cellular respiration. energy flow photosynthesis –carried out by plants uses energy from sunlight...
TRANSCRIPT
![Page 1: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/1.jpg)
Cellular Respiration
![Page 2: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/2.jpg)
Energy Flow• photosynthesis
– carried out by plants
• uses energy from sunlight
• converts into glucose & oxygen
• used in cellular respiration
• oxygen is consumed • glucose is broken
down CO2 & H2O
![Page 3: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/3.jpg)
Respiration• means breathing
• cellular respiration
– exchange of gases
• O2 from environment is used & CO2 is released & removed by blood
![Page 4: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/4.jpg)
Cellular Respiration• provides ATP for cellular work
• called oxidation
• oxidizes food molecules, like glucose, to CO2 & water
• 6C6H12O2 + 6O2 6CO2 + 6H2O + ATP
• energy is trapped in ATP
![Page 5: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/5.jpg)
Cellular Respiration-Oxidation• electrons are transferred from sugar to
O2 making H2O• do not see electron transfer in equation• see changes in H ions• glucose molecule loses hydrogen
atoms as it is converted to CO2 • O2 gains hydrogen atoms to form water• O2 is an electron grabber
– pulls harder than other atoms to get electrons
• these hydrogen movements represent electron transfers
• each hydrogen atom consists of one electron and one proton
• electrons move along with hydrogens from glucose to O2
• it is as if they are falling• energy is released in the process• process is possible only because of O2
• if you stop breathingno ATP would be madeall processes stopdeath
6C6H12O2 + 6O2 6CO2 + 6H2O + ATP
![Page 6: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/6.jpg)
Complete Oxidation of Glucose• C6H12O6 + 6O2 6CO2 + 6H2O
• for one thing to be oxidized-another must be reduced
• oxidation & reduction reactions occur together
• redox reactions
![Page 7: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/7.jpg)
Oxidation/Reduction Reactions• Oxidation
– H+ atoms are removed from compounds
• Oxidized things lose electrons• electron lostoxidized-loses
energy• Reduction
– H+ atoms are added to compounds
• gain electronreduced-gains energy
• food fuels are oxidized-lose energy transferred to other moleculesATP
• coenzymes act as hydrogen or electron acceptors– reduced each time substrate
is oxidized
![Page 8: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/8.jpg)
CoEnzymes• NAD+-niacin-nicotinamide adenine dinucleotide• FAD-flavin adenine dinucleotide-riboflavin
![Page 9: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/9.jpg)
Glucose Oxidation Steps• Glycolysis
– occurs in cytosol– does not require oxygen– also called anaerobic
• Kreb’s Cycle– occurs in mitochondria
– require O2
– aerobic
• Electron Transport Chain– occurs in mitochondria
– require O2
– aerobic
![Page 10: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/10.jpg)
Glycolysis• first step in complete
oxidation of glucose• occurs in cytosol• begins when enzyme
phosphorylates glucose– adds PO4 group to
glucose Glu6PO4• traps glucose• reaction uses 2 ATPs• Energy Investment
Phase
![Page 11: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/11.jpg)
Glycolysis• Sugar Splitting
Stage
• 6 carbon compound2 pyruvates (3 carbon compounds)
ATP
![Page 12: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/12.jpg)
Glycolysis
![Page 13: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/13.jpg)
Pyruvate• fate depends on oxygen
availability• not enough oxygen
– NAD+ is regenerated by converting pyruvatelactic acid
• anaerobic fermentation• O2 available• pyruvic acid enters
aerobic pathways of Krebs cycle
• aerobic respiration
![Page 14: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/14.jpg)
Anaerobic Fermentation• not enough oxygen• NAD+ regenerated by
converting pyruvatelactic acid
• limited by buildup of lactic acid– produces acid/base
problems– degrades muscle
performances• used for short bursts of high
