Biochem- Ammonia and Urea Cycle

Question 1

What is the brain’s main means to rid ammonia?

Answer 1

-By conversion of glutamate to glutamine

Question 2

What can result from a buildup of glutamine?

Answer 2

-Cerebral edema

Question 3

How do high levels of ammonia cause depletion of ATP in the brain?

Answer 3

-By removing alpha-ketogluterate from the TCA cycle and transaminating it to glutamate to help clear ammonia.

Question 4

If ATP levels fall, what can result?

Answer 4

Coma and Death

Question 5

What can result if there is a deficiency of disorder of the urea cycle?

Answer 5

Hyperammonaemia

Question 6

What are teh two types of hyperammonaemia?

Answer 6

Congenital hyperammonaemia type I and type II

Question 7

What enzyme is deficient in congenital hyperammonemia type I? Is it treatable?

Answer 7

Carbamoyl phosphate synthase.

-Lethal, non-treatable

Question 8

What enzyme is deficient in congenital hyperammonemia type II? Is it treatable?

Answer 8

• OTC
• it is treatable and the most common form