Post on 22-Dec-2015
transcript
Cellular RespirationCellular Respiration
Chapter 9Chapter 9
Overview of CROverview of CR
Reverse process of photosynthesisReverse process of photosynthesis
Photosynthesis: energy Photosynthesis: energy → food→ food
Respiration: food → energyRespiration: food → energy
Overview of CROverview of CR
Occurs in all organismsOccurs in all organisms– In eukaryotes – mitochondriaIn eukaryotes – mitochondria– In prokaryotes – cytoplasmIn prokaryotes – cytoplasm
Two types:Two types:– Aerobic – needs OAerobic – needs O22
– Anaeobic – does not need OAnaeobic – does not need O22
What do cells need E for?What do cells need E for?
MovementMovement
Cellular transportCellular transport
GrowthGrowth
Muscle contractionMuscle contraction
Aerobic Resp. ReactionAerobic Resp. Reaction
Sugar and oxygen are converted into Sugar and oxygen are converted into water, carbon dioxide and 36 ATP water, carbon dioxide and 36 ATP moleculesmolecules
ATP = useable energyATP = useable energy
ATPCOOHOOHC 36666 2226126
Steps of Aerobic Resp.Steps of Aerobic Resp.1.1. Glycolysis – in cytoplasmGlycolysis – in cytoplasm
2.2. Kreb’s Cycle – in mitochondriaKreb’s Cycle – in mitochondria
3.3. Electron Transport Chain – in mitochondriaElectron Transport Chain – in mitochondria
GlycolysisGlycolysis
Glyco-: sugar -lysis: breakGlyco-: sugar -lysis: break
Makes 4 ATP, uses 2 ATP = 2 ATPMakes 4 ATP, uses 2 ATP = 2 ATP
Produces 2 NADH (electron carrier)Produces 2 NADH (electron carrier)
Kreb’s CycleKreb’s Cycle
Pyruvic acid broken down into COPyruvic acid broken down into CO2 2
moleculesmolecules– Produces 2 ATP, several NADH and Produces 2 ATP, several NADH and
FADHFADH22 molecules (more school buses for molecules (more school buses for ee-- and H and H++))
Kreb’s Kreb’s CycleCycle
Electron Transport ChainElectron Transport Chain
Same concept as in photosynthesisSame concept as in photosynthesis
Electrons from NADH and FADHElectrons from NADH and FADH22 pass pass down a chain of moleculesdown a chain of molecules– Energy released used to pump HEnergy released used to pump H++ into into
intermembrane spaceintermembrane space– HH++ diffuse back into matrix through ATP diffuse back into matrix through ATP
synthasesynthase
Yields 34 ATP/glucoseYields 34 ATP/glucose
Why do we need OWhy do we need O22??
At end of ETC, eAt end of ETC, e-- “caught” by O “caught” by O22
– combines with Hcombines with H++, makes H, makes H22OO
No ONo O22 means e means e-- has no where to go has no where to go
ETC backs up with electronsETC backs up with electrons
Respiration stops = deathRespiration stops = death
ETCETC
What happens when no OWhat happens when no O22 is is
available??available??
Fermentation or Anaerobic Resp.Fermentation or Anaerobic Resp.Occurs after glycolysisOccurs after glycolysisRegenerates empty NADRegenerates empty NAD+ + so that so that glycolysis can continueglycolysis can continueTwo types:Two types:– Alcohol ferm.Alcohol ferm.
In plants, fungiIn plants, fungi
– Lactic acid ferm.Lactic acid ferm.In animalsIn animals
Alcohol FermentationAlcohol Fermentation
Pyruvic acid + NADH Pyruvic acid + NADH → Ethanol + CO→ Ethanol + CO22+ NAD+ NAD++
Produces alcohol for beveragesProduces alcohol for beverages
COCO22 produced by yeast makes bread produced by yeast makes bread riserise
Lactic Acid FermentationLactic Acid Fermentation
Pyruvic acid + NADHPyruvic acid + NADH→ lactic acid + NAD→ lactic acid + NAD++
Creates burning sensation in muscles during Creates burning sensation in muscles during intense exerciseintense exercise
PhotosynthesisPhotosynthesisvs. Cellular Respirationvs. Cellular Respiration
ATPCOOHOOHC 36666 2226126
2612622 666 OOHCOHCO light
ATPGlucoseyLightEnerg nRespiratioesisPhotosynth