Disposal Of Ammonia And The Urea Cycle Flashcards
The major source of ammonia for urea formation is
Ammonium ion (NH4)
Anaerobic respiration in the muscle could also produce ammonia via the __
AMP deaminase activity
What are the two pathways used to transport ammonia
1) glucose-alanine cycle
2) glutamine cycle
Glutamine cycle reaction is catalysed by an extra hepatic tissue enzyme called _
Glutamine synthetase
Organisms that secrete Their nitrogen as ammonia are collectively called _
Ammonotelic
Terestial animals that secrete their nitrogen as ammonia are called
Ureotelic
Birds that secrete their ammonia as Uric acid are called
Uricotelic
Urea cycle is also known as
Krebs-henseleit cycle
The quantity of urea excreted at any given time …
Is directly proportional to the total protein metabolism
The compartmentalization of reactions is necessary in order to
Bypass the feedback inhibition that would other wise interfere with urea biosynthesis in high ammonia concentration
What are the five reactions of the urea cycle
1) synthesis of carbamoyl phosphate
2) synthesis of citrulline
3) synthesis of argininosuccinate
4) cleavage of argininosuccinate
5) cleavage of arginine
What enzyme catalyses reaction 1 of the urea cycle ?
Carbamoyl phosphate synthetase 1
Enzyme of the second reaction
Ornithine carbamoyl transferase
The second urea nitrogen is formed in which reaction
The third (synthesis of argininosuccinate)
_ is the immediate precursor of urea
Arginine
The fourth reaction is catalyzed by _
Argininosuccinase OR argininosuccinate lyase
Which enzyme of urea cycle is not found in the kidney or intestinal mucosa
Arginase
The aspartate-argininosuccinate shunt entails
Fumarate is converted to Malate and then to Oxaloacetate
The last reaction of urea cycle is catalysed by
Arginase
__ is the rate limiting enzyme of the urea cycle
Carbamoyl phosphate synthetase 1
