Tumor cells exhibit increased metabolic autonomy compared to non-transformed cells, utilizing nutrients and metabolites to support growth and proliferation. Classic studies highlighted enhanced glycolysis and suppressed oxidative phosphorylation in tumor cells, known as the 'Warburg effect.' However, recent research has focused on the biosynthetic activities required for daughter cell creation, which are equally crucial for tumor growth. This review discusses how tumor cells achieve high rates of nucleotide and fatty acid synthesis, the influence of oncogenes and tumor suppressors on these processes, and the role of glutamine metabolism in enabling macromolecular synthesis in proliferating cells. The review also explores how tumor cells divert glycolytic carbon towards ribose-5-phosphate synthesis and how they synthesize fatty acids and lipids. Additionally, it examines how glutamine metabolism supports biosynthetic activities, including anaplerosis and NADPH production, and how this supports tumor growth and proliferation. The authors conclude that enhanced biosynthetic capacity is a key feature of the metabolic transformation of tumor cells, and that glutamine metabolism plays a critical role in this process.Tumor cells exhibit increased metabolic autonomy compared to non-transformed cells, utilizing nutrients and metabolites to support growth and proliferation. Classic studies highlighted enhanced glycolysis and suppressed oxidative phosphorylation in tumor cells, known as the 'Warburg effect.' However, recent research has focused on the biosynthetic activities required for daughter cell creation, which are equally crucial for tumor growth. This review discusses how tumor cells achieve high rates of nucleotide and fatty acid synthesis, the influence of oncogenes and tumor suppressors on these processes, and the role of glutamine metabolism in enabling macromolecular synthesis in proliferating cells. The review also explores how tumor cells divert glycolytic carbon towards ribose-5-phosphate synthesis and how they synthesize fatty acids and lipids. Additionally, it examines how glutamine metabolism supports biosynthetic activities, including anaplerosis and NADPH production, and how this supports tumor growth and proliferation. The authors conclude that enhanced biosynthetic capacity is a key feature of the metabolic transformation of tumor cells, and that glutamine metabolism plays a critical role in this process.