introduction, Oxidative phosphorilation, glycogen metabolism, fatty acid metabolism, glyclolysis, gluconeogenesis, pentose phosphate pathway, cholesterol metabolism, amino acid metabolism, lipoproteins
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| 450170327 | principles of metabolic pathways | irreversible, first committed step, regulated, occurs in specific cellular locations | 0 | |
| 450170328 | enzymes that control rate limiting steps are regulated by: | allosteric modulators, covalent modification, substrate concentration, enzyme concentration | 1 | |
| 450170329 | gibbs free energy at equilibrium | Zero | 2 | |
| 450170330 | coupling of reactions | by coupling an energetically unfavorable reaction with one that gives off extra energy | 3 | |
| 450170331 | energy charge has to do with: | ratios between ATP, ADP and AMP in the cell | 4 | |
| 450170332 | High energy charge = 1.0 | ATP | 5 | |
| 450170333 | Low energy charge = 0 | AMP | 6 | |
| 450170334 | High energy charge favors | anabolic reactions | 7 | |
| 450170335 | low energy charge favors | catabolic reactions | 8 | |
| 450170336 | hydrolysis of ATP | Releases energy | 9 | |
| 450170337 | ATP synthesis | oxidative phosphorilation, glycolysis, citric acid cycle | 10 | |
| 450170338 | enzyme complexes of respiratory chain | 4 enzyme complexes: I) NADH-Q reductase, II) succinate-Q reductase, III) cytochrome reductase, IV) Cytochrome oxidase | 11 | |
| 450170339 | mobile carries of respiratory chain | Q (ubiquinone), citochrome c | 12 | |
| 450170340 | enzyme complexes that pump protons | I, III, IV | 13 | |
| 450170341 | electron carriers in oxidative phosphorilation | NADH, FADH2 | 14 | |
| 450170342 | final electron acceptor | O2 | 15 | |
| 450170343 | electrons moving along electron transport chain | each complex is reduced as they accept an electron and oxidized as it passes electrons to the next complex | 16 | |
| 450170344 | proteins that channel electrons into the electron transport chain | succinate dehydrogenase, glycerol 3-phosphate dehydrogenase | 17 | |
| 450170345 | oxidative phosphorylation is controlled by: | availability of substrates: NADH, O2, ADP, and phosphate | 18 | |
| 450170346 | blocked NADH-Q reductase by amytal rotenone | Oxidative phosphorylation can still take place, because electrons can be fed into ubiquinone | 19 | |
| 450170347 | antimycin A blocks complex III | oxidative phosphorylation will be shut down because there is no other complex to accept electrons | 20 | |
| 450170348 | ATP synthase | Head place for ATP synthesis, pore proton channel | 21 | |
| 450170349 | Synthesis of ATP | as protons go through pore, catalytic sites change conformation, need 3 protons for each ATP formed | 22 | |
| 450170350 | Yield of ATP in oxidative phosphorylation | NADH = 2.5 ATP, FADH = 1.5 ATP; for each glucose = 30(32) ATP | 23 | |
| 450170351 | can NADH cross the mitochondrial membrane? | No | 24 | |
| 450170352 | transporter in muscle | Glycerol-3 phosphate shuttle | 25 | |
| 450170353 | transporter in liver and heart | malate-aspartate shuttle | 26 | |
| 450170354 | oligomycin | binds to ATPase and blocks proton channel | 27 | |
| 450170355 | uncouplers | disrupt the electrochemical gradient by the diffusion of protons across inner membrane, generating heat instead of producing ATP | 28 | |
| 450170356 | thermogenin | uncoupling protein in brown adipose tissue. | 29 | |
| 450170357 | thermogenin function | transports protons from cytosolic side of inner mitochondrial membrane back into the mitochondrial matrix without ATP generation, generating heat. | 30 | |
| 450387649 | glycogenin | dimer that initiates glycogen synthesis by catalyzing the attachment of glucose to a tyrosine residue on itself | 31 | |
| 450387650 | enzymes for synthesis of glycogen | glycogen synthase, branching enzyme | 32 | |
| 450387651 | glycogen synthase | UDP-Glucose used to add a glucose residue to main chain. a-1,4 linkage | 33 | |
