Biochemistry 2280A Lecture Notes - Pentose, Gluconeogenesis, Adipocyte
Document Summary
When blood glucose is high, the pancreas secretes insulin. Initially, the flux through glycolysis and citric acid cycle is high due to the high concentration of substrate (glucose derivatives) and insulin present. Eventually, the concentration of atp and other energy indicators of the cell increase, inhibiting glycolysis and the citric acid cycle. In this state, fatty acid synthesis, the pentose phosphate pathway and biosynthesis are favoured. When blood glucose is low, the pancreas secretes glucagon. Glucose is produced from glycogen and gluconeogenesis (from amino acids obtained from protein degradation). Adipocytes release fatty acids from storage and eventually, the liver produces ketone bodies. All of these actions occur simultaneously when the body is in the unfed state. Biosynthesis is not favoured as the focus of tissues is on energy conservation. The liver will always pump out some glucose (packaged correctly) in order to sustain the brain.