use up all Muscles use up all available available oxygenoxygeno Switch to Switch to anaerobicanaerobic
respirationrespiration
o Increases Increases acidacid levels in muscles levels in muscles causing the fatiguecausing the fatigueo Eventually gets Eventually gets
processed in liver processed in liver back to pyruvic acidback to pyruvic acid
Lactic Acid Lactic Acid FermentationFermentation
Alcoholic Alcoholic FermentationFermentation
o Pyruvic acid Pyruvic acid ethyl alcoholethyl alcohol
o NADH NADH NAD+NAD+
o Ethyl alcohol is a Ethyl alcohol is a 2-carbon2-carbon moleculemoleculeo Pyruvic acid loses a carbon by Pyruvic acid loses a carbon by
releasing releasing COCO22
Alcoholic Alcoholic FermentationFermentation
o Yeast needs to get food to survive such Yeast needs to get food to survive such as as sugarssugars from fruit from fruit
o Yeast breaks down to Yeast breaks down to fermentferment the the pyruvic acid into pyruvic acid into ethylethyl alcoholalcohol and and COCO22
o If COIf CO22 is released, you get is released, you get regularregular alcohol alcohol
o Ex: wineEx: wine
o If COIf CO22 is is notnot released, you get released, you get sparklingsparkling alcoholalcoholo Ex: ChampagneEx: Champagne
Efficiency of Efficiency of GlycolysisGlycolysis
o Glycolysis uses Glycolysis uses 22 ATP in order to ATP in order to create G3P moleculescreate G3P molecules
o Makes Makes 44 ATP at the end of the ATP at the end of the processprocess
o As a process to make energy, the As a process to make energy, the efficiency is about efficiency is about 2%2%o Very Very lowlow for necessary energy for necessary energyo This is why we need This is why we need cellularcellular
respirationrespiration!!!!
The Krebs CycleThe Krebs Cycleo During the Krebs Cycle, pyruvic acid During the Krebs Cycle, pyruvic acid
is broken down into is broken down into carboncarbon dioxidedioxide in a series of energy-extracting in a series of energy-extracting reactionsreactions
o CitricCitric AcidAcid is created in this cycle is created in this cycle thus giving it the nickname Citric thus giving it the nickname Citric Acid cycleAcid cycle
o Net ATP Production is Net ATP Production is 22 ATP ATP
Electron Transport Electron Transport ChainChain
o The electron transport chain uses the The electron transport chain uses the high-energy high-energy electronselectrons from the Krebs from the Krebs Cycle to convert ADP to ATPCycle to convert ADP to ATP
o Total ATP produced: Total ATP produced: 3232
Aerobic RespirationAerobic Respiration
o Only occur in the presence of Only occur in the presence of oxygenoxygen
o Two stagesTwo stageso KrebsKrebs CycleCycleo ElectronElectron TransportTransport ChainChain with chemiosmosis with chemiosmosis
o ProkaryotesProkaryoteso Occur in Occur in cytosolcytosol
o EukaryotesEukaryoteso Occur in Occur in mitochondriamitochondria
Aerobic RespirationAerobic Respiration
o After glycolysis, After glycolysis, pyruvicpyruvic acidsacids are are producedproduced
o Pyruvic acid moves Pyruvic acid moves inside mitochondria inside mitochondria into into mitochondrialmitochondrial matrixmatrix (space between (space between two membranes)two membranes)
o Pyruvic acid + CoA Pyruvic acid + CoA Acetyl CoA + COAcetyl CoA + CO22
The Krebs CycleThe Krebs Cycleo Acetyl CoA Acetyl CoA COCO2 2 + H + ATP+ H + ATP
o The The HH produced reduce NAD+ produced reduce NAD+ NADHNADH
o FiveFive steps in the Krebs Cycle steps in the Krebs Cycleo Occurs in mitochondrial matrixOccurs in mitochondrial matrix
o Citric Acid is made in Step 1 therefore Citric Acid is made in Step 1 therefore this is also called the this is also called the CitricCitric AcidAcid cyclecycle
o Net ATP produced is Net ATP produced is 22 ATP ATP
Krebs Cycle - Step 1Krebs Cycle - Step 1
o Acetyl CoA + oxaloacetic acid Acetyl CoA + oxaloacetic acid Citric Citric AcidAcid
o This step releases This step releases CoACoA back into the back into the mitochondrial matrix for pyruvic acid to mitochondrial matrix for pyruvic acid to be fixed againbe fixed again
Krebs Cycle – Step 2Krebs Cycle – Step 2o Citric acid releases Citric acid releases COCO22 and and H H
o Becomes a Becomes a 5-carbon5-carbon compound compound
o The H released, reduces the NAD+ The H released, reduces the NAD+ to to NADHNADH
Krebs Cycle – Step 3Krebs Cycle – Step 3
o Five carbon compound releases Five carbon compound releases another another COCO22 and and HH
o Becomes a Becomes a 4-Carbon4-Carbon compound compound
o Another NAD+ is reduced to Another NAD+ is reduced to NADHNADH
o Produces an Produces an ATPATP
Krebs Cycle – Step 4Krebs Cycle – Step 4o 4 carbon compound releases 4 carbon compound releases HH atom atom
o This time, FAD is reduced to This time, FAD is reduced to FADHFADH22
o Similar molecule to NAD+Similar molecule to NAD+
Krebs Cycle – Step 5Krebs Cycle – Step 5o 4-Carbon compound releases 4-Carbon compound releases HH atom atom
o Reduces NAD+ to Reduces NAD+ to NADHNADH
o This reaction regenerates initial This reaction regenerates initial oxaloaceticoxaloacetic acidacid
Don’t let this happen to Don’t let this happen to YOU!YOU!