level activity lasting several minutes
• cannot supply ATP for long, endurance activities
![Page 15: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/15.jpg)
Alcohol Fermentation• yeast without
oxygen
• provides ATP
• by product-ethanol
• regenerates NAD+
![Page 16: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/16.jpg)
Aerobic Respiration• pyruvic acid enters
mitochondria• once inside converted
acetyl CoA• during conversion• pyruvate is
decarboxylated (carbons removed) released as CO
• pyruvic acid + NAD + + coenzyme A CO2 + NADH + Acetyl CoA
![Page 17: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/17.jpg)
Krebs Cycle• acetyl CoA enters Krebs Cycle
– tricarboxylic acid cycle or Citric Acid Cycle
• during cycle hydrogen atoms are removed from organic moleculestransferred to coenzymes
• cycle begins & ends with same substrate: oxaloacetate (OAA)
• acetyl CoA condenses with oxaloacetate- 4 carbon compoundcitrate-6 carbon compound
• cycle continues around through 8 successive step
• during steps atoms of citric acid are rearranged producing different intermediates called keto acids
• eventually turns into OAA
![Page 18: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/18.jpg)
Krebs Cycle• Yields
– 2 CO2
– reducing equivalents-3 NADH & 1 FADH2
• further oxidized in electron transport chain
– 1 GTP-ATP equivalentSince two pyruvates are
obtained from oxidation of glucose amounts need to be doubled for complete oxidation results
![Page 19: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/19.jpg)
Electron Transport Chain• transfers pairs of electrons
from entering substrate to final electron acceptor-oxygen
• electrons are led through series of oxidation-reduction reactions before combining with O2 atoms
• reactions takes place on inner mitochondrial membrane
• only permeable to water, oxygen & CO2
![Page 20: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/20.jpg)
Oxidative Phosphorylation/Electron Transport Chain System
• responsible for 90% of ATP used by cells
• basis-2H + O22 H20• releases great deal of energy all at
once• cells cannot handle so much energy
reactions occur in series of steps • Oxidation reactions
– remove H+ atoms & lose energy (H+)• Oxidized things lose electrons• compounds that gain electrons
reduced-gain energy• enzymes cannot accept H atoms• Coenzymes needed to accept
hydrogens • when coenzyme accepts hydrogen
atoms coenzyme reduced & gains energy
![Page 21: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/21.jpg)
Chemiosmosis• ETC creates conditions needed for ATP
production by creating concentration gradient across inner mitochondrial membrane
• as energy is released-as electrons are transferred drives H ion pumps that move H across membrane into space between 2 membranes
• pumps create large concentration gradients for H
• H ions cannot diffuse into matrix because not lipid soluble
• channels allow H ions to enter matrix• Chemiosmosis
– energy released during oxidation of fuels=chemi
– pumping H ions across membranes of mitochondria into inter membrane space =osmo
– creates steep diffusion gradient for Hs across membrane
• when hydrogens flow across membrane, through membrane channel proteinATP synthase attaches PO4 to ADP ATP
ATP synthase
![Page 22: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/22.jpg)
Oxidative Phosphorylation• for each pair
of electrons removed by NAD from substrate 3 ATPs are made
• FAD2 ATPs are made
![Page 23: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/23.jpg)
![Page 24: Cellular Respiration. Energy Flow photosynthesis –carried out by plants uses energy from sunlight converts into glucose & oxygen used in cellular respiration](https://reader035.vdocuments.us/reader035/viewer/2022070400/56649f0d5503460f94c21e75/html5/thumbnails/24.jpg)
Energy Yield • aerobic metabolism generates
more ATP per mole of glucose oxidized than anaerobic metabolism
• Glycolysis– net 2 ATPs
• Krebs Cycle– 2 ATP– 8 NADH + H+ X 3=24 ATP– 2 FADH2 X 2=4 ATP
• 2 moles pyruvate2 NADH + H+-glycolysis 2 X 2 = 4 ATP
• Total 36 ATP