AA Flashcards
How many essential AA are there
10
What are the essential AA
“PVT TIM HaLL”
- Phe
- Val
- Trp
- Thr
- Ile
- Met
- His
- Leu
- Lys
Which AA are glucogenic
- Met
- His
- Val
Which AA are glucogenic/ketogenic
- Ile
- Phe
- Thr
- Tryp
Which AA are purely ketogenic
- Leu
- Lys
Which AA are required during periods of growth
Arginine and Histidine
Which AA are increased in histones
Arginine and lysine
What AA makes tyrosine, dopamine, NE, Epi
Phe
Melanin comes from
Dopa (from tyrosine, from Phe)
Which AA makes NAD+/NADP+ and melatonin
Tryptophan
- Niacin –> NAD+/NADP+
- Serotonin –> Melatonin
Which AA makes heme
Glycine
Makes prophyrin (w/B6) which makes heme
Which AA makes GABA (w/B6) and Glutathione
Glutamate
Which AA makes creatine, urea, nitric oxide
Arginine
BH4 (tetrahydrobiopterin) is required for what processes
- Phe to Tyrosine
- Tyrosine to Dopa
- Tryptophan to serotonin
- Arginine to Nitric oxide
B6 is required for which AA processes
- Dopa to dopamine
- Tryptophan to Niacin (w/B2)
- Tryptophan to serotonin (w/BH4)
- Histidine to Histamine
- Glycine to Porphyrin
- Glutamate to GABA
Vitamin C is required for what AA process
Dopamine to NE
SAM is required for what AA process
NE to Epi
What are the steps to making catecholamines
Phe–>Tyrosine–>DOPA–>Dopamine–>NE–>Epi
What is defective in PKU
phenylalanine hydroxylase
What is defective in Alkaptonuria
Homogentisate oxidase
What is defective in albinism
Tyrosinase
Carpidopa inhibits what
DOPA decarboxylse
no DOPA to Dopamine
Cortisol acitvates
phenylethanolamine-N-methyltransferase
NE to Epi
Epi is turned into Metanepherine by
COMT
NE is turned into normetanephrine (vanillylmandelic acid) by
COMT
PKU is d/t
decrease Phe (aromatic AA) hydroxylase or decrease BH4 cofactor (malignant PKU)
AR
screening 2-3 days after birth
What becomes essential in PKU
Tyrosine
Increase in Phe causes
increase in phenyl ketones in urine
Symptoms of PKU
- intellectual disability
- growth retardation
- seizures
- fair complexion
- eczema
- musty body odor
How to treat PKU
- decrease Phe
- increase tyrosine in diet
- BH4 supplementation
Why are PKU babies normal at birth
maternal enzyme present during fetal life
What must PKU patients avoid
artificial sweetener aspartame
has Phe
Maple syrup urine disease is d/t
AR: blocked degradation of branched AA d/t decreased branched chain alpha-ketoacid DH (B1)
- Ile
- leu
- val
In maple syrup disease there is an increase in what
alpha-ketoacids in blood, especially those of leucine
How to treat maple syrup disease
- restrict branched chain AA (val, ile, leu) in diet
- thiamine supplementation
Maple syrup disease symptoms
- urine smells like burnt sugar/maple syrup
- vomiting
- poor feeding
- severe CNS defects
- interllectual disability
- death
Alkaptonuria is d/t
AR congenital deficiency of homogentisate oxidase in degradative path of tyrosine to fumarate
- pigment forming homogentisic acid builds up in tissue
- usually benign
Symptoms of alkaptonuria
- bluish-black connective tissue, ear cartilage, sclerae (ochronosis)
- urine turns black on prolonged exposure to air
- possible debiliating arthalgias (homogentisic acid toxic to cartilage)
Homocystinuria is d/t what 4 causes
AR
- cystathionine deficiency
- decreased affinity of cystathionine synthase for pyridoxal phosphate
- methionine synthase deficiency
- MTHFR deficiency
How to treat homocystinuria d/t cystathionine synthase deficiency
- decrease methionine
- increase cysteine, B6, B12, folate in diet
How to treat homocystinuria d/t decrease affinity of cystathionine synthase for pyridoxal phosphate
increase B6 (alot) and cysteine in diet
How to treat homocystinuria d/t methionine synthase deficiency
increase methionine in diet
How to treat homocystinuria d/t MTHFR deficiency
increase folate in diet
All forms of homocystinuria cause
- increase homocysteine in urine
- osteoporsis
- marfanoid habitus (binds to fibrillin-1)
- ocular changes (down and in lens subluxation)
- cardio effects (thrombosis and atherosclerosis, stroke and MI)
- Kyphosis
- intellectual disability
- fair complexion
Why does homocystinuria cause thrombosis
homocysteine binds to endothelial cells = proinfammatory cytokines
Cystinuria is d/t
hereditary defect of renal PCT and intestinal AA transporter that prevents reabsorption of “COLA”
- cystine
- ornithine
- lysine
- arginine
what can too much cystine in urine do
hexagonal cystine stones
how to treat cystinuria
- urinary alkalinization (potassium citrate, acetazolamide)
- chelating agents (penicillamine) increase solubility of stones
- good hydration
How to diagnose cystinuria
AR
urinary cyanide-nitroprusside test
What is propionic acidemia d/t
AR deficiency of propionyl-CoA carboxylase
excess propionyl-CoA
decrease methymalonic acid
findings of propionic acidemia
- poor feeding
- vomiting
- hypotonia
- anion gap metabolic acidosis
- hepatomegaly
- seizures
How to treat propionic acidemia
low protein diet that does not have ile, met, thr, val
Substances that metabolize into propionyl-CoA cause you to VOMIT
Valine
Odd-chain FA
Methionine
Isoleucine
Threonine