Electron Transport Electron Transport ChainChain
o Uses the high-energy Uses the high-energy electronselectrons from from the Krebs Cycle to convert ADP to the Krebs Cycle to convert ADP to ATPATP
o Total net ATP produced is Total net ATP produced is 3434!!!!
o ProkaryotesProkaryoteso Occurs on Occurs on cellcell membranemembrane of organism of organism
o EukaryotesEukaryoteso Occurs in the Occurs in the mitochondria mitochondria
membrane called membrane called cristaecristae
ETC – Step 1ETC – Step 1
o NADHNADH & & FADHFADH22 are used to are used to power this chain of reactionspower this chain of reactions
o NADH & FADHNADH & FADH22 are are oxidizedoxidized (lose electrons) to the (lose electrons) to the electron transport chainelectron transport chaino Also donate H atoms Also donate H atoms o NADH NADH NAD+NAD+
o FADHFADH22FAD+FAD+
ETC – Step 2ETC – Step 2o ElectronsElectrons from NADH & FADH from NADH & FADH22
are passed down chainare passed down chaino Lose some Lose some energyenergy each time each time
passed onpassed on
ETC – Step 3ETC – Step 3o Lost energy from electrons Lost energy from electrons
transferring down the chain transferring down the chain pumppump protons (Hprotons (H++))
o This creates This creates highhigh concentration of H concentration of H++ between inner and outer membranesbetween inner and outer membraneso Creates a Creates a concentrationconcentration gradientgradient & &
electricalelectrical gradientgradient since H since H++ are positive are positive
ETC – Step 4ETC – Step 4o Concentration & electrical gradients Concentration & electrical gradients
in membranes produce in membranes produce ATPATP molecules by molecules by chemiosmosischemiosmosis
o ATP ATP synthasesynthase is protein embedded in is protein embedded in membrane that pumps protons out membrane that pumps protons out and creates ATPand creates ATP
ETC – Step 5ETC – Step 5o The electrons move to The electrons move to finalfinal acceptoracceptor
down the chaindown the chaino OxygenOxygen is the final acceptor is the final acceptor
o Oxygen also accepts Oxygen also accepts protonsprotons provided by NADH & FADHprovided by NADH & FADH22
o The protons, electrons, and oxygen The protons, electrons, and oxygen all combine to produce all combine to produce HH22OO
Importance of OxygenImportance of Oxygeno The only way to produce ATP is The only way to produce ATP is
by the movement of electrons in by the movement of electrons in the the ETCETCo OxygenOxygen is the final acceptor is the final acceptor
o Without oxygen, the ETC would Without oxygen, the ETC would halthalt
Efficiency of Cellular Efficiency of Cellular RespirationRespiration
o Glycolysis Glycolysis 22 ATP ATP
o Krebs Cycle Krebs Cycle 22 ATP ATP
o Electron Transport Chain Electron Transport Chain 3232 ATP ATP
o Total = Total = 3636 ATP ATP
Efficiency of Efficiency of Cellular Cellular
RespirationRespirationo Depends on Depends on conditionsconditions of the of the
cellcell
o How How ATPATP are transported are transported
o Aerobic respiration is Aerobic respiration is 2020 times times more efficient than more efficient than anaerobicanaerobic respirationrespiration
SummarySummary
o Cellular respirationCellular respirationo GlycolysisGlycolysis
o Glucose Glucose pyruvicpyruvic acidacid + + ATPATP + + NADHNADH
o Aerobic respirationAerobic respiration
o Pyruvic acid Pyruvic acid COCO22 + + HH22OO + + ATPATP
Comparing Photosynthesis & Comparing Photosynthesis & RespirationRespiration
PhotosynthesisPhotosynthesis Cellular Cellular RespirationRespiration
FunctionFunction Energy StorageEnergy Storage Energy ReleaseEnergy Release
LocationLocation ChloroplastsChloroplasts MitochondriaMitochondria
Reactants Reactants COCO22 and H and H22OO CC66HH1212OO66 and O and O22
ProductsProducts CC66HH1212OO66 and O and O22 COCO22 and H and H22OO
EquationEquation 6CO6CO22 + 6H + 6H22O O CC66HH1212OO66 + 6O + 6O22
CC66HH1212OO66 + 6O + 6O22
6CO6CO22 + 6H + 6H22OO
