Nitrogen - Seidler

Question 1

what is the defect in Hartnup disease and what are teh symptoms?
the loss of what amino acid in particular?
what are you unable to make?

Answer 1

defect in transport of neutral and nonpolar a.a., sx: failure to thrive, ataxia, photosensitivity
Tryptophan
Niacin

Question 2

what is the defect in Cystinuria?

what are the symptoms?

Answer 2

defect in transport of dibasic a.a.

kidney stones, + nitroprusside test, renal colic

Question 3

what a.a. are affect in Cystinuria?

Answer 3

Cystine, Lysine, Arginine, Orinthine

Question 4

what is the defect in Maple syrup urine disease?
what a.a. are involved?
what is a common outcome and what can be used for treatment?

Answer 4

deficiency in branched chain alpha-keto acid dehydrogenase
Val, Ile, Leu
mental retardation, Vit B1 (thiamine) for tx

Question 5

What is PKU?
what happens/what builds up?
what smell does it have?

Answer 5

error in phenylalanine hydroxylase
Phe builds up and makes phenyl-ketones, harmful to brain
musty smell

Question 6

what is secondary PKU?

Answer 6

deficiency in THB which is a cofactor for phenylalanine hydroxylase

Question 7

breakdown pathway of Phe to Fumarate

Answer 7

Phe –> Tyr –> p-hydroxyphenylpyruvate –> homogentisate –> maleylacetate –> fumarylacetoacetate –> fumarate

Prime Time Player Has More Fun

Question 8

Trp pathway to Melatonin

Answer 8

Trp –> 5-hydroxytrytophan –> serotonin –> melatonin

Question 9

Trp to Niacin needs what?

Answer 9

Vitamin B6 (PLP)

Question 10

Trp to 5-hydroxytrytophan needs what?

Answer 10

THB

Question 11

Tyr breakdown pathway of adrenergics

Answer 11

Tyr –> dopa –> dopamine –> norepinephrine –> epinephrine –> metanephrine

Question 12

what is alkaptonuria a defect of?

what builds up and how do you diagnose?

Answer 12

defect in homogentisate oxidase
homogentisate/homogentisic acid builds up
bluish-black urine

Question 13

what is tyrosinemia type 1 a defect in?
what is excreted w/what smell?
what is inhibited?

Answer 13

fumarylacetoacetate hydrolase
succinylacetate in urine w/cabbage smell
TCA, biosynthesis of heme at delta-ALA dehydratase

Question 14

what is NE degraded to?
by what?
what special urine test can be used?

Answer 14

VMA
MAO and COMT
test for phenyl mandelic acids (product of VMA) which tests for pheochromocytomas (adrenal medulla tumors)

Question 15

what are the 2 possible causes of homocystinuria?

what builds up?

Answer 15

Vitamin Deficient (B6, B12, folic acid)
defect in cystathionine Beta-synthase (needs B6/PLP)

homocysteine builds up

Question 16

what is a major nitrogen transport system from blain to liver?

Answer 16

Glutamine

Question 17

what is degraded when there is nitrogen in the brain?

Answer 17

alpha-keto glutarate, glutamate

Question 18

what moves nitrogen from the skeletal m. to the liver?

Answer 18

Alanine and Glutamine

Question 19

what is primary vs secondary hyperuricemia?

Answer 19

overproduction vs underexcretion of uric acid

Question 20

how do you get gout?

what is the transporter?

Answer 20

rich purine diet

acidemia stimulates reabsorption via URAT1

Question 21

how is ammonia toxic?
what is inhibited?
what does it cause?

Answer 21

it can traverse biological membranes and cause edema and intercranial HTN
TCA bc alpha-ketoglutarate is depleted
mitochondria dysfunction

Question 22

what is hyperammonemia w/orotic aciduria a defect in?
what builds up?
how is orotic aciduria made?

Answer 22

defect in orinthine transcarbamoylase
carbamoyl phosphate and spills out into the cytoplasm
synthesized by pyrimidine pathway to orotic acid which accumulates

Question 23

how does orotic aciduria occur?

Answer 23

defect in UMP synthase
OR
defect in orinthine transcarbamoylase accompanied by hyperammonemia and reduction in BUN level

Question 24

what is tyrosinemia type II a defect in?
what are you unable to make?
what are the symptoms?

Answer 24

deficiency in tyrosine aminotransferase, build up of Tyr
cannot make p-hydroxyphenylpyruvate
photophobia and skin lesions on feet

Question 25

what is tyrosinemia type III a defect in?

what are the symptoms?

Answer 25

p-hydroxyphenylpyruvate oxidase

intermittent ataxia

Question 26

heme breakdown pathway:

Answer 26

heme –> biliverdin –> bilirubin –> bilirubin + albumin –> indirect bilirubin –> direct bilirubin –> urobilinogen –> urobilin or stercobilin

Question 27

is indirect bilirubin conjugated or unconjugated?

Answer 27

unconjugated

Question 28

defect in UDP-glucuronyl transferase leads to what?

Answer 28

Crigler-Najjar syndrome

Gary Gilbert syndrome

Question 29

Where does reabsorption of amino acids and glucose occur?

Answer 29

PCT