Protein and Amino Acid Metabolism Supplement

Question 1

What amino acids come from 3-Phosphoglycerate?

Answer 1

Serine –> cysteine, glycine

Question 2

What amino acids come from Glucose 6-Phosphate?

Answer 2

Histidine, but only a small amount from gut bacteria, considered an essential AA.

Question 3

What AA comes from pyruvate?

Answer 3

alanine

Question 4

What AA’s come from oxaloacetate and also go back into it for degradation?

Answer 4

asparagine and aspartate

Question 5

What amino acids come from alpha keoglutarate?

Answer 5

glutamate –> glutamine and proline

Question 6

What does the degradation of ketogenic AA produce?

Answer 6

Acetyl CoA

Question 7

What does the degradation of glucogenic AA produce?

Answer 7

pyruvate or other intermediates of the TCA cycle

Question 8

What AAs enter the TCA through fumarate?

Answer 8

Phe and Tyr

Question 9

What AAs enter the TCA through Succinyl CoA?

Answer 9

Ile, Val, Met, Thr

Question 10

What AAs enter the TCA through alpha ketoglutarate

Answer 10

gln, his, arg, pro (almost all w/ N grp) through glutamate

PHAG

Question 11

what enzyme catalyzes the reaction of methionine to homosysteine?

Answer 11

homocysteine methyl transferase

Question 12

what enzyme catalyzes the rxn of homocysteine to cystathionine?
What cofactor is required? What vitamin is it derived from?

Answer 12

cystothionine synthase
Pyridoxal phosphate (PLP); comes from vitamin B6

Question 13

degradation of what amino acid is screwed up in the diseases hyperhomocysteinemia and homocystinuria?

Answer 13

methionine( –> homocysteine –> cystathionone –> alpha ketobutyrate)

Question 14

what organ systems are most affected from hyperhomocysteinemia and homocystinuria?

Answer 14

eye
skeletal
cns
vascular

Question 15

What amino acids can’t be broken down in maple syrup urine disease?

Answer 15

branched chain amino acids

Question 16

what enzyme is used to break down Val, Ile, and Leu?

What disease results from deficient activity of this enzyme?

Answer 16

BCKD

MSUD

Question 17

In the brain, what amino acids are used to remove ammonia?

Answer 17

glu and gln

alpha keto glutarate –>glu –>gln –to liver–>gln –>glu and ammonia goes to urea cycle

Question 18

In muscle, what amino acids are used to remove excess ammonia?
What enzymes are essential to do this?

Answer 18

alanine and glutamate
ALT changes pyruvate to ala w/ a nh3 and then turns it back to pyruvate in liver
GLDH removes NH4 in liver and puts it in urea cycle

Question 19

What amino acids is creatine made from?

Answer 19

Met, Arg, Gly

MAGazINE

Question 20

What enzyme changes creatine to phosphocreatine and generates ATP?

Answer 20

creatine kinase

Question 21

Alkaptonuria is caused by a deficiency in what enzyme?

Answer 21

homogentistic acid oxidase (tyrosine –> homogentisate in the breakdown of phenylalanine)

Question 22

What is the breakdown path of Phenylalanine?

Answer 22

Phe –> Tyr –> Homogentisate –>–> fumarate

Question 23

PKU is due to what?

Answer 23

Deficiency in phenylalanine hydroxylase

Question 24

In PKU, what molecules accumulate?

Answer 24

phenylactate and phenylacetate

Question 25

What is the order of the urea cycle

Answer 25

NH4+ –> carbamoyl Pi –> citrulline –into mito –>citrulline –> argino succinate –> arginine –H20 comes in and Urea comes out –> ornithine
(OCAA)

Question 26

What does ornithine transcarbomoylase do?

Answer 26

Carbamoyl Pi + ornithine –> citrulline

Urea cycle

Question 27

What does arginosuccinate synthase do?

Answer 27

citrulline –> arginosuccinate

Urea cycle

Question 28

What does Arginosuccinate lyase do?

Answer 28

Arginosuccinate –> arginine

Urea cycle

Question 29

What does arginase do?

Answer 29

Arginine –> ornithine
Where water goes in and urea goes out!
Urea cycle

Question 30

What are the common derivatives of tyrosine?

Answer 30

Dopamine –> norepinephrine –> epinephrine
thyroid hormone
melanin

Question 31

What are derivatives of Tryptophan you should know?

Answer 31

Niacin –> nadh

serotonin –> melatonin

Question 32

What derivative of Serine should you know?

Answer 32

Acetylcholine

Question 33

What derivative of glutamate should you know?

Answer 33

GABA