| 450387652 | branching enzyme | breaks a-1,4 linkage and forms a-1,6 linkage. transfers 7 glucose residues at a time | 34 | |
| 450387653 | substrates for glycogen synthesis | UDP-glucose | 35 | |
| 450387654 | UDP-Glucose | used to add glucose to main glycogen chain | 36 | |
| 450387655 | enzymes used during glycogen degradation | glycogen phosphorylase, debranching enzyme (transferase, and a-1,6 glucosidase) | 37 | |
| 450387656 | glycogen phosphorylase | uses phosphate to break a-1,4 linkage and release glucose 1-phosphate. continues until 4 residues are left | 38 | |
| 450387657 | debranching enzyme | bifunctional enzyme, transferase and a-1,6 glucosidase | 39 | |
| 450387658 | transferase enzyme | transfers 3 glucose residues leaving single glucose linked via a-1,6 linkage | 40 | |
| 450387659 | a-1,6 glucosidase | release of the a-1,6 linked glucose as free glucose by hydrolysis reaction | 41 | |
| 450387660 | products of glycogen degradation | glucose 1-phosphate and free glucose | 42 | |
| 450387661 | t/f: glucose 6-phosphate can travel in blood | false. needs to be converted to free glucose by glucose 6-phosphatase found only in liver | 43 | |
| 450387662 | glycogen phosphorylase regulation | inactive when dephosphorylated, active when phosphorylated | 44 | |
| 450387663 | glycogen synthase regulation | inactive when phosphorylated, active when dephosphorylated | 45 | |
| 450387664 | glycogen degradation promoted by hormones | glucagon and epinephrine | 46 | |
| 450387665 | regulation of glycogen metabolism by glucagon and epinephrine | hormones bind to receptors and activate adenylate cyclase --> elevated cAMP activates protein kinase A (PKA) --> degradation of glycogen by activating phosphorylase and inhibition of glycogen synthesis by inhibiting synthase | 47 | |
| 450387666 | insuline promotes glycogen synthesis | activates PPI --> deactivates phosphorylase kinase & phosphorylase, and activates glycogen synthase | 48 | |
| 450387667 | where does the breakdown of glycogen to glucose occurs? | liver and muscle by phosphorolysis | 49 | |
| 450387668 | rate limiting step in fatty acid synthesis | acetyl coa --> malonyl coa | 50 | |
| 450387669 | enzyme in rate limiting step of fatty acid synthesis | acetyl coa carboxylase with cofactor biotin | 51 | |
| 450387670 | fatty acid synthesis characteristics | NADPH is the reductant, at the end two carbons are added, cytoplasm, intermediates linked to ACP, enzymes joined in single polypeptide chain (fatty acid synthase), require energy, regulation: acetyl coa carboxylase | 52 | |
| 450387671 | beta-oxidation characteristics | NAD and FAD are the oxidants, mitochondria, intermediates linked to coenzyme A, enzymes different polypeptides, yield energy, regulation: acetyl coa availability | 53 | |
| 450387672 | fatty acid synthesis process | condensation - reduction (NADPH) - dehydration - reduction (NADPH) | 54 | |
| 450387673 | acetyl coa carboxylase regulation | activated by: citrate, high insulin, induction (fed state) inactivated by: long fatty acid chains, low energy charge, induction (starvation state) | 55 | |
| 450387674 | beta-oxidation regulation | inhibition of carnitine acyl tranferase, availability of substrates, stimulation of adipose tissue lipases | 56 | |
| 450387675 | ketone bodies | produced from acetyl coa when fat breakdown predominates | 57 | |
| 450387676 | T/F: liver can use ketone bodies | false. because it lacks the enzyme beta-ketoacyl-CoA transferase | 58 | |
| 450387677 | beta hydroxybutyrate | ketone body that can be used by muscles and reform acetyl coa for metabolism by citric acid cycle | 59 | |
| 450430199 | glycolysis takes place in | cytosol | 60 | |
| 450430200 | rate limiting steps of glycolysis | hexokinase, PFK-1, pyruvate kinase | 61 | |
| 450430201 | hexokinase | glucose + ATP --> glucose 6-phosphate + ADP | 62 | |
