Nitrogen Flashcards
State the main nitrogen-containing molecules of the body.
Nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids (DNA and RNA) and in the energy transfer molecule adenosine triphosphate.
Describe the fate of dietary protein.
The ingested proteins are absorbed and incorporated into the body without undergoing any marked chemical change. 2. The food proteins are first hydrolyzed in the alimentary tract; the products of digestive hydrolysis are then absorbed into the blood and carried to the tissues.
Describe the catabolism of body protein.
Protein catabolism is the breakdown of proteins into absorbable monomers for further degradation or reassembly. Protein catabolism in the intestinal lumen is important for several reasons, 1 of which is mobilizing essential amino acids for absorption.
Describe the formation of urea.
The liver forms it by combining two ammonia molecules ( NH 3) with a carbon dioxide ( CO 2) molecule in the urea cycle.
Describe examples of how metabolic defects in the urea cycle give rise to clinical
problems.
Symptoms of urea cycle disorder are the result of having too much ammonia in your blood (hyperammonemia). Symptoms range from mild to severe and could include: Problems with cognitive development and intellectual challenges. Behavioral changes.
The more “proximal” the enzyme deficiency is, the more severe the hyperammonemia; thus, disease severity in descending order is NAGS deficiency, CPS deficiency, OTC deficiency, citrullinemia, argininosuccinic aciduria, and argininemia.
