INBORN ERRORS OF UREA CYCLE

Question 1

Rate limiting steps/Committed steps of the Urea Cycle

STEP 1: Catalyzed by ______
STEP 2: catalyzed by _______
STEP 5 catalyzed by _______

Answer 1

CPS I
Ornithine transcarbamoylase
Arginase

Question 2

________ moles of ammonia are detoxified PURR turn

Answer 2

2 moles

Question 3

2 moles of ammonia are detoxified PURR turn

1 mole is in the ___ reaction
1 mole is the ____ reaction in the form of aspartic acid

Answer 3

1st reaction
3rd reaction

Question 3

ATP used: ___- moles of ATP
in what reactions?

Answer 3

4 moles
1st and 3rd reaction

Question 4

INBORN ERROR
Hyperammonemia type I

Answer 4

CPS I

Question 5

INBORN ERROR
Hyperammonemia type II

Answer 5

Ornithine transcarbamoylase

Question 6

INBORN ERROR
Citrullinemia

Answer 6

Argininosuccinate synthetase

Question 7

INBORN ERROR
Argininosuccinate Aciduria

Answer 7

argininosuccinase

Question 8

INBORN ERROR
Arginemia

Answer 8

arginase

Question 9

___________ deficiency is one of the proximal urea cycle defects and is due to a complete or partial deficiency of the mitochondrial enzyme ornithine transcarbamoylase

Answer 9

ornithine transcarbamoylase deficiency

Question 10

________ is converted to benzoyl-CoA which combines with glycine to form hippurate

Answer 10

benzoate

Question 11

______ is converted to phenylacetate by oxidation

Answer 11

phenylbutyrate

Question 12

ways of detoxifying ammonemia

R
G
U
A

Answer 12

reversal of glutamate dehydrogenase reaction
glutamine formation
urea formation
asparagine formation

Question 13

carbamoyl phosphate synthetase I initiates _____________-

Answer 13

urea biosynthesis

Question 14

carbamoyl phosphate plus ornithine forms ____________

Answer 14

citrulline

Question 15

citrulline plus aspartate forms _______________

Answer 15

argininosuccinate

Question 16

cleavage of argininosuccinate forms __________ and ________

Answer 16

arginine and fumarate

Question 17

cleavage of arginine releases ______ and reforms ________

Answer 17

urea
ornithine

Question 18

___________ is the pacemake enzyme of the urea cycle

Answer 18

carbamoyl phosphate synthetase I