Arrestin binds tightly to rhodopsin only when rhodopsin kinase has phosphorylated a sufficient number of C-terminal serines and threonines.

TLS Online TPP Program

#Id: 324

#Unit 1. Molecules and their Interaction Relevant to Biology

TLS Online TPP Program

#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. 

TLS Online TPP Program

#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

TLS Online TPP Program

#Id: 329

#Unit 1. Molecules and their Interaction Relevant to Biology

FBPase-1 is a gluconeogenic enzyme

TLS Online TPP Program

#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

TLS Online TPP Program

#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.