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Quiz 8 Flashcards

1
Q

what way can THF ox/red reactions go

A

methylene can go to methenyl OR methyl

methyl CANNOT be oxidized further

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2
Q

what AA can react with THF

A

serine+THF glycine + 3

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3
Q

what is the glutamic acid reaction

A

glutamate + NAD alphaKG + NADH+ NH3

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4
Q

how is glutamine produced

A

glutamate + NH3 + ATP –> Glutamine + ADP + Pi

*THIS is how we get ammonia from other cells to liver to it can undergo urea cycle

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5
Q

how is aspartate produced

A

transamination:

OAA –> Aspartate
Glutamate –> alphaKG

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6
Q

how is asparagine produced

A

Aspartate + glutamine + ATP –> Asparagine + glutamate + ADP + Pi

*GLUTAMATE can give aspartate and glutamine which can give asparagine

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7
Q

how is alanine produced

A

Amino transferase reaction

Pyruvate –> Alanine
Glutamate –> alphaKG

*exercising muscle is using a lot of glucose so lots of pyruvate being produced and exceeding capacity of PDH and LDH reactions. XS pyruvate converted to alanine, leaves muscle, goes to liver and gets converted back to pyruvate where it can undergo gluconeogenesis and then glucose can go back to muscle

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8
Q

what is the AA that cycles with gluc in exercising muscle

A

ALANINE. exercising muscle is using a lot of glucose so lots of pyruvate being produced and exceeding capacity of PDH and LDH reactions. XS pyruvate converted to alanine, leaves muscle, goes to liver and gets converted back to pyruvate where it can undergo gluconeogenesis and then glucose can go back to muscle

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9
Q

how is proline produced

A

glutamate –> gamma Glutamic semialdehyde –> ornithine and proline

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10
Q

what is ornithine produced from and what can it become

A

glutamate –> gamma glutamic semialdehude –> ornithine –> arginine (needs aspartate)

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11
Q

is arginine essential?

A

in adults, glutamate pathway is enough but in children it isnt so it is considered an essential AA

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12
Q

how is cysteine formed

A

methionine –> SAM –> SAH –> homocysteine + serine –> cysteine

*non essential as long as we have methionine and serine

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13
Q

how is tyrosine produced

A

phenylalanine –> tyrosine

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14
Q

how is serine produced

A

either from 3PGA in glycolysis or from reverse of folic acid reaction

glycine + THF –> serine (REVERSIBLE!)

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15
Q

how is glycine produced

A

glycine + THF –> Serine + methyleneN5N10THF

OR

de novo from CO2 + ammonia + methylene THF

(methylene can come from histidine or another serine)

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16
Q

what are catecholamines

A

DOPA, dopamine, norepi, epi

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17
Q

where are catecholamines synthesized

A

in brain as adrenals, function as neurotransmitters and regulators of blood flow, BP, metabolism, and E production

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18
Q

what is parkinsons caused by

A

deficiency in dopaminergic neurons in substantia nigra of brain. tx with DOPA which can cross BBB, while dopamine cannot

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19
Q

catecholamine path

A

tyrosine –> DOPA + DHB + H2O–>Dopamine –> Norepi –> Epi

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20
Q

dopa to dopamine

A

dopa decarboxilase with PLP (loses CO2)

