Misc. Proteins Flashcards
What three amino acids contribute to creatinine?
glycine, arginine and ornithine
Where does the nitrogen in creatinine come from?
guanidinoacetate
What is the function of creatinine phosphate?
energy reserve for muscles
Specifically, how is this accomplished?
creatine phosphate can phosphorylate ADP to ATP
How is creatinine formed?
self cyclization
Where is creatinine formed and released from?
muscle cells
What co-factor does phenylalanine hydroxylase require?
THBtn
Thyroid hormones are iodinated versions of what?
tyrosine
What is the function of thyroid peroxidase?
iodination of tyrosine
Where is thyroglobulin degraded? What does this release?
lysosomes
T3 and T4
What is the molecular function of tyrosinase?
converts tyrosine to DOPA and DOPA to dopaquinone
Where does melanin synthesis begin?
golgi of melanocytes
What is dopaquinone synthesized into?
melanin
What is the main function of melanin?
protect against UV radiation
What tissues are melanocytes found in?
skin and hair follicles
Albinism is caused by what?
loss of tyrosinase activity
What two products are derived from tryptophan?
serotonin and melatonin
What two tissues are rich in serotonin?
platelets and GI tract
What two steps are down to tryptophan to make serotonin?
hydroxylation and decarboxylation
What enzyme hydroxylates tryptophan?
tryptophan hydroxylase
What co-factor is required for tryptophan hydroxylase?
THBtn
What is the first step in the conversion of serotonin to melatonin?
N-acetyltransferase converts serotonin to N-acetylserotonin
What is the second step in the conversion of serotonin to melatonin? What does that enzyme require?
methylation by hydroxyindole-O-methyltransferase
SAM
What is the third product that tryptophan can be converted into?
niacin