Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Medical
  •  Arginosuccinase is  Option: 1 Hydrolase  <div class='qna-op

 Arginosuccinase is

 

Option: 1

Hydrolase

 


Option: 2

Ligase

 


Option: 3

Lyase

 


Option: 4

Oxidoreductase

 


Answers (1)

best_answer

 

 

Steps of Urea Cycle:

1. Synthesis of carbamoyl phosphate:

  • This step takes place in the mitochondria of the liver cells. 
  • Here the ammonium ions react with carbon dioxide (product of mitochondrial respiration) to form carbamoyl phosphate catalyzed by the enzyme carbamoyl phosphate synthetase I. 
  • This is an irreversible, rate-limiting, ATP-dependent reaction and consumes 2 ATP. 

2. Synthesis of citrulline: 

  • Carbamoyl phosphate produced in the first step reacts with ornithine in the presence of ornithine transcarbamoylase to synthesize citrulline. 
  • Just like oxaloacetate in the Krebs cycle, ornithine plays a similar role acting as accepting substrate at each turn of the cycle. 
  • Via a transporter system, this citrulline is now transferred to the cytosol of the liver cells.

3. Formation of argininosuccinate:

  • In this ATP dependent step, the carbonyl carbon of citrulline is attacked by the lone pair of the amine in aspartate to produce argininosuccinate in presence of argininosuccinate synthetase. 
  • In this step, the second nitrogen of urea is incorporated by condensation.
  • ATP is broken down into AMP and pyrophosphate.

4. Breakdown of argininosuccinate:

  • Arginosuccinase promotes the cleavage of argininosuccinate to give arginine and fumarate in a reversible manner. 
  • Fumarate formed here joins the citric acid cycle forming a link between urea and citric acid cycle.

5. Formation of urea:

  • Arginine produced in the earlier step is broken down by arginase to give urea and ornithine. 
  • Ornithine is recycled back to the mitochondria for the next cycle.
     

-

 

 

 

Arginosuccinase promotes the cleavage of argininosuccinate to give arginine and fumarate in a reversible manner. Hence, the correct option is lyase. 

Posted by

sudhir.kumar

View full answer

NEET 2024 Most scoring concepts

    Just Study 32% of the NEET syllabus and Score up to 100% marks

Similar Questions

Trending Articles/News

anam-khan

When will NEET results 2025 be declared? Result date and time, tie-breaking rule
anam-khan

Homeopathy NEET cut-off trends for BHMS AIQ seats; college-wise opening and closing ranks
anam-khan

Who is AIR 1 in NEET 2025? Toppers and their marks in last 5 years

Latest Question