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21
Q

dopamine to norepi

A

OH in, cofactor is vit C

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22
Q

norepi to epi

A

SAM, CH3 is put on

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23
Q

tyrosine to DOPA + DHB + H20

A

tyrosine hydroxylase, THB + O2

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24
Q

what is GSH produced from

A

3 Amino Acids (glutamate, cysteine, glycine)

Glutamate + cysteine + ATP –> glu-cys + glycine + ATP –> GSH

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25
what can tryptophan produce (not in brain)
acetyl coA/NH4/CO2 via tryptophan deoxygenase NOTE: some metabolites can produce NAD and NADP
26
what is pellagra caused by
deficiency in tryptophan
27
what does tryptophan metabolize to in the brain
5 hydroxytryptophan --> serotonin (neurotransmitter, vasoconstrictor, important for blood pressure) --> melatonin
28
how does serotonin become melatonin
SAM becomes SAH
29
how does 5HT become serotonin
decarbox with PLP as cofactor
30
how is creatine produced
glycine + arginine --> guanidoacetate + ornithine --> creatine
31
what can creatine produce
creatine +ATP --> creatine phosphate --> creatinine
32
what is important about creatine phosphate reaction
reversible so it can produce ATP, one of the ways that our body stores ATP for muscle and brain. different isoforms in diff tissues so can be diagnostic for heart attack, stroke, etc
33
decarbox of glutamate gives
GABA - inhibitory neurotransmitter (PLP cofactor)
34
decarbox of histidine gives
histamine - vasodilator, allergic rxns, protein digestion (PLP cofactor)
35
decarbox of serine
ethanolamine (base in phospholipid phosphatidyl ethanolimine) PLP cofactor
36
decarbox of ornithine
putrescine (precursor to DNA binding polyamine spermine) PLP cofactor
37
how is nitric oxide produced
ariginine + oxygen --> nitric oxide
38
what is function of nitric oxide
vasodilator, regulates BP, prevents platelet aggregation. given after heart attacks
39
nitric oxide and bacteria
reacts with heme enzymes to block oxygen activation but also affects mammalian anzymes
40
what can aginine become
citrulline, ornithine, nitric oxide
41
what is heme important for
carrier for oxygen carrier proteins (hb), electron transfer enzymes (mito cytochomes), cyt p450 for drug metabolism
42
where is heme synthesized
mainly in liver and erythropoetic tissues but all do some. (initially in mito and then goes out to cytosol)
43
shape of heme
ring shaped with iron in the center
44
how is heme synthesized
1. succinyl coA + glycine --> delta ALA - leaves matrix 2. 2 ALA condense --> PBG 3. PBG x 4 --> uroporphyrinogen III which decarboxylates to give coprophorinogen which decarboxylates to give protophorinogen (BACK TO MITO!) 4. Protophyrinogen 9 oxidized to Protophyrin 5. Protophyrin with ferrochelatase gives Heme
45
what steps of heme synthesis are inhibited by lead
1. ALA dehydratase when two ALA condense to give PBG | 2. Ferrochelatase with protophyrin becomes Heme
46
what is the RL step of heme synthesis
succinyl coA + glycine --> ALA (IN MATRIX!)
47
how is iron in blood carrier, how is iron in blood stored
carried as apotransferrin, stored as ferritin
48
what function does ferritin have
antioxidant, binds iron so it cant undergo fenton reaction
49
what are prophyrias
deficiencies in each of the enzymes in heme biosynthetic pathway result in accumulation of porphyrin substrates. MANY double bonds can be oxidized by ROS singlet O2
50
heme breakdown time
RBCs Hb every 120 days, cytochromes 10-20 days
51
heme breakdown pathway
heme --> bilverdin + CO --> bilirubin --> bilirubin albumin --> bilirubindiglucorinide (conjugated) --> bile --> urobilinogin (urine) and stercobilin
52
what causes jaundice
accumulation of bilirubin - can be caused by lack of conjugation enzymes or blockage of bile duct *conjugated bilirubin excreted in bile
53
