Amino acid catabolism and urea cycle

In this talk, we turn our attention to Amino Acid Catabolism and Urea Cycle, framing our discussion around the roles of amino acids as metabolic fuels and the need for their safe catabolism, beginning with deamination and culminating in urea formation. We will discuss the biochemical steps of nitrogen removal and transport, key reactions and regulation within the urea cycle, and how these processes interface with overall metabolism. Lastly, the lecture will highlight the clinical importance of the urea cycle by examining disorders arising from enzyme defects and impaired nitrogen disposal.. Amino acids are not only protein building blocks but also metabolic fuels, especially when carbohydrates and fats are low. Unlike carbohydrates and fats, amino acids lack specialised storage. Excess amino acids or those from protein breakdown are catabolised, beginning with deamination to remove the alpha-amino group, leaving a carbon skeleton converted into metabolic intermediates. Because free ammonia is highly toxic, especially to neural tissue, it must be safely disposed of. In humans, nitrogen is converted to urea in the liver and excreted by the kidneys. This lecture explores amino acid deamination, nitrogen transport and disposal, regulation of the urea cycle, and the importance of this process in health and disease. The first major step in most amino acid catabolism is transamination, where the amino group where the amino group is transferred to alpha-ketoglutarate,