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BMB 401 Exam 3 Study Guide With
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Products of TCA - ANSWER 1 ATP, 3 NADH, 1 FADH2, 2 CO citrate synthase - ANSWER The condensation of acetyl CoA and oxaloacetate to form citrate citrate synthase regulation - ANSWER negative: ATP, NADH, succinyl CoA aconitase - ANSWER isomerization in two runs: dehydration and rehydration citrate to isocitrate planes relative to aconitase - ANSWER citrate is symmetrical, isocitrate is asymmetrical isocitrate dehydrogenase - ANSWER 2 rxns: oxidation plus decarboxylation isocitrate to alpha-ketoglutarate
- produces CO2 and NADH Isocitrate dehydrogenase regulation - ANSWER rate limiting step positive: ADP, NAD+ negative: NADH, ATP cofactors of alpha-ketoglutarate dehydrogenase - ANSWER TPP, Lipoamide, FAD, NAD+, coA products of alpha-ketoglutarate dehydrogenase - ANSWER succincyl coA,
NADH, CO
alpha-ketoglutarate dehydrogenase - ANSWER alpha-ketoglutarate to succinyl-CoA alpha-ketoglutarate dehydrogenase regulation - ANSWER positive: AMP negative: succinyl coA, NADH, ATP Succinyl CoA synthetase - ANSWER substrate level phosphorylation succinyl coA to succinate production of GTP and release of coA succinate dehydrogenase - ANSWER succinate to fumarate succinate dehydrogenase regulation - ANSWER negative: FADH2/FAD succinate dehydrogenase facts - ANSWER - flavin ring covalently attached
- imbedded in the inner mitochondrial membrane
- also part of the ETC fumarase - ANSWER fumarate to malate malate dehydrogenase - ANSWER malate to oxaloacetate NAD+ is cofactor malate dehydrogenase regulation - ANSWER negative: NADH/NAD+ anaplerotic reactions - ANSWER replenishs intermediates in the TCA cycle pyruvate carboxylase - ANSWER pyruvate + HCO3- + ATP --> oxaloacetate + ADP + Pi
glycerol 3-phosphate shuttle - ANSWER 1. reduction of DHAP to glycerol 3-P
- reduction of FAD to FADH
- reduction of MT electron carrier Q to form QH Q/QH2 - ANSWER mobile carrier of electrons in the inner mitochondrial membrane Q/QH2 reduction/oxidation - ANSWER Q- ubiquinione (oxidized) QH2- ubiquinol (reduced) malate-aspartate shuttle - ANSWER don't want a lot of oxaloacetate, so move out of matrix by becoming aspartate which can leave; then convert back to glutamate cytoplasmic glycerol 3-phosphate dehydrogenase - ANSWER DHAP to glycerol 3 phosphate mitochondrial glycerol 3 phosphate dehydrogenase - ANSWER glycerol 3 phosphate to DHAP malate dehydrogenase - ANSWER malate to oxaloacetate aspartate amino transferase - ANSWER transfers aspartate and oxaloacetate; glutamate and alpha-ketoglutarate pyruvate - Oxaloacetate alpha-ketoglutarate - alanine -
aspartate - glutamate - NADH transfer pontential - ANSWER higher electron transfer potential than water so it is more likely to donate electrons reducing equivalents NADH/FADH2 - ANSWER glycolysis, PDC, TCA cycle, Fattly acid catabolism energy difference in ETC - ANSWER used to pump protons from the matrix to the membrane flow through ETC - ANSWER flow down concentration; releases protons through mitochondrial membrane; goes through ATP synthase to generate ATP order of ETC - ANSWER NADH-> Complex 1-> coenzyme Q(complex 2 and glycerol shuttle 3p) -> complex 3 -> cytochrome c-> complex 4 -> 1/2 O Q - ANSWER within membrane; shuttles electrons from I and II and glycerol 3-p to III C - ANSWER attached to III; transfers electrons from III to IV IV - ANSWER oxygen bound; passes electrons to oxygen to yield water ubiquinone - ANSWER picks up electrons 1 at a time to make ubiquinol ubiquinol - ANSWER carries e- from complexes 1 and 2 from glycerol 3-P shuttle to 3- protons from matrix to inner membrane space to be passed to C complex 4 unusual - ANSWER contain copper ions how oxygen is held - ANSWER as a peroxide bridge between an iron and
open - ANSWER nucleotide exchange - ATP leaves, ADP and Pi enter loose - ANSWER holding pattern tense - ANSWER residues in beta subunit come together to make ATP Thermogenin (uncoupling protein-1) - ANSWER inserts into IM membrane that allows protons to be transported through this inner membrane into the matrix non shivering thermogenesis found in brown fat - decreases with age
thermogenin and DNP - ANSWER uncouple the oxidative part from the phosphorylation part
rotenone - ANSWER insecticide- complex 1
amytal - ANSWER barbiturate - complex 1
anitmycin - ANSWER antibiotic - complex 3
Cyanide, Azide, H2S, CO - ANSWER complex 4
oligomycin - ANSWER antibiotic
inhibits ATP synthase
products of ATP synthase - ANSWER 1 ATP per 1/2 O 2.5 ATP per NADH 1.5 ATP per FADH
glycogen - ANSWER highly branched polymer of glucose
straight chains - ANSWER alpha 1,4 linkages
branched points - ANSWER alpha 1,6 linkages
glycogen storage - ANSWER stored as granules in cytoplasm; muscle - more total liver- higher concentration
glycogenin - ANSWER initiator primer molecule has directionality- reducing ends are attached to glycogenic; non reducing are at ends of branches