| 450430202 | PFK-1 (Phosphofructokinase 1) | committed step // F6P + ATP --> F1,6BP + ADP | 63 | |
| 450430203 | pyruvate kinase | final step // phosphoenolpyruvate + ADP --> pyruvate +ATP | 64 | |
| 450430204 | Hexokinase regulation | inhibited by: glucose 6-phosphate | 65 | |
| 450430205 | PFK-1 regulation | activators: AMP, F2,6-BP inhibitors: ATP, citrate and H+ | 66 | |
| 450430206 | Pyruvate kinase regulation | activator: F1,6-BP inhibitors: ATP and alanine | 67 | |
| 450430207 | regulation in liver | high glucose -> inc F2,6BP -> inc glycolysis starvation -> dec F2,6BP -> inc gluconeogenesis | 68 | |
| 450430208 | overall function of glycolysis | to convert glucose into two molecules of pyruvate | 69 | |
| 450430209 | ATP and NADH produced during glycolysis | 4 ATP - 2 used, 2 NADH | 70 | |
| 450712001 | substrate level phosphorylation vs oxydative phosphorylation | SLP during glycolysis, refers to the phosphorylation of ADP to ATP independent of electron transport. ox ph is the process in which ATP is formed as a result of the transfer of electrons from NADH/FADH2 to O2 by a series of electrons carriers | 71 | |
| 450712002 | products produced during anaerobic conditions in glycolysis | lactate acid (humans, ethanol (non-humans) + energy | 72 | |
| 450712003 | products produced during aerobic conditions in glycolysis | CO2 + H2O + energy | 73 | |
| 450730514 | citric acid cycle substrates | can i keep selling sex for money, officer? citrate, isocitrate, alpha-ketoglutarate, succinyl-coa, succinate, fumarate, malate, oxaloacetate | 74 | |
| 450730515 | Citric acid cycle enzymes | so again david dances silly dances for diana citrate Synthase, Aconitase, isocitrate Dehydrogenase, alpha-ketoglutarate Dehydrogenase, succinyl-CoA Synthetase, succinate Dehydrogenase, Fumarase, malate Dehydrogenase | 75 | |
| 450748838 | key regulatory enzymes of citric acid cycle | citrate synthase, isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase | 76 | |
| 450766013 | citrate synthase regulation | inhibited by: citrate and ATP | 77 | |
| 450748840 | isocitrate dehydrogenase regulation | activated by: ADP inhibited by: ATP and NADH | 78 | |
| 450748841 | alpha-ketoglutarate dehydrogenase | inhibited by: succinyl coa, ATP, and NADH | 79 | |
| 450748839 | pyruvate dehydrogenase regulation | inhibited by acetyl coA, NADH, and ATP | 80 | |
| 450766014 | pyruvate dehydrogenase cofactors | thiamine phytophosphate, lipoamide, and FAD | 81 | |
| 450766015 | thiamine phytophosphate | oxidative decarboxylation of pyruvate | 82 | |
| 450766016 | lipoamide | transfers acetyl group to CoA | 83 | |
| 450766017 | FAD as cofactor for pyruvate dehydrogenase | regenerates oxidized lipoamide | 84 | |
| 450766018 | one round of citric acid cycle yields: | 1 GTP, 3NADH, 1 FADH2, 2 CO2 | 85 | |
| 450942535 | Gluconeogenesis | synthesis of glucose from non-carbohydrate precursors such as (aa) alanine, lactate and glycerol | 86 | |
| 450942536 | gluconeogenesis vs glycolysis | gluconeogenesis is not a direct reversal of glycolysis, but there are three reactions bypassed | 87 | |
| 450942537 | first bypass reaction of gluconeogenesis | pyruvate -pyruvate carboxylase-> OAA -PEP carboxykinase-> PEP | 88 | |
| 450942538 | pyruvate carboxylase cofactor | biotin | 89 | |
| 450942539 | allosteric activator of pyruvate carboxylase | acetyl coa. high acetyl coa signals need for OAA | 90 | |
| 450942540 | second bypass reaction of gluconeogenesis | F1,6-BP + H2O --F1,6-BPase-> F6-P + Pi | 91 | |
| 450942541 | third bypass reaction of gluconeogenesis | glucose 6-ph + H2O --glucose 6-phosphatase--> glucose + Pi | 92 | |
| 450942542 | transport of oxaloacetate out of mitochondria to the cytosol | since pyruvate carboxylase is the only enzyme of gluconeogenesis found in the mitochondria, OAA needs to be converted into malate (by NADH-linked malate dehydrogenase), exit the mitochondria via malate transporter and then be converted back to OAA by NAD-linked malate dehydrogenase in the cytosol | 93 | |
