BIOC 311 Lecture Notes - Lecture 23: Carbamoyl Phosphate, Hans Adolf Krebs, Glutamine Synthetase

• School: McGill University
• Department: Biochemistry
• Course: BIOC 311
• Professor: Maxime Denis

Document Summary

Some reactions occur in the matrix, while others occur in the cytosol they"re compartmentalized. Glutaminase: converts glutamate glutamine inside the liver to generate nh3. Gdh: converts glutamate glutamine to also produce nh3: this is the origin of the nh3 that enters the urea cycle. In order to enter the urea cycle, you must generate the first substrate, which is carbamoyl. Phosphate (made up of a co2, amine, and phosphate groups: this substrate is generated by the enzyme cps1. When you have plenty of atp inside the cell, you activate cps1. There is then a 2nd reaction that takes place involving another atp molecule where another phosphate is added but to carbamate to generate carbamoyl phosphate: this step is a priming step for otc. Summary cps1: bicarb + atp carboxyphosphate + nh3 carbamate + atp carbamoyl phosphate. Phosphates are added to the central carbon (with the =o)