Biochemistry

Question 1

What is ASL and ALT that you will see in your lab reports?

Answer 1

AST-aspartate aminotransferase

ALT-alanine aminotransferase

Both use alpha amino acids and alpha keto acids as substraits to either donate or accept amine groups in response to changes in pyruvate, alanine, aspartate or oxaloacetate.

Question 2

What cofactor do the alpha amino acids use when transfering an amine group to an alpha keto acid?

Answer 2

Pyridoxal: which is reduced to pyridoxamine which then transfers its amine group to an alpha keto acid.

Question 3

You decide to go for a run a burn some sugar off in the process. How will this change nitrogen balance in your body and hoe will your body deal with the change?

Answer 3

Increase glycolysis and thus pyruvate formation, which will then shift the balance (due to mass effect) into the formation of more alanine (in order to export N to the urea cycle).

The amine group from glutamate (via pyridoxal) will end up reducing pyruvate to alanine and oxidizing glutamate to alpha keto glutarate in the process.

The alanine will then be exported from the muscle and transported to the liver then converted into glutamate before being processed in the urea cycle.