The biochemical processes of metabolism by which molecules are synthesized or built up. Often anabolism is a reductive process in which carbons have hydrogen atoms added. Fully saturated fatty acids are the most reduced form of carbon. NADPH is the primary electron donator for anabolic reactions.
Gluconeogenesis is much like glycolysis only the process occurs in reverse. Gluconeogenesis is the metabolic process by which organisms produce sugars (namely glucose) for catabolic reactions from non-carbohydrate precursors. Glucose is the only energy source used by the brain (with the exception of ketone bodies during times of fasting), testes, erythrocytes, and kidney medulla. In mammals this process occurs in the liver and kidneys.
The pentose phosphate pathway is the major source for the NADPH required for anabolic processes. There are three distinct phases each of which has a distinct outcome. Depending on the needs of the organism the metabolites of that outcome can be fed into many other pathways. Gluconeogenesis is directly connected to the pentose phosphate pathway. As the need for glucose-6-phosphate (the beginning metabolite in the pentose phosphate pathway) increases so does the activity of gluconeogenesis.
