When the initial removal involves lyase action, the endonuclease APE1 instead recruits DNA polymerase b to replace a single nucleotide. The nick is then sealed by the ligase XRCC1/ligase-3. This is called the short-patch pathway.

#Id: 326

#Unit 1. Molecules and their Interaction Relevant to Biology

When blood glucose rises above 5 mM, hexokinase IV activity increases, but hexokinase I is already operating near Vmax and cannot respond to an increase in glucose concentration. 

#Id: 327

#Unit 1. Molecules and their Interaction Relevant to Biology

Hexokinase IV is subject to inhibition by the reversible binding of a regulatory protein specific to liver

#Id: 329

#Unit 1. Molecules and their Interaction Relevant to Biology

#Id: 333

#Unit 1. Molecules and their Interaction Relevant to Biology

Fructose 2,6-bisphosphate binds to its allosteric site on PFK-1, it increases the enzyme’s affinity for its substrate fructose 6-phosphate and reduces its affinity for the allosteric inhibitors ATP and citrate

#Id: 335

#Unit 1. Molecules and their Interaction Relevant to Biology

Glucagon lowers the cellular level of fructose 2,6 bisphosphate, inhibiting glycolysis and stimulating gluconeogenesis.

#Id: 342

#Unit 1. Molecules and their Interaction Relevant to Biology

Accumulation of alanine, which can be synthesized from pyruvate in one step, allosterically inhibits pyruvate kinase, slowing the production of pyruvate by glycolysis