q_____________? - sarim

[ArchivalUser]

Which of the following pairs of enzymes is involved in the conversion of amino acid nitrogen into two compounds that directly provide the nitrogen of urea ?

A- L-Amino acid oxidase and Decarboxylase

B-Carbamoyl phosphate synthetase I and Glutamic-Oxaloacetic Transaminase

C-Glutamic-Oxaloacetic Transaminase and Monoamine Oxidase

D-Glutamine Synthetase and Glutaminase

E-Serine dehydratase and Glutamic dehydrogenase

[ArchivalUser]

?D

[ArchivalUser]

DDD

[ArchivalUser]

DD

[ArchivalUser]

How ?

plz.

[ArchivalUser]

Glutamine is the major carrier of excess body nitrogen
Glutaminase breakdown glutamine into glutamate and ammonia which is in turn converted to urea
Glutamine synthase convert glutamate back to glutamine by utilizing ammonia
http://jcb.rupress.org/content/157/3/349/F1.medium.gif

[ArchivalUser]

Glutamine synthase captures excess nitrogen by aminating glutamate to form Glutamine.
Glutamine is a carrier of excess nitrogen from tissue

Glutamate + ATP + NH3 → Glutamine + ADP + phosphate

In kidney Glutaminase deaminate the glutamine......eleminate the amino group as ammonium ion in urine

Glutamine + H2O → Glutamate + NH3

[ArchivalUser]

Glutamine synthetase enzyme present in most tissues of our body.
It convert glutamine to glutamate giving off ammonia during reaction.

Glutaminase enzyme is present in intestine.
It converts glutamine to glutamate giving off ammonia during reaction.

Ammonia from both reaction is used in liver for urea cycle.

[ArchivalUser]

what about "E" ?

[ArchivalUser]

I can't see any direct role for serine dehydratase in urea synthesis!