where in the heme breakdown pathway does it enter liver
bilirubin --> bilirubin albumin step
54
how is IMP synthesized
Ribose 5P from PPP ---> PRPP PRPP + glutamine ---> 5 ribosyl 1 amine + glutamate *catalyzed by amido phosphoribosyl transferase THIS turns into IMP
55
what does IMP become
IMP + GTP + aspartate --> adenylosuccinate --> adenylate (AMP) IMP + NAD --> xanthyalate ---> Guanylate (gluatmine gives amino, becomes glutamate)
56
purine salvage pathway
RNA constantly being degraded - can be excreted as uric acid or salvaged 1. Adenine phosphoribosyl transferase catalyzes: Adenine + PRPP --> AMP 2. Hypoxanthine guanine phosphoribosyl transferase catalyzes: hypoxanthine + PRPP ---> IMP guanine + PRPP --> GMP
57
what is lesch nyhan syndrom caused by
absence of hypoxanthine guanine phosphoribosyl transferase ... makes IMP so can reproduce AMP and GMP
58
purine breakdown
GMP -- guanosine -- guanine -- XANTHINE AMP -- IMP -- inosine -- hypoxanthine -- XANTHINE xanthine ultimately gets oxidized to uric acid which gets excreted
59
gout
XS uric acid forms - can inhibit xanthine oxidase (and therefore uric acid) with allopurinol *colchicine and methotrexate block inflammatory reaction which is activated in response to high uric acid
60
how is UMP synthesized
glutamine + CO2 + 2 ATP ---> carbamoyl phosphate --> orotic acid --> UMP
61
what is carbamoyl phosphate synthase used in
urea cycle and synthesis of pyrimidines
62
what is aspartates function in pyrimidine synthesis
reacts with carbamoyl phosphate to make orotic acid
63
what could high levels of orotic acid be caused by
decreased ornithine transcarbamylase in urea cycle so carbamoyl phosphate enters into pyrimidine synthesis pathway
64
how do you get from RNA to DNA
ribonucleotide diphosphate reacts with NADPH catalyzed by RR to give deoxyribonucleotide diphosphate
65
steps in RR
1. ATP binds active site, signals to synthesize pyrimidines 2. dCMP and dUMP formed, eventually dTTP formed. 3. dTTP in binding site signals purines to be synthesized 4. dGMP synthesized, eventually triggers dAMP which converts to dATP 5. dATP in activity site shuts down enzyme
66
sites on RR
1. active site where catalysis takes place, has thiol sites 2. activity site 3. substrate specificity site
67
SCIDS
due to deficiency of adenosine deaminsae, important in degradation of ATP to dATP to hypoxanthine and xanthine, get low b and T cells and low immune response
68
what would a test of high orotic acid in a newborn suggest
urea cycle deficiency
69
what does thioredoxin do
supplies necessary electrons to RR. in this process it gets oxidized, gets reduced back by thioredoxin reductase which gets its electrons via FADH2
70
glucogenic AA
produce pyruvate or any TCA cycle intermediate. All except leucine and somewhat lysine
71
ketogenic AA
produce Acetyl coA or acetoacetate. Leucine, Lysine, Isoleucine, Tryptophan, Phenylalanine, Tyrosine
72
C3 Family
5 OF THEM ``` Tryptophan Alanine Glycine Serine Cysteine ``` ALL GO TO PYRUVATE "Try to get AL to take GLYstening SERiously for his CYS"
73
C4 family
2 OF THEM Asparagine and aspartate *Aspartate removed to OAA into cycle
74
C5 family
5 OF THEM ``` Histidine Proline Arginine Glutamine Glutamate ``` ALL GET TRANSFERRED TO alpha KG HIS PROblems ARe that his is too GLUttonous (x2)
75
succinyl coA via AA
Valine Isoleucine Threonine Methionine All go to succinyl CoA VAL IS only THREe and does METh which SUCks rxn: methionine - homocysteine - alphaKB- propionyl coA - methylmalonyl coA - succinyl coA
76
branched AA breakdown
valine, isoleucine, leucine transamination to alpha keto acid, oxidative decarboxylation to produce CO2 and acyle coA product
77
leucine breakdown
acyl coA from leucine only to acetyl coA and acetoacetate, ONLY KETOGENIC
78
valine and isoleucine breakdown
goes to propionyl coA to methylmalonyl coA to succinyl coA so GLUCOGENIC isoleucine can also produce acetyl coA so also ketogenic
79
maple syrup urine disease
