Urea Cycle

Question 1

Where is excess glutamate metabolised in the urea cycle?

Answer 1

The mitochondria of hepatocytes in the liver

Question 2

Which two amino acids are received by the liver in the urea cycle?

Answer 2

Glutamine and alanine

Question 3

What is the end product of amino acid degradation in the urea cycle?

Answer 3

Glutamate

Question 4

Glutamine is broken down into glutamate during the urea cycle, what does the amino acid group that is released during this process form?

Answer 4

Urea

Question 5

Which amino acids donate an amino group in the urea cycle?

Answer 5

Glutamate, Glutamine, Aspartate

Question 6

What process does glutamate undergo in the urea cycle? What does it produce?

Answer 6

Oxidative deamination
Produces:
- alpha-ketoglutarate
- NH3 (which binds with CO2 and forms urea)

Question 7

Which organ converts urea to urine?

Answer 7

Kidney

Question 8

How many nitrogen molecules are there per urea molecule?

Answer 8

2

Question 9

What process does carbamoyl phosphate inhibit?

Answer 9

Glutamine synthesis

Question 10

What are glycogenic amino acids used for?

Answer 10

To make glucose

Question 11

What are ketogenic amino acids used for?

Answer 11

To make acetyl CoA