Urea cycle, 1-C metabolism, and Catabolism of Phenylalanine & Tyrosine Pathways

Urea cycle step 1

ornithine and carbamoyl phosphate form citrulline

Urea cycle step 1 enzyme

ornithine transcarbamoylase

Urea cycle step 2a

citrulline forms citrullyl-AMP intermediate

Urea cycle step 2b

intermediate to argininosuccinate

Urea cycle step 2 enzyme

argininosuccinate synthetase

Urea cycle step 3

argininosuccinate forms fumarate or arginine

Urea cycle step 3 enzyme

argininosuccinase

Urea cycle step 4

arginine forms ornithine and urea (byproduct)

Urea cycle step 4 enzyme

arginase

1-C metabolism step 1

methionine with ATP forms S-adenosyl-methionine

1-C metabolism step 1 enzyme

methionine adenosyl transferase

1-C metabolism step 2

S-adenosyl-methionine forms S-adenosyl-homocysteine

1-C metabolism step 2 enyzme

variety of methyl transferases

1-C metabolism step 2 byproduct

R group with CH3 (R group was put into reaction)

1-C metabolism step 3

S-adenosyl-homocysteine forms homocysteine (reversible)

1-C metabolism step 3 enzyme

hydrolase

1-C metabolism step 3 byproduct

H2O enters reaction and adenosine exits

1-C metabolism step 4

homocysteine forms methionine

1-C metabolism step 4 enzyme

methionine synthase

Catabolism step 1

phenylalanine forms tyrosine

Catabolism step 1 enzyme

phenylalanine hydroxylase

Catabolism step 1 coenzymes

O2 (forms H20), NADH (NAD), tetrahydrobiopterin

Catabolism step 1 defect in enzyme

PKU

Catabolism step 2

tyrosine forms p-hydroxyphenylpyruvate

Catabolism step 2 enzyme

tyrosine aminotransferase

Catabolism step 2 byproduct

alpha-ketoglutarate forms glutamate

Catabolism step 2 defect in enzyme

tyrosinemia II

Catabolism step 3

p-hydroxyphenylpyruvate forms homogentisate

Catabolism step 3 enzyme

p-hydroxyphenylpyruvate dioxygenase

Catabolism step 3 byproduct

O2 forms CO2

Catabolism step 3 defect in enzyme

tyrosinemia III

Catabolism step 4

homogentisate forms maleylacetoacetate

Catabolism step 4 enzyme

homogentisate 1,2-dioxygenase

Catabolism step 4 byproduct

O2 forms H+

Catabolism step 4 defect in enzyme

alkaptonuria

Catabolism step 5

maleylacetoacetate forms fumarylacetoacetate (H2O put into reaction)

Catabolism step 5 enzyme

maleylacetoacetate isomerase

Catabolism step 6

fumarylacetoacetate forms fumarate and acetoacetate

Catabolism step 6 enzyme

fumarylacetoacetatase

Catabolism step 6 defect in enzyme

tyrosinemia I

Catabolism step 7

acetoacetate forms acetoacetyl-CoA

Catabolism step 7 enzyme

3-ketoacyl-CoA transferase