Phosphoglucomutase in muscle - ANSWER phosphate keeps glucose in the cell for the muscle's own energy needs
phosphoglucomutase in liver and kidney - ANSWER phosphate removed from c-6 by glucose-6P; function during gluconeogenesis and found in the ER; free glucose released
problem with branch points - ANSWER glycogen phosphorylase cannot catalyze the breakdown of alpha 1,6 - so need two other enzymes
deb ranching enzyme - ANSWER transferase and alpha 1,6 glucosidase
transferase - ANSWER takes 3 glucose and moves to the end of the straight chain
alpha 1,6 glycosidase - ANSWER hydrolyze glucose off to remove branch point
hexokinase - ANSWER in the muscles phosphorylates the free glucose so it does not leave
UDP-glucose pyrophosphorylase - ANSWER activates glucose
glucose 1-P + UTP to UDP glucose
glycogen synthase - ANSWER adding activated glucose
glycogen phosphorylase - ANSWER primary site of regulation
glycogen phosphorylase regulation - ANSWER tense state - less active b relaxed state - more active - a when not phosphorylated - b
phosphorylase kinase - ANSWER phosphorylates to turn b into a
phosphorylase kinase regulation - ANSWER global: phosphorylation by PKA local: increase in intracellular Ca++
epinephrine - ANSWER adrenal medulla secreted when hungry, upset or angry flight or fight
glucagon - ANSWER pancreas
binds to receptor causing dimerization of receptor which activates protein phosphate 1 and glycogen kinase to inactive that
Phases of the pentose phosphate pathway - ANSWER oxidative and non-oxidative
oxidative - ANSWER NADPH production
non-oxidative - ANSWER inter-conversion of sugars
products of PPP - ANSWER -NADPH for reductions -Ribose for nucleotide synthesis -Glycolytic intermediates
NAD+ - ANSWER - cellular NADH/NAD+ ratios favor NAD+
- NAD+ oxidizes substrates in catabolic pathways
- NADH powers ATP synthesis
NADP+ - ANSWER - cellular NADPH/NADP+ favor NADPH
- NADPH reduces substrates in reductive synthetic reactions in anabolic pathways
mitochondrial matrix - ANSWER - NAD+ oxidizes substrates to produce reducing equivalents: NADH from citric acid cycle, FA oxidation
- NADH reduces electron carriers to power ATP synthase
- ETC
cytoplasm - ANSWER NADPH reduces substrates in reductive synthetic reactions:
- FA synthesis
- cholesterol synthesis -nucleotide synthesis
- neurotransmitter synthesis
other NADH purposes - ANSWER - reducing equivalents for biosynthesis
- combats infection by synthesizing superoxide to kill microbes and nitric oxide to kill bacteria
- reduces and reactivates glutathione
glutathione reduced state - ANSWER protects against oxidative stress - RBC are particularly sensitive
ribulose 5-phosphate
phosphopentose isomerase - ANSWER ribulose-5-phosphate to ribose-5-phosphate
phosphopentose epimerase - ANSWER ribulose-5-phosphate to xylulose-5-phosphate
non oxidative PPP rxn 1 - ANSWER transketolase C5+C5 to C3 and C
rxn 2 - ANSWER transaldolase c3 and c7 to c6 and c
reaction 3 - ANSWER transketolase c4 and c5 to c6 and c
need high ribose - ANSWER run non Oppp backwards
NADPH and ribose - ANSWER use OPPP forward
need high NADPH - ANSWER OPPP nonOPPP - run products through gluconeogenesis
need NADPH and ATP - ANSWER OPPP non OPPP- products are sent though glycolysis
regulation of PPP - ANSWER G6-p dehydrogenase is irreversible and rate limiting
- regulated by NADP+/NADPH levels: low levels are slow runs
- NADP+ is necessary for redox
- NADPH is a competitive inhibitor
Deficiency of glucose 6-phosphate dehydrogenase - ANSWER - most common enzyme deficiency
- x linked: most common in males
- usually subclinical
- increased susceptibility to oxidative injury
deficiency hemolytic anemia - ANSWER premature rupturing of RBC b/c the are unable to maintain their integrity (cannot stay in the reduced state)
oxidative challenge - ANSWER oxidative drugs - some antibiotics, antimalarials, fever reducers
ways of numbering FA - ANSWER 1) numbering from the carboxylate end
- laurate - ANSWER C 2) numbering from the methyl end, called the omega end
- myristate - ANSWER C
- palmitate - ANSWER C
- Sterate - ANSWER C
- arachidate - ANSWER C
- behenate - ANSWER C
- lignocerate - ANSWER C
- palmioleate - ANSWER C16:1 cis delta
- oleate - ANSWER C18:1 cis delta
linoleate - ANSWER C18:2 cis, cis delta 9,
linolenate - ANSWER C18:3 cis, cis, cis delta 9,12,
archidonate - ANSWER C20:4 all cis delta 5,8,11,
odd number branched chain FA - ANSWER uncommon in animals, common in bacteria
triacylglycerol - ANSWER three fatty acids linked to one glycerol molecule preferred fuel for liver, heart; skeletal muscle also uses
why triacylglycerols used for storage? - ANSWER yields greater quantity of ATP per gram then glycogen:
- highly reduced hydrocarbon FAs
- hydrophobic - no hydration shell mainly stored as fat and muscle
emulsification - ANSWER break up into smaller drops that are easier to suspend in aqueous solution
