Amino Acid Pathways

Question 1

What is histidine metabolized to?

Answer 1

glutamate

Question 2

Methionine, valine, isoleucine, and threonine can be converted to what?

Answer 2

propionyl CoA -> methylmalonyl CoA -> succinyl CoA

Question 3

Valine is metabolized to what?

Answer 3

propionyl CoA and eventually, succinyl CoA

Question 4

Isoleucine is metabolized to what?

Answer 4

acetyl CoA and propionyl CoA (and eventually, succinyl CoA)

Question 5

Leucine is metabolized to what?

Answer 5

acetyl CoA and acetoacetate

Question 6

Tryptophan can be metabolized to what?

Answer 6

formate, alanine, and acetoacetate

Question 7

Phe –> Tyr —–> ?

Answer 7

acetoacetate and fumarate

Question 8

What amino acids can be turned into pyruvate?

Answer 8

cysteine, tryptophan, serine, threonine, alanine, and glycine

CW STAG

Question 9

What amino acids can be turned into acetyl CoA?

Answer 9

lysine, tryptophan, isoleucine, and threonine

KWIT

Question 10

What is the pathway from methionine to succinyl CoA?

Answer 10

met -> S-adenosylmet. (SAM) -> S-adenosylhomocys. -> homocys. -> cystathionine -> α-ketobutyrate -> propionyl CoA -> succinyl CoA

Question 11

What are arginine and proline metabolized to?

Answer 11

glutamate

Question 12

What are the essential amino acids?

Answer 12

MILK WiTH Fortified Vitamins and Arginine

aa corresponding to the capital letters

Question 13

Glutamine is made from what?

Answer 13

glutamate, which is made from α-ketoglutarate

Question 14

What is aspartate made from?

Answer 14

oxaloacetate

Question 15

What is asparagine made from?

Answer 15

Aspartate

Question 16

What is proline and ornithine made from?

What is made from ornithine?

Answer 16

glutamate with glutamic-γ-semialdehyde intermediate

arginine

Question 17

What is made from phenylalanine?

Answer 17

tyrosine

Question 18

What 3 amino acids come from a glycolytic intermediate?
(3-phospho-glycerate)

One of them requires a methyl donation from methionine. Which 1?

Answer 18

serine, glycine, and cysteine (S –> G and C)

cysteine

Question 19

Besides from serine from 3-phospho-glycerate, what other way can glycine be made?

Answer 19

from choline

Question 20

Tyr is made from what amino acid via what enzyme?

What cofactor is needed?

Answer 20

Phe via phenylalanine hydroxylase; tetrahydrobiopterin

Question 21

Glutathione is made by an ATP fueled condensation of what 3 amino acids?

Answer 21

glutamate, cysteine, and glycine

Question 22

Creatine is made from what amino acid?
What other amino acid input is needed?
What donates the needed methyl group?

Answer 22

glycine
arginine
SAM

Question 23

Nitric Oxide is made from what amino acid? What else is produced?

Answer 23

arginine; citrulline

Question 24

What is the pathway starting with tyrosine and ending with epinephrine?

Answer 24

Tyr –> DOPA (tyr. hydroxylase, rate limiting) –> Dopamine –> NE –> E

Question 25

Serotonin is made from what amino acid?

What cofactor is needed for the aa hydroxylase?

Answer 25

tryptophan; tetrahydrobiopterin

Question 26

Histamine is made from what amino acid?

Answer 26

histidine

Question 27

What is the pathway for heme biosynthesis?

Answer 27

succinyl CoA + glycine (δ aminolevulinate synthase, rate limiting, inhibited by HEMIN) –> δαminolevulinate x2 –> porphobilinogen x4 –> linear tetrapyrrole (uroporphyrinogen I) –> uropor. III –> copropor. III –> protoporphyrin IX –> heme

Question 28

What is the pathway for heme breakdown?

Answer 28

heme –> biliverdin –> bilirubin –> 2 glucoronic acid (liver) or urobilinogen/stercobilin (gut)