Chapter 9 Cellular Respiration Friday October 16 2015 8 12 AM Fermentation and Cellular Respiration Fermentation without oxygen Cellular respiration with oxygen Cellular respiration C6H12O6 6CO2 6H2O Energy ATP heat The breakdown of glucose to CO2 H2O is exergonic Has free energy change G 686 kcal mol Involves oxidation reduction reaction Redox Oxidation is always coupled to reduction they occur together X e Y o o X Y e Oxidizing agent becomes reduced Reducing agent becomes oxidized Na Cl o Na Cl LEO SAYS GER LEO Lose Electrons Oxidation Na o Na e Sodium is oxidized GER Gain Electrons Reduction Discussing the reactants Electronegative Elements Trend increase left to right bottom to top Higher potential energy Combustion lots of energy Redox reaction presence of electron movement CH4 2O2 CO2 Energy 2H2O Electrons are moving toward oxygen oxygen gain electrons and being reduced Extraction of Energy from Glucose During Cellular Respiration Cellular respiration C6H12O6 o o 6CO2 6H2O Energy ATP heat Carbon has lower electron affinity electronegativity Glucose low electron affinity o Oxygen high electron affinity o Glucose oxidized to carbon dioxide o Oxygen reduced to water Glucose high potential energy molecule C H bonds include electrons in covalent bonds with lower polarity Carbon dioxide low potential energy C O bonds include electrons in covalent bonds with higher polarity Potential energy of molecule potential energy of molecule Q1 When electrons move closer to a more electron negative atom a Energy is consumed b Energy is released c The more electron negative atom is oxidized d The more electron negative atom is reduced gained atom e B and D only Electron movement is from hydrogen NAD NADH Glycolysis sugar split o NAD ADP split glucose o Into 2 pyruvate ATP NADH o Takes place in cytoplasm Citric acid cycle o 2 pyruvate into 6 carbon dioxide CO2 o Reduced forms of electron carriers NADH FADH2 carrying electrons with high potential energy o Takes place in mitochondria Carry onto electron transport chain ETC o Requires oxygen o Approximately 36 38 ATP o Takes place in mitochondria cristae inner membrane of mitochondria Where are the citric acid cycle and oxidative phosphorylation happening 1 Glucose split into 2 pyruvate ATP produced Oxidized glucose electron carriers generated via NADH Pyruvate completely oxidized into CO2 within citric acid cycle Electron carriers Reduced form of electron carriers will be delivered to ETC where electrons will be stripped electron potential energy will be used to produce more ATP Purpose of All these processes This is catabolic metabolism The purpose is to convert the potential energy of glucose into the potential energy of ATP to do cellular work CO2 low potential energy CO bond so close to As glucose turns into carbon dioxide captured by ATP used to synthesize ATP Glycolysis Contains 10 enzyme catalyzed chemical reactions in sequence o Input 2 ATP 2 NAD glucose o Output 2 molecules of pyruvate 2 NADH 4 ATP NET GAIN of ATP 2 ATP how many ATP produced from glycolysis o 2 steps Energy Investment Phase Energy Payoff Phase harvest ATP o ATP produced within substrate level phosphorylation Bookkeeping o 2 ATP were invested in first phase of glycolysis o 4 ATPs per original glucose producedi n 2nd phase o 2 molecules of NADH also produced o Glycolysis INVEST 2 ATP produce 4 ATP Net 2 ATP 2 NADH Substrate level phosphorylation o Organic phosphate attached Energy yield from glycolysis o Glucose 6 CO2 686 kcal mole o 2 ATPs produced 2 x 7 3 14 6 14 6 kcal mole o Energy yield 14 6 686 0 0213 2 recovered as ATP o Subsequent oxidation of pyruvate and NADH can recover more of the free energy from glucose Citric Acid Cycle Q4 How many carbon dioxide molecules from 2 pyruvate 4 rounds o 8 For each glucose that enters glycolysis we have a net gain of 4 ATP molecules o 2 from glycolysis o 2 from citric acid cycle 10 NADH molecules o 2 from glycolysis o 2 from conversion of pyruvate to acetyl Co A strip carbon from pyruvate o 6 from the oxidation of acetyl Co A in the citric acid cycle 2FADH2 molecules o 2 from the citric acid cycle 6CO2 molecules o 2 from the conversion of pyruvate to acetyl Co A o 4 from the oxidation of acetyl Co A in the citric acid cycle what is produced rom citric acid cycle what is produced from two molecules of glucose Q 5 For every 5 molecules of glycose metabolized through glycolysis and citric acid cycle how many NADH will be produced o 50 Electron transport chains allow for a controlled release of energy Uncontrolled reaction H2 1 2 O2 Explosive release of heat and light energy H2O The electrons carried on the NADH and FADH2 are passed to a chain of protein metal complexes called electron transport chain o Enter ETC from different positions o NADH enter with higher potential energy enter from the very beginning of ETC o FADH enters within the middle of ETC o As you go down higher electronegativity That s why it is possible for electrons to move down Work as proton pumps across the membrane o Decreases as they pass through Intermembrane space higher protein concentration Inner mitochondrial membrane Mitochondrial matrix lower protein concentration Membrane is not permeable to proton Make a concentration protein difference across the membrane and that difference has potential energy proton motive force o Drives ATP synthesis Mitochondrial matrix ATP synthase has two parts Intermembrane space allows proton to move through Rotor works as ATP synthase catalyze real ATP synthesis drive ATP synthesis Oxidative phosphorilation ATP made from ADP Grab one substrate to another Here use inorganic phosphate Each NADH can produce 2 5 ATP Each FADH can produce 1 5 ATP 7 3 x 38 686 40 the rest of the energy are relased as heat Aerobic cell Resp most effective way of energy conversion Harvest most energy from molecule glucose Q6 location input output Where are the proteins of ETC located Inner membrane of mitochondria Q7 How many ATP are produced per second per cell 10 million Fermentation No oxygen present Pyruvate oxidizes NAD NADH Manage a way to produce pyruvate and NAD to keep glycolysis going Fuel Available for Catabolic Reactions Main pathway of the cell to obtain energy o Carbohydrates converted to glucose and goes through glycolysis o Protein chopped down into amino acids First amino group is stripped amino group attached to urea stripped to produce urea Carbon skeleton goes into different stages of cellular respiration Enters cellular o