acyl coA dehydrogenase doesnt work so get build up of alpha keto acids which make urine smell like maple syrup
80
what happens to phenylalanine during breakdown
turns into tyrosine + DHB which can turn into fumarate or acetoacetate -- ketogenic and glucogenic
81
what happens if you are mussing phenylalanine hydroxylase
phenylketonuria because phenylalanine accumulates and enters other side pathways it normally wouldnt enter
82
what could cause black urine
tyrosine metabolism issue - accumulation of homogenestic acid which usually goes to fumarate
83
what are ways we can treat inborn errors of metabolism
- Restrict substrate - Provide cofactors - Provide product - Replace enzyme - Provide alternate routes of elimination - Treat secondary effects
84
PKU
Phenylketonuria - happens when there is a backup of phenylalanine because it cant become tyrosine --> dopamine --> melanin
85
what is the enzyme affected in PKU
phenylalanine hydroxylase with cofactor of tetrahydrobiopterin
86
how to treat PKU
restrict substrate -- diet with no phenylalanine. ADD tyrosine * Can also give cofactor now * can also replace enzyme now -- clinical trials underway right now
87
outcome of treated PKU
PKU used to only be treated for 6 years of life - now have treatment for life
88
maternal PKU outcome
microcephaly, congenital heart disease, craniofacial abnormalities, small for gestational age
89
cofactor metabolism in PKU
tetrahydrobiopterin deficiency. Increased phenylalanine, decreased dopamine and serotonin because also involved in tyrosin and tryptophan metabolism
90
malignant PKU
when there is an issue with the cofactor. cant metabolize phenylalanine, tyrosine, OR tryptophan
91
organic acidemia
inborn error where pathway intermediate that is elevated is a non amino organic acid (no NH3)
92
organic acidemia labs
HIGH plasma ammonia severe metabolic acidosis acid metabolites in urine
93
metabolism of propionyl coA
propionyl coA carboxylase turns it into methylmalonyl coA. without this enzyme get back up! *BIOTIN is cofactor
94
treatment of propionic acidemia
restrict substrate - VOMIT free formula VOMIT = Valine, OCFA, methionine, isoleucine, threonine. Provide biotin cofactor Can give alternate path of elimination (carnitine can bind and eliminate propionic acid) Treat secondary affects - ammonia detox and add bicarb to neutralize the acid
95
OTC deficiency
deficient in urea cycle - carbamoyl phosphate will go to pyrimidine synthesis. Ammonia will be extremely elevated
96
OTC treatment
only essential AAs, provide product of citruline, replace the enzyme with a liver transplant, dialysis to remove ammonia + ammonia scavenging meds
97
galactosemia
missing uridyl transferase - cant get from galactose 1 P to glucose 1P
98
tx of galactosemia
restrict substrate (no lactose or galactose),
99
GSD1
glycogen storage disease - glucose will be very low, lactate elevated, triglycerides elevated, uric acid elevated. blood sugars fall VERY fast after short fast
100
enzyme in GSD1
G6Phosphatase - cant regenerate glucose
101
medium chain acyl coA dehydrogenase deficiency (MCAD)
cant oxidize medium chain fatty acids, usually first manifestation is sudden death. fasting hypoketotic hypoglycemia because cant do beta ox of fatty acids
102
how to treat MCAD
avoid fasting, lower fat, higher carb diet. Add carnitine to bind and eliminate FA, treat secondary effects
103
Gauchers
accumulation of storage material in lysosomes - get erlenmeyere flask femur. ALL caused by mutations in B glucocerebrosidase. - cant make fatty acids which include plasma membrane sphingolipids
104
heteroplasmy and threshold effect
relevant in mitochondrial diseases as have all diff mit and only some will express issue.
105
replicative segregation
random allotment of daughter cells during cellular replication so some cells much more affected than others - some body parts more affected than others

McG (11 decks)

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