Question

Make an outline chart to show how urea is made from ammonia and aspartic acid in the ornithine urea cycle

Answer 1

It is that outline chart.

Answer 2

1. Ammonia is first converted into carbamoyl phosphate which is catalyzed by enzyme carbamoyl phosphate synthetase I. This reaction  also required 2 ATP molecules. The carbamoyl phosphate then enters the urea cycle.
2. Carbamoyl phosphate is converted into citrulline by enzyme ornithine transcarbamoylase with the release of a phosphate group.
3. A condensation reaction takes place between the amino group of aspartate and the carbonyl group of citrulline to form arginosuccinate. this reaction depends on ATP and is catalyzed by argininosuccinate synthetase.
4. With the help of an enzyme argininosuccinase, the argininosuccinate cleaved into arginine and fumarate.
5. Arginine is cleaved to form urea and ornithine which is catalyzed by an enzyme arginase.
6. The ornithine is transported back to the mitochondria to begin urea cycle again.