Presentation on theme: "Glycolysis and Cellular Respiration"— Presentation transcript:
1 Glycolysis and Cellular Respiration Harvesting EnergyGlycolysis and Cellular Respiration
2 Energy from GlucoseGlycolysis and Cellular Respiration break glucose and other carbon compounds apart.Energy released from broken bonds is harnessed to make ATP to run cell processes.ALL Eukaryotic organisms (including plants) carry out cellular respiration ALL THE TIME.
3 Cellular respiration takes place in the mitochondria. mitochondrionoutermembraneintermembranespaceinnermembranematrixcristae
4 ATP is produced in great quantities by mitochondria. Remember ATP?Adenosine triphosphate, the universal energy carrier, is a single nucleotide (adenine) with two extra phosphate groups attached.ATP is produced in great quantities by mitochondria.
5 Review: ATP is produced and used in coupled reactions glucoseexergonic(glucose breakdown)endergonic(ATP synthesis)proteinexergonic(ATP breakdown)endergonic(protein synthesis)CO2 + H2O + heatADP + heataminoacidsnet exergonic“downhill” reaction
6 OverviewGlycolysis splits sugar into two 3-carbon chains (pyruvate), producing 2 ATPsglucose2 NADHglycolysis2 ATP(cytosol)2 pyruvate2 NADH2 acetyl CoACellular respiration breaks the sugar down further, producing ATPs.6 NADHKrebs(citric acid)cycle2 ATP(mitochondrion)2 FADH2electron transport chain32 or 34ATPsTotal 36 or 38ATPsNADH and FADH (derived from vitamins B3 and B2) act as electron carriers.
7 in cytosol– no oxygen required 2 ATP if no O2 available ethanol + CO2 glucosein cytosol–no oxygen requiredglycolysis2 ATPif no O2 availableethanol + CO2orlactic acidpyruvatefermentationin mitochondria–oxygen requiredCO2cellular respiration34 or 36ATPO2H2O
8 Glucose is split in half. Net gain of 2 ATPs Glycolysisin cytosol2ATP2ADP4ADP4ATP22glucoseG3Ppyruvatefructosebisphosphate2NAD+2NADH1 Glucose activation2 Energy harvestGlucose is split in half.Net gain of 2 ATPs2 ATPs are used.End product is pyruvateWhat 3-carbon compound here have we seen before?
10 Main points of glycolysis 6-carbon sugar is split into 3-carbon pyruvate.2 molecules of ATP are required for glycolysis, while 4 are produced, for a net gain of 2 ATPs.Glycolysis supplies some energy, its product (pyruvate) can be broken down further.
11 Cellular respiration begins with moving the products of glycolysis into the mitochondrion. 1 Formation ofacetyl CoA3NADH3NAD+FADFADH2CO2coenzyme AcoenzymeACoA2 Krebscycle2CO2acetyl CoApyruvateNAD+NADHADPIn cytosolATPIn mitochondrionKrebs Cycle Animation
13 Electron carriers from the Krebs cycle are used to power an electron transport chain and proton pump.Oxygen is requiredto accept energy-depleted electrons.Flow of H+ downconcentration gradientpowers ATP synthesis.High-energy electron carriersfrom acetyl CoA formation, Krebscycle, and glycolysis feed into the ETC.NADHFADH21/2O22e–2H+H2OADP+PiATPFADmatrixNADinnermembraneintermembranespaceEnergy fromhigh-energy electronspowers activetransport of H+ by ETC.High H+ concentration isgenerated by active transport.H+ channel is coupled toATP synthesizing enzyme.
15 Main points of cellular respiration Cellular respiration takes place in the mitochondria.The product of glycolysis is broken down completely, releasing CO2 as a waste gas.The electron transport chain/proton pump complex uses energized electrons to produce up to 36 ATPs from each molecule of glucose.
16 glucose(cytosol)In the absence of oxygen, cellular respiration cannot continue. Pyruvate from glycolysis is fermented, producing lactic acid or ethanol.2 NADHglycolysis2 ATPCellular respiration requires oxygen to pick up electrons and protons at the end of an electron transport chainlactate2 pyruvateorfermentation(no O2)ethanol + CO2cellular respiration2 NADH2 CO22 acetyl CoAKrebs(citricacid)cycle4 CO22 ATPH2O6 NADH1/2O22H+2 FADH22e–32 or 34ATPselectron transport chain(mitochondrion)
17 If the mitochondria can’t accept pyruvate, NADH from glycolysis accumulates, depleting NAD+. Fermentation uses excess NADH to convert pyruvate to lactic acid or ethanol.regenerationNAD+NADHNADHNAD+NADH22(glycolysis)(fermentation)glucosepyruvatelactate2ADP2ATP
18 Other monomers can be broken down for energy as well. Fatty acids have more energy per gram than sugars, so are preferred as energy storage.Other monomers can be broken down for energy as well.(cytosol)complexcarbohydratesfatsproteinsglucoseaminoacidsglycerolGlycolysisfatty acidspyruvateacetylCoAWhile brain cells usually must have glucose, other cells can use fatty acids and amino acids for energy.Amino acids must be stripped of nitrogen first, which is disposed of in the kidneys.KrebscycleelectroncarriersElectrontransport chainsynthesis(mitochondrion)breakdown
19 What if you take in more monomers than you need to produce ATP? Simple sugars are broken apart in glycolysis. If the mitochondria does not need Acetyl CoA, the acetate is released and can be used to synthesize fatty acids to make fats for storage.
20 Amino acids not needed for protein synthesis are stripped of their amine groups. The remaining carbon backbone can either be used to make Acetyl CoA, or can be used to synthesize fatty acids.
21 While animals can only do cellular respiration, plants make “food” using photosynthesis and break the “food” down for energy in cellular respiration.(chloroplast)photosynthesisH2OCO2ATPsugarO2cellularrespiration(mitochondrion)
22 AnimalsPlantsPhotosynthesisCellular RespirationCellular RespirationDayDayNightNightPhotosynthesis supplies the “food” that plants need to carry out cellular respiration.
23 RecapCellular respiration breaks organic compounds down into inorganic compounds.In the process, chemical energy in compounds such as sugar is converted to chemical energy in ATP.ATP is used to run cellular processes.ALL Eukaryotic organisms carry out cellular respiration.