CHEM-C 483 Study Guide - Midterm Guide: Adipose Tissue, Oxidative Phosphorylation, Acetyl Group
Document Summary
Glycolysis: the conversion of the six-carbon glucose to the three-carbon pyruvate which occurs in ten steps. Gluconeogenesis: the synthesis of glucose from smaller compounds. Glucose + 2 nad+ + 2 adp + 2 pi 2 pyruvate + 2 nadh + 2 atp. The first phase (steps 1-5) the hexose is phosphorylated and cleaved in half. In the second phase (steps 6-10) the three carbon molecules are converted to pyruvate. The first phase is the energy investment phase while the second is the energy payoff phase. We learned that the hexokinase active site closes around its substrates so that a phosphoryl group is efficiently transferred from atp to glucose. The magnitude of the free energy change causes the reaction to proceed in only one direction (since 16. 7 kj mol-1). It makes sense that this is a near-equilibrium reaction since in vivo the change in free energy is near zero which indicates that the reaction operates close to equilibrium.
