Purine and pyrimidine metabolism explains how cells build and break down the nucleotide building blocks of DNA and RNA. This course covers de novo purine synthesis and its regulation, and de novo pyrimidine synthesis, including the ATCase reaction and the synthesis of UTP and CTP. You'll examine purine and pyrimidine catabolism and salvage pathways, including how excess uric acid leads to gout and how drugs such as allopurinol intervene. The course then covers deoxyribonucleotide synthesis via ribonucleotide reductase and thymidine synthesis via thymidylate synthase, including the folate-recycling reactions these enzymes depend on, before closing with a look at nucleoside analog drugs used in chemotherapy and antiviral treatment. These pathways connect directly to the drug mechanisms covered elsewhere in the program.