Cellular Respiration How Cells Harvest Chemical Energy – Cellular Respiration.

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Cellular RespirationHow Cells Harvest Chemical Energy Cellular RespirationCellular RespirationC6H12O6 + 602 6CO2 + 6H20A catabolic pathwayOxygen is consumed as a reactant along with organic compounds.Involves three stages:GlycolysisKrebs CycleElectron Transport ChainWhat Is ATP?Adenosine TriphosphateEnergy used by all CellsOrganic molecule containing high-energy Phosphate bondsChemical Structure of ATPWhat Does ATP Do for You?It supplies YOU with ENERGY!How Do We Get Energy From ATP?By breaking the high- energy bonds between the last two phosphates in ATPNADH and FADH2NAD+ traps electrons from glucose to make NADH (energy stored)Similarly, FAD+ stores energy as FADH2Where Does Cellular Respiration Take Place?It actually takes place in two parts of the cell:Glycolysis occurs in the CytoplasmKrebs Cycle & ETC Take place in the MitochondriaReview of Mitochondria StructureSmooth outer MembraneFolded inner membraneFolds called CristaeSpace inside cristae called the MatrixDiagram of the ProcessOccurs in CytoplasmOccurs in MatrixOccurs across CristaeGlycolysis 1. Means splitting of sugar2. Occurs in the cytosol of the cell3. Partially oxidizes glucose (6C) into two pyruvate (3C) molecules.4. Occurs whether or not oxygen is present.5. An exergonic process, (meaning energy is released) most of the energy harnessed is conserved in the high-energy electrons of NADH and in the phosphate bonds of ATPGlycolysis SummaryTakes place in the CytoplasmAnaerobic (Doesnt Use Oxygen)Requires input of 2 ATPGlucose split into two molecules of PyruvateAlso produces 2 NADH and 4 ATPFormation of Acetyl CoA1. Junction between glycolysis and Krebs cycle2. Oxidation of pyruvate to acetyl CoA3. Pyruvate molecules are translocated from the cytosol into the mitochondrion by a carrier protein in the mitochondrial membrane.4. A CO2 is removed from pyruvate making a 2C compound.5. Coenzyme A is attached to the acetyl group.Formation of Acetyl CoAFormation of Acetyl CoAKrebs CycleRequires Oxygen (Aerobic)Cyclical series of oxidation reactions that give off CO2 and produce one ATP per cycleTurns twice per glucose moleculeProduces two ATP Takes place in matrix of mitochondriaKrebs Cycle SummaryEach turn of the Krebs Cycle also produces 3NADH, 1FADH2, and 2CO2Therefore, For each Glucose molecule, the Krebs Cycle produces 6NADH, 2FADH2, 4CO2, and 2ATPElectron Transport Chain 1. Located in the inner membrane of the mitochondria.2. Oxygen pulls the electrons from NADH and FADH2 down the electron transport chain to a lower energy state. 3. Process produces 34 ATP or 90% of the ATP in the body.Electron Transport Chain4. Requires oxygen, the final electron acceptor.5. For every FADH2 molecule 2 ATPs are produced.6. For every NADH molecule 3 ATPs are produced.7. Chemiosmosis the production of ATP using the energy of H+ gradients across membranes to phosphorylate ADP.ATP SynthaseA protein in the inner membrane in the mitochondria.Uses energy of the ion gradient to power ATP synthesis.For every H+ ion that flows through ATP synthase, one ATP can be formed from ADPCellular Respiration in Summary Glycolysis2 ATP2 NADH 4-6 ATP (Depends on how this NADH molecule gets to the ETC. To make things simple we will say that these two NADHs make 4 ATP )Formation of Acetyl CoA2 NADH 6 ATPCellular Respiration in SummaryKrebs Cycle2 ATP6 NADH 18 ATP2 FADH2 4 ATPGrand Total = 36 ATPFermentationOccurs when O2 NOT present (anaerobic)Called Lactic Acid fermentation in muscle cells (makes muscles tired)Called Alcoholic fermentation in yeast (produces ethanol)Nets only 2 ATP


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