| 450942543 | cori cycle purpose | pyruvate and NADH accumulates in muscles during anaerobic glycolysis so lactate is produced. NAD+ is required for glycolysis to continue, so lactate is transported to liver, converted back to glucose and returned to muscles (check) | 94 | |
| 450957023 | pentose phosphate pathway | generates: - NADPH for fatty acid synthesis - ribose-5-ph for DNA, RNA and nucleotide synthesis - sugar phosphate intermediates for glycolytic and gluconeogenesis pathways | 95 | |
| 450957024 | branches of PPP: | Oxidative branch non-oxidative branch | 96 | |
| 450957025 | oxidative branch of PPP: | enzyme glucose 6-ph dehydrogenase converts: glucose 6-ph into ribulose 5-ph with the formation of 2 molecules of NADPH enzyme phosphopentose isomerase converts ribulose 5-ph into ribose 5-ph | 97 | |
| 450957026 | non oxidative branch of PPP: | Excess ribose-5-phosphate is converted to glycolytic intermediates glyceraldehyde-3-ph and fructose-6-ph enzymes: 2 transketolases & 1 transaldolase | 98 | |
| 450957027 | products of non-oxidative branch of PPP | can be used as intermediates to other pathways | 99 | |
| 451211951 | biosynthesis of cholesterol | cholesterol synthesized from acetyl coA | 100 | |
| 451211952 | rate limiting step in cholesterol biosynthesis | occurs in the ER, HMG-CoA reductase | 101 | |
| 451211953 | HMG-CoA Reductase regulation | synthesis of ketone bodies, - high levels of glucagon phosphorylates it and turns it off - high levels of insulin dephosphorylates it and activates it - inc [steroids] --> activation of proteolytic degradation of enzyme - mRNA level regulated by cholesterol level: low cholesterol inc mRNA; high cholesterol dec mRNA | 102 | |
| 451211954 | statins | inhibit cholesterol synthesis by competitive inhibition for the active site of HMG-CoA reductase | 103 | |
| 451211955 | synthesis of bile salts | - exclusively in liver RLS: cholesterol converted to 7alpha-hydroxycholesterol by 7alpha-hydroxylase. - uses NADPH - inhibited by bile salts | 104 | |
| 451211956 | steroid hormones derived from cholesterol | cholesterol is converted to pregnenolone - requires 3 NADPH and O2 | 105 | |
| 451211957 | pregnenolone | precursor of all steroids | 106 | |
| 451242489 | amino acid metabolism | proteins are broken down to AA - alpha-amino group is removed and excreted as urea - remaining c-skeleton used as precursor | 107 | |
| 451242490 | remaining c-skeleton from AA can be used as precursor for: | TCA cycle, gluconeogenesis, fatty acids and ketone bodies | 108 | |
| 451242491 | transamination: | removal of alpha-amino group - transfer alpha-amino group to alpha-ketoglutarate to form glutamate - glutamate + NAD + H2O forms ammonia (NH4) and NADH | 109 | |
| 451242492 | enzymes that transfer alpha-amino group fom AA to form alpha-keto acid | transaminases - aspartate transaminase - alanine transaminase | 110 | |
| 451264877 | NH2 transported to liver for excretion by | alanine and glutamate | 111 | |
| 451242493 | rate limiting step of urea cycle | formation of carbamoyl phosphate by carbamoyl phosphate synthethase 1 | 112 | |
| 451242494 | regulation of rate limiting step of urea cycle | carbamoyl phosphate synthethase 1 - requires 2 ATP, so ATP (+), ADP (-) - increased ([S]) (+) - allosteric: N-acetylglutamate (NAG) (+) | 113 | |
| 451264878 | Lesch-Nyhan disease | X-linked, almost always men, compulsive, aggressive, self-mutilating behavior, elevated PRPP ->excess purines -> excess uric acid = gout + neuro symptoms | 114 | |
| 451264879 | Lipoproteins transportation | transport fatty acids from the intestine to the peripheral tissues and to the liver | 115 | |
| 451264880 | VLDL transportation | transport fatty acids from the liver to the surrounding tissues | 116 | |
| 451264881 | apoproteins are recognized by | LDL receptors during endocytosis | 117 |
