CELLULAR RESPIRATION Process of oxidizing glucose to CO2 and H2O chemical energy released and partially captured in the form of ATP Equation C H O 6O 6CO 6H O energy Glucose oxygen Carbon dioxide water energy ATP Catabolic reaction releases heat as a by product Occurs in 3 processes In absence of oxygen fermentation complements glycolysis 1 Glycosis Breakdown of glucose 6 carbon sugar to pyruvic acid two 3 carbon a Occurs in the cytoplasm of cell b Anaerobic process c All steps reversible except 1st step of phosphorylation 1 PHOSPHORYLATION 1 Glucose ATP G6P glucose 6 phosphate 2 G6P F6P fructose 6 phosphate 2 F6P ATP Fructose 1 6 diphosphate 3 Fructose 1 6 diphosphate two PGAL 3 carbon chains 4 PGAL oxidized electrons picked up by NAD 5 DEPHOSPHORYLATION 1 ADP phosphate group ATP 2 ADP phosphate group second ATP d PRODUCTS i ii iii 2 pyruvates 2 ATP net 2 NADH H lactic acid as glycolysis Fermentation anaerobic respiration in absence of oxygen results in Does not enter mitochondria for further breakdown goes only as far Pyruvic acid reduces NADH Lactic acid NAD recycles PRODUCTS 2 lactates 2 ATP 2 NAD from reducing NADH Transition Reaction Pyruvic acid transported to mitochondria acetyl CoA a Occurs in the mitochondria b PRODUCTS i 1 NADH ii 1 CO2 first production of CO2 from fuel catabolism iii Acetyl coA c Carbohydrates converted into acetyl CoA from glycolysis d Fatty acids converted into acetyl CoA from beta oxidation pathway 1 Pyruvic acid oxidized and releases CO2 via dehydrogenase 2 carbon acetate 2 Energy released from oxidation either a 2 e NAD NADH b Acetate CoA Acetyl CoA 2 Krebs Cycle citric acid cycle Creates ATP NADH and FADH2 from oxidation of pyruvate a Occurs in matrix of mitochondria b Each glucose molecule 2 cycles to break down two pyruvate molecules 1 2 carbon acetyl CoA 4 carbon oxaloacetate 6 carbon citrate a CoA group removed 2 CO2 is released from 6 carbon citrate 5 carbon molecule a H removed NAD NADH 3 5 carbon molecule oxidized and CO2 released again 4 carbon molecule a NADH and CO2 produced b 1 ATP produced 4 4 carbon molecule oxidized and regenerate 4 carbon molecule a H removed NAD FAD NADH and FADH2 c PRODUCTS 1 cycle 2 cycles 2 CO2 4 CO2 3 NADH H 6 NADH 2H 1 FADH2 2 FADH2 1 ATP 2 ATP 3 Electron Transport Chain oxidative phosphorylation Allows the release of large amount of energy stored in NADH and FADH2 a Occurs in inner membrane of mitochondria b Recycles NAD and FAD for Krebs Cycle and Transition Reaction c Allows electrons and H to be accepted by O2 to make water d Integral membrane proteins on inner membrane i ii iii iv Complex I Complex II Complex III Cytochrome c oxidase complex ATP Synthase 1 NADH oxidizes and donates electron to Complex I a H goes from matrix to intermembrane space b FADH2 skips Complex I and donates electron to CoQ 2 Electron carried by CoQ to Complex II a H goes from matrix to intermembrane space 3 Electron carried by Cyt c to Complex III a H goes from matrix to intermembrane space 4 O2 final electron acceptor takes electron from Complex III and forms H2O 5 High proton H concentration in intermembrane space creates potential energy to make ATP a H flow through ATP Synthase back into matrix down its concentration gradient b ADP phosphate ATP c PRODUCTS 34 ATPs 3 ATP per NADH 2 ATP per FADH2 Alternative Energy FATS Lipolysis to split lipids acids Triglycerides stored in adipose cells break into glycerol and fatty Glycerol PCAL for glycolysis Fatty acids beta oxidation acetyl groups 2 carbon acetyl coA for Krebs Cycle Lipogenesis to make new lipid from carbohydrates and amino acids Glycerol and fatty acids from PGAL and acetyl CoA form new triglycerides PGAL glycerol Acetyl coA fatty acids PROTEINS Excess proteins in diet cannot be stored like glycogen or fats must be broken down by body 1 Proteases break peptide bonds of proteins back to amino acids 2 Deaminases break amino group off into ammonia urea excreted in urine 3 Remaining amino acid rearranged in cells to enter cellular respiration as pyruvate acetyl CoA or right into Krebs Cycle
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