Biochemistry: PATHWAYS Flashcards
Oxidative phosphorylation needs what 2 requirements?
mitochondria, oxygen
FADH:
what complex?
yields how many ATP?
complex 2
1.5ATP
NADH:
what complex?
yields how many ATP?
complex 1
2.5ATP
inhibitors of complex 1 (ETC)
B - barbiturates
A - amytal
R - rotenone
P - piericidin A
inhibitors of complex 2 (ETC)
M - malonate
T - TTFA
C - carboxin
inhibitors of complex 3 (ETC)
3AD
A - antimycin A
D - dimercaprol
inhibitors of complex 4 (ETC)
4 CCoSaH Cyanide Carbon monoxide Sodium azide Hydrogen sulfide
inhibitor of complex 5
oligomycin
inhibits the transport of ADP into and ATP out the mitochondria
atractyloside
examples of uncouplers
BAD
Brown fat
Aspirin
2,4, Dinitrophenol
insulin mediated transporter?
GLUT 4
GLUT 3 involves what organs?
BPK
brain
placenta
kidney
GLUT 2 vs GLUT 5
Glut 2 - K PLS kidney pancreas liver small intestine - basement membrane
glut 5 - SI - lumen
GLUT 1?
BPK + CR
brain, placenta, kidney
+
colon, RBCs
GLYCOLYSIS purpose? location? substrate? product/s? rate limiting?
- glucose metabolism for energy
- cytosol
- glucose –> 2 mol of pyruvate or lactate
**PFK-1
fructose 6,p –> fructose 1,6bisphosphate
hexokinase vs glucokinase?
present in ..?
inhibited by..?
Km/ vmax?
Hexokinase: most tissues
- glucose 6-p, low Km, low Vmax
glucokinase: liver, pancreas
- fructose 6-p, high Km, high Vmax
ATP yield of glycolysis?
aerobic & anerobic
aerobic - 5 or 7
anaerobic - 2
pyruvate has 4 fates? NAME ALL including the enzymes
- ) lactate (lactate dehydrogenase)
- ) pyruvate (p. dehydrogenase)
- ) oxaloacetate (p. carboxylase)
- ) ethanol (p. decarboxylase)
carboxylases need what co-factor?
biotin
dehydrogenases need what cofactors
1,2,3,L,5 b1, b2 b3, b5 (coenzyme A - pantothenic Acid) lipoic acid
Citric Acid Cylce purpose? location? substrate? product/s? rate limiting?
- formation of ATP; final common pathway
- mitochondria, except succinate dehydrogenase
- acetyl coa –> 2 C02, 1 GTP, 3 NADH, 1 FADh2
**isocitrate dehydrogenase
isocitrate –> a-ketoglutarate
ATP yield for TCA
10 ATP
complete oxidation of glucose will yield how many ATP?
30 or 32 ATPs
GLUCONEOGENESIS purpose? location? substrate? product/s? rate limiting?
- glucose formation
- liver 90%, kidney 10%
- both
- intermediates of glycolysis, TCA; TAG; lactate; carbon skeletons of glucogenic AA –> glucose
**fructose 1, 6-bisphosphatase
fructose 1,6 bisphosphate –> fructose 6,p
GLYCOGENESIS purpose? location? substrate? product/s? rate limiting?
- glycogen synthesis
- liver and muscle, cytosol
- a-d-glucose –> glycogen
**glycogen synthase
elongation of glycogen chains
GLYCOGENOLYSIS purpose? location? substrate? product/s? rate limiting?
- glycogen breakdown
- liver and muscle, cytosol
- glycogen –> glucose (liver), glucose 6-phosphate (muscle)
**glycogen phosphorylase
shortening of glycogen chains
fructose can be found in what organs
FOLS FRUCTOSE in Ovaries Liver Seminal vesicles
PPP/ HMP SHUNT purpose? location? substrate? product/s? rate limiting?
- produce NADPH, ribose 5-phosphate
- cytosol
- glucose 6-p –> NADPH, ribose 5-p
**Glucose 6-p dehydrogenase
glucose 6-p –> 6-phosphogluconate
predominant FA in coconut oil?
lauric acid 12:0
predominant FA in olive oil
oleic acid 18:1 (9)
essential FA
linoleic acid 18:2 (9,12)
linolenic acid 18:3 (9,12,15)
palmitic acid structure
16:0
20:4?
arachidonic acid
- precursor of prostaglandins
- derived from linoleic acid
LIPOGENESIS purpose? location? substrate? product/s? rate limiting?
- synthesis of FA
- cytosol
- acetyl Coa –> palmitoyl CoA
**acetyl CoA carboxylase
acetyl coa + hc03 + ATP –> malonyl Coa
shuttle used for lipogenesis?
for B - oxidation?
- CITRATE SHUTTLE
- CARNITINE SHUTTLE
BETA OXIDATION purpose? location? substrate? product/s? rate limiting?
- removal of acetyl coa, yielding NADH and FADH2
- muscle and liver, mitochondria
- palmitate –> 8 acetyl coa, 7 NADH, 7 FADH2
** carnitine palmitoyl transferase
ATP Yield of palmitate?
108 - 2 =
106 atps
KETOGENESIS purpose? location? substrate? product/s? rate limiting?
