(6) Nitrogen Metabolism (Kinde) Flashcards
When renal biochemistry goes wrong, what is typically produced?
Kidney stones!!!
There are 4 types
Who are the “stars” of nitrogen flow
In the liver
Extrahepatic tissue
In the liver = Glutamate
Extrahepatic tissue = Glutamine
D. Conversion of ammonia to carbamoyl phosphate via carbamoyl phosphate synthase I and NAG activation
What is the major source of nitrogen in your body?
Protein
To produce ammonia
What is the first step of nitrogen removal?
Oxidative deamination via glutamate dehydrogenase
Amino acid resorption defects
Hartnup is due to?
Inability to resorb
NON POLAR AA
Amino acid resorption defects
Cystinuria is due to?
Inability to resorb
DIBASIC AA
BLUE BOX: HIGH YIELD
Hartnup disease
Caused by?
Autosomal recessive disorder
Defect in transporter of non polar/neutral amino acids
BLUE BOX: HIGH YIELD
Hartnup disease
Clinical manifestations?
Manifests in infancy as failure to thrive
Nystagmus
Intermittent ataxia
Termor
Photosensitivity
BLUE BOX: HIGH YIELD
Hartnup disease
AKA?
Pellagra-like dermatosis
BLUE BOX: HIGH YIELD
Hartnup disease
Triggered by?
Sunlight
Fever
Drugs
Emotional/physical stress
Period of poor nutrition
BLUE BOX: HIGH YIELD
Hartnup disease
Treatment?
Niacin repletion
High protein diet
Daily nicotinamide supplementation
BLUE BOX: HIGH YIELD
Hartnup disease
Important aa that is a precursor for a LOT??
Tryptophan
Precursor for serotonin, melatonin, niacin (precursor for NAD)
C. Niacin
D. Phenylalanine
Cystinuria has a defective amino acid transporter for the following amino acids:
Dibasic Amino acids, use COAL mneumonic
C | Cystine
O | Ornithine
A| Arginine
L | Lysine
Defective amino acid metabolism
Probably talking about
PKU (Phenylketonuria)
Classical PKU is due to
Defective phenylalanine hydroxylase (PAH)
If body does not have enough PAH, phenylalanine is not convered to tyrosine
Albinism is due to…
Inability to form melanin pigments
No tyrosinase
Defects in the ___________________ can lead to secondary PKU
Biosynthesis or regeneration of THB
Where do tyrosinemia type I, II and III show up in the phenylalanine to fumarate pathway?
Alkaptonuria is due to defective…
Homogentisate oxidase
Clinical manifestation of alkaptonuria?
“Black urine disease”
Causes homogenistic acid to accumulate
C. Tyrosine
C. Homogentisate oxidase
Gout is characterized by…
High levels of urate in the blood
What can cause a gout flare up?
Diets rich in purines
(beans, spinach, lentils)
Along with
(Alcohol, meat and seafood)
What is the major treatment for gout?
Allopurinol
Sardines, Liver, Sweetbreads, Beans, Beer
B.
Hyperammonemia occurs with…
Defects in any of the 6 enzymes associated with the urea cycle
or with 3 specific transporters
What is carbamoyl phosphate synthetase II?
Cystolic enzyme unique from the mitochondria isoform that functions in the urea cycle
What are the differences between CPSase I and II?
What enzyme is responsible for congugating uncongugated bilirubin?
UDP glucuronyl transferase (UGT)
