Neurotransmitters 3 Flashcards
tyrosine derived neurotransmitters
dopamine norepinephrine epinephrine
catecholamines neurotransmitters
fancy word for tyrosine derived neurotransmitters aka dopamine norepinephrine epinephrine
catecholamines neurotransmitters are synthesised from
L-tyrosine
synthesis of the catecholamines neurotransmitters
L-tyrosine
↓ tyrosine hydroxylase
L-3,4-dihydroxyphenylalanine
(L-Dopa) DOPA Decarboxylase
↓ DOPA Decarboxylase
Dopamine
↓ Dopamine B-Hydroxylase
Noradrenaline
↓ phenylethanolamine N-methyltransferase
Adrenaline
decarboxylation of DOPA to form dopamine requires which co-enzyme
pyridoxal phosphate
how is norepinephrine synthesized from dopamine
in a hydroxylation reaction catalyzed by dopamine β-hydroxylase (DBH). (Ascorbic acid, vit. C, and Cu+2).
synthesized in both adrenal medulla and in few neurons
epinephrine
epinephrine synthesis is dependent on the presence of
adequate levels of B12 and folate
neurons outside of adrenal medulla that synthesis epinephrine contain
enzyme that transfer a methyl group from S-Adenosyl methionine to norepinephrine to form epinephrine
rate limiting enzyme in catecholamine synthesis is
tyrosine hydroxylase tyrosine hydroxylase is responsible for the conversion of tyrosine to L-DOPA which is readily converted into dopamine also forms H20
L-tyrosine is formed by
hydroxylation of phenylalanine in the liver when the intake of tyrosine in the diet is low or from diet such as meats fish eggs nuts beans oats wheat
phenylalanine hydroxylase and tyrosine hydroxylase require what as a co-factor
tetrahydrobiopterin
inactivation and degradation of catecholamines
through reuptake into the presynaptic terminal where degradative enzymes are present monamine oxidase (MAO) and catechol-O-methyltransferase (COMT)
oxidizes catecholamine to an aldehyde.
MAO
transfers a methyl group from s-adenosyl methionine to catecholamine or its degradation product
COMT