- synthesis of ketone bodies as alternative fuel
- liver mitochondria
- acetly coa –> AHA (acetone, b- Hydrodxybutarate acetoacetate)
**HMG-coA synthase
acetoacetyl coa + acetly coa –> hmg coa
CHOLESTEROL SYNTHESIS
location?
substrate?
rate limiting?
- cytosol
- acetly coa
**HMG-coA reductase
Hmg coa –> mevalonate
UREA CYCLE purpose? location? substrate? product/s? rate limiting? allosteric factor?
- convert nitrogenous waste (ammonia) to urea
- liver, both
- CO2, Aspartate, NH3 –> urea
**Carbamoyl phosphate synthetase 1
NH3 + C02 –> carbamoyl phosphate
allosteric factor: n-acetylglutamate
transamination of alanine will yield?
pyruvate
transamination of oxaloacetate will yield?
aspartate
transamination of glutamate will yield?
a-ketoglutarate
HEME SYNTHESIS
location?
rate limiting?
co factor?
- mitochondria & cytosol
**ala synthase
glycine + succinyl coa –> d ALA
co factor: b6
phase that is OXIDATIVE & IRREVERSIBLE?
what enzyme involved? cofactor?
product
PHASE 1
g6p dehydrogenase (no cofactor)
NADPH
phase that is NONOXIDATIVE & REVERSIBLE?
what enzyme involved? cofactor?
product
PHASE 2
transketolase (+ thiamine)
ribose 5-phosphate
2 pathways involved in substrate level phosphorylation?
- ) glycolysis
2. ) TCA - succinate thiokinase step
ROS?
- superoxide
- hydrogen peroxide
- hydroxyl radical
second messenger of glucagon? insulin?
glucagon - cAMP
insulin - tyrosine kinase
pathways that occurs in both the cytosol and mitochondria?
HUG
H - HEME SYNTHESIS
U - UREA CYCLE
G - GLUCONEOGENESIS
shuttle for glycolysis? will yield how many ATP per molecule?
MALATE ASPARTATE SHUTTLE - 2.5 ATP
GLYCEROPHOSPHATE SHUTTLE - 1.5 ATP
most common enyzme defect in glycolysis?
pyruvate kinase
- hemolytic Anemia
most common cause of congenital lactic acidosis
pyruvate dehydrogenase
- x-linked
- treat with ketogenic diet
the enzyme inhibited by fluoroactate
: TCA cycle
aconitase
the enzyme inhibited by arsenite and ammonia
: TCA cycle
a-ketoglutarate dehydrogenase
pathways that occur in the mitochondria
BATOK B - B - OXIDATION A - ACETYL COA PRODUCTION T - TCA CYCLE O - OXIDATIVE PHOSPHORYLATION K - KETOGENESIS
the rate limiting step of glycogenolysis requires what co-factor?
what is the rate limiting step?
- B6
- glycogen phosphorylase
sequence of steps by lipogenesis?
will yield what?
CODE RED RED condensation, reduction, dehydration, reduction - 1 acetyl coa - 7 malonyl coa - 7 carbon out - 14 nadph needed
sequence of steps by b-oxidation?
will yield what?
OHOT oxidation, hydration, oxidation, thiolysis - 8 acetly coa - 7 nadh - 7 fadh
what is the difference between carnitine palmitoyl transferase 1 & 2 deficiency?
CPT 1 - affects liver
CPT 2 - affects cardiac and skeletal muscle
rate limiting step for steroid synthesis
desmolase
what are glucogenic substances?
ECG
epinephrine
cortisol
growth hormone
rate limiting step of purine synthesis
PRPP glutamyl amidotransferase
rate limiting step of pyramdine synthesis
carbamoyl phosphate synthetase 2
what is the parent molecule for purine?
pyramidine?
purine - IMP (inosine monophosphate)
pyramidine - UMP (orotdine monophosphate)
what is the sequence of formation of purine and pyramdine: which comes first? the sugar or ring
sugar first - purine
ring first - pyramidine
purine or pyramidine?
- associated with gout
purine
purine or pyramidine?
- associated with salvage pathway
purine
purine or pyramidine?
- degradation products:
b-alanin (precursor of acetyl coa) &
b-aminoisobutyrate (precursor of succinyl coa)
pyramidine
purine or pyramidine?
- ring cannot be cleaved in human cells
purine
purine or pyramidine?
- ring can be degraded to water soluble products
pyramidine
purine or pyramidine?
- degradation products: uric acid
purine
purine or pyramidine?
- associated with orotic aciduria
pyramidine
what AB drug INHIBITS
DIHYDROPTEROATE SYNTHASE
SULFONAMIDES
what chemotherapeutic drug INHIBITS
THYMIDYLATE SYNTHASE
5-FU
what 2 drugs (chemotherapuetic & AB) INHIBITS
DIHYDROFOLATE REDUCTASE
METHOTHREXATE
TRIMETHOPRIM
what drug INHIBITS
HYPOXANTHINE OXIDASE
ALLOPURINOL
what chemotherapeutic drug INHIBITS
IMP DEHYDROGENASE
MYCOPHENOLATE
rate limiting step for bile synthesis
7a-hydroxylase