Selective Amino Acid Metabolism Part I

Question 1

Which 2 amino acids are purely ketogenic?

Answer 1

lysine and leucine

Question 2

What converts phenylalanine to tyrosine?

Answer 2

phenylalanine hydroxylase (PAH) with BH4

Question 3

What enzymes require BH4?

Answer 3

• phenylalanine hydroxylase (PAH)
• tyrosine hydroxylase
• tryptophan hydroxylase

Question 4

What are the 4 probable sites for defects in amino acid metabolism

Answer 4

tyrosine transaminase -> type 2 tyrosinemia
p-hydroxyphenylpyruvate hydroxylase -> neonatal tyrosinemia
homogentisate oxidase -> alkaptonuria
fumarylacetoacetate hydroxylase -> the 1 tyrosinemia

Question 5

What is the rate limiting steo in synthesis of neurotransmitter?

Answer 5

tyrosine hydroxylase

Question 6

What coenzyme is needed to convert L-tyrosine to Dopa

Answer 6

BH4

Question 7

What coenzyme isneeded to convert Dopa to Dopamine

Answer 7

PLP and Vit B6

Question 8

What coenzyme isneeded to convert Dopamine to Norepienephrine

Answer 8

Cu2+ and Vitamin C

Question 9

What is indicative of dopamine degredation in Parkinson’s

Answer 9

homovanillic acid in CSF

Question 10

what is a major inhibitory neurotransmitter of the CNS?

Answer 10

GABA

Question 11

what are the major excitatory neurotransmitters?

Answer 11

glutamate and aspartate

Question 12

What is the major inhibitory neurotransmiter of the spinal cord?

Answer 12

glycine