E3: neurotransmitters + synthesis of skin pigments

serotonin

derived from trp

regulates sleep/wake cycle + sense perception

LSD + psilocin are derivatives (hallucinogenic drugs)

1. hydroxyl group is added to aromatic ring of trp

2. co2 is removed from the intermediate > serotonin

   • enzyme uses pyridoxal phosphate

psilocin

similar structure to serotonin

catecholamines

norepinephrine + dopamine

1. mixed function oxidase adds OH to Phenylalanine >tyrosine

• uses Cytochrome p450 cofactor

2 . OH added to tyrosine > 3 , 4 dihydroxyphenylalamine (DOPA)

3. CO2 is removed from DOPA > dopamine

4. OH is added to dopamine > norepinephrine

5. SAM adds methyl group to norepinephrine > epinephrine (hormone)

• in other tissues like the adrenal gland

synthesis of skin pigments

DOPA undergoes side reaction

1. phe > tyr > dopa

2. dopa > red pigments

3. remove Co2 from red pigments + molecule undergoes polymerization > melanin

parkinson’s disease

decrease in dopamine or it is broken down too quickly before norepinephrine is made

• not enough or a defect in the enzyme that converts DOPA > dopamine or tyrosine > DOPA

abnormal muscle contractions

hereditary

phenylketonuria (PKU)

cant convert phe to tyr

either made + not functional or not made

characterized by: mental impairment + deficiencies in pigment

treated with a diet low in phe or give the baby tyr