Specialized Products of Amino Acids Flashcards
Tyrosine is converted to what? By what enzyme? What cofactors are needed?
DOPA;
Tyrosine hydroxylase;
Tetrahydrobiopterin (BH4)
DOPA is converted to what? By what enzyme? What cofactors are needed?
Dopamine;
DOPA Decarboxylase;
PLP (Vit B6)
Dopamine is converted to what? By what enzyme? What cofactors are needed?
Norepinephrine;
Dopamine B-hydroxylase
Vitamin C
Noepinephrine is converted to what? By what enzyme? What cofactors are needed?
Epinephrine;
Phenylethanolamine N Methyl Transferase;
S-adenoysl methionone (SAM)
A patient comes to you with spastic movements, tremors, loss of memory, mood disturbances and postural instability. You suspect he has ___________, which you know is a neurodegenerative disorder caused by a loss of ________ producing cells in the _________. Tests confirm your suspicion and so you administer _______. This drug is converted to ________ in the brain and improves his symptoms.
Parkinsons disease; Dopamine; Basal ganglia; L-Dopa; Dopamine
Peripheral dopamine formation must be inhibited by administration of what?
Dopa decarboxylase inhibitor along with the L-Dopa
Norepinephrine and epinephrine are degraded by _____and _____ to form______.
MAO (monoamine oxidase)
COMT (Catechol O-methyl transferase
VMA (Vanillyl Mandelic acid - excreted in urine)
Besides degrading Norepinephrine and Epinephrine to VMA, MAO and COMT degrade Dopamine as well to:
HVA (Homovanillic acid -excreted in urine)
What is Pheochromocytoma?
Overproduction of catecholamines by an adrenal medulla tumor.
Serotonin is also known as what?
5-hydroxy tryptamine
Serotonin is synthesized in what?
Gut
Platelets
CNS
Serotonin is synthesized from what?
Tryptophan
Serotonin is metabolized to what? By what enzyme?
5-HIAA (5-hydroxyindole acetic acid);
MAO
What is diagnostically characteristic of Carcinoid syndrome?
Increased 5-HIAA in urine;
because it is caused by a tumor of serotonin producing cells in the GIT (APUD cells)
Melatonin is derived from what?
Serotonin (5-Hydroxy Tryptamine)
Which reactions require Tetrahydrobiopterin?
–Phenylalanine hydroxylase(converts Pheto Tyr)
–Tyrosine hydroxylase(converts Tyr to DOPA)
–Tryptophan hydroxylase(converts Trpto 5-hydroxy tryptophan)
Deficiency of ____________or__________ result in hyperphenylalaninemia& decreased synthesis of neurotransmitters (catecholamines, serotonin).
Dihydrobiopterin synthase
Dihydrobiopterin reductase
What type of neurotransmitter is GABA?
Inhibitory
in CNS
GABA stands for
Gamma amino butyric acid
Glutamic acid (Glutamate) is converted to GABA using what enzyme? What co-factor is required?
Glutamate Decarboxylase
PLP
What cells are involved with GABA reuptake in the CNS?
Glial cells
Histidine is converted to Histamine by what enzyme? Requiring which cofactor?
Amino Acid Decarboxylase
PLP
Creatine can be synthesized from what?
Arginine,
Glycine
SAM (S-adenosyl Methionine)
When muscle is resting, creatine…
accepts P groups from ATP
done by Creatine PK
When muscle is contracting, creatine…
donates P groups to ADP
done by Creatine PK
What is creatine converted to?
Creatinine (spontaneous)
Acute or chronic renal failure does what to serum creatinine levels?
Elevate
What does Nitric oxide synthase catalyze?
Arginine —-> NO
Citrulline is given off
Albinism is a deficiency of what enzyme?
Tyrosinase
deficient conversion of tyrosine to melanin
Glutathione is a tripeptide made up of what three enzymes?
Glutamate (Glutamic acid)
Cysteine
Glycine
Glutathione reductase functions to reduce ______ back to 2 _______ and requires ______ as an electron source.
GSSG
GSH
NADPH
