 They are prepared by reaction of carbamoyl chlorides with alcohols, the addition of alcohols to isocyanates, and the reaction of carbonate esters with ammonia.The enzyme carbamate kinase, involved in several metabolic pathways of living organisms, catalyzes the formation of carbamoyl phosphate C(=O)O

One hemoglobin molecule can carry four molecules of carbon dioxide to the lungs as carbamate groups formed by reaction of with four terminal amine groups of the deoxy form.The resulting compound is called carbaminohaemoglobin.