Question | Answer |
Lecture 43 | Important Amino Acid Metabolites |
Amino acids are also precursors of ___. | neurotransmitters (catecholamine, serotonin, histamine) |
Glutamate can be converted to: | GABA, proline, and ornithine |
Glutamate is a component of ___. | glutathione |
Glutathione is made in the ___. | liver |
___ serves as precursors for the head group of phospholipids (ethanolamine, choline). | Serine |
Serine carbon skeletons convert to ___, with sulfur transferred from ___. | cysteine, homocysteine |
___ provides the methyl group additions to ethanolamine to make choline. | SAM |
___ can serve as a neurotransmitter, primarily in inhibitor interneurons. | Glycine |
Loss of methyl by SAM in norepinephrine and serotonin produces ___ and ___, respectively. | epinephrine, melatonin |
Reactions involving methyl transfer by ___ are irreversible. | SAM |
___ B12 is the most stable form. | Methylated |
Homocysteinemia | Elevated levels of homocysteine linked to cardiovascular and neurological disease, can involve B12 and folic acid deficiencies (reducing methionine synthetase activity) |
Homocysteine can be reduced by reaction with ___ to form cystathionine. | serine |
Neural tube defects can be prevented with ___ supplements. | folic acid |
___ and ___ are precursors to neurotransmitters and pigments. | Phenylalanine and tyrosine |
Phenylalanine conversion can yield neurotransmitters ___, ___, and ___. | dopamine, norepinephrine, epinephrine |
Catechol | A phenyl ring with two adjacent hydroxyl groups |
___ is required at each hydroxylation step in phenylalanine conversion. | Tetrahydrobiopterin |
Adequate levels of ___ and ___ are needed in phenylalanine conversion. | B12 and folate |
Inhibitors of catecholamine and serotonin degradation work as ___ (increase dopamine levels). | antidepressants (i.e. MOA inhibitor, COMT inhibitor) |
Parkinson’s Disease | Tremors and progressive disease, loss of cells that form dopamine from tyrosine, treated with L-dopa/monoamine oxidase (MOA) inhibitors/catechol O-methyltransferase (COMT) inhibitors |
Ablinism | Light pigmentation/mentally and neurologically normal/photosensitivity, defect in tyrosinase (tyrosine hydroxylase) where tyrosine cannot be converted to melanin |
Formation of catecholamine from tyrosine is dependent on ___. | biopterin |
Tyrosine hydroxylase contains ___ and yields ___ (___). | pyridoxal phosphate, dihydroxyphenylalanine (DOPA) |
DOPA decarboxylase forms ___. | dopamine |
___ is converted to serotonin and melatonin. | Tryptophan |
Degradation of serotonin forms ___ (___), marker of serotonin deficiency. | 5-hydroxyindole acetic acid (5-HIAA) |
Cysteine can be converted to ___, involved in neurodevelopment and conjugation with bile acids, and generation of ___. | taurine, pyruvate |
Tryptophan is the precursor to __% of the body’s pyridine nucleotides, remainder from diet. | 50% |
SAM donates methyl groups to lysine to form ___. | carnintine |
___ serves as a cofactor in catalyzing disulfide bond formation of cysteine –SH groups. | glutathione |