There are about 90 million rod cells in the human retina, and each contains about 4x107 molecules of rhodopsin that are very densely packed in the membrane disks.

TLS Online TPP Program

#Id: 6544

#Unit 7. System Physiology – Animal

In GSV, much of the GLUT4 is tethered to the Golgi matrix, a network of coiled-coil proteins surrounding the Golgi complex,  by a TUG protein

TLS Online TPP Program

#Id: 6545

#Unit 7. System Physiology – Animal

Binding of insulin to the insulin receptor leads to activation of a protease that cleaves the TUG protein, releasing GLUT4-containing vesicles, which move along microtubules

TLS Online TPP Program

#Id: 6546

#Unit 7. System Physiology – Animal

Insulin also activates PKB which phosphorylates the Rab GAP protein AS160

TLS Online TPP Program

#Id: 6547

#Unit 7. System Physiology – Animal

Rab proteins in their active GTP-bound states, allow the GLUT4 storage vesicles to move along microtubules to the cell surface

TLS Online TPP Program

#Id: 6548

#Unit 7. System Physiology – Animal

Fusion of GSVs with the plasma membrane catalyzed by the exocyst & monomeric GTP-binding protein, RALA

TLS Online TPP Program

#Id: 6549

#Unit 7. System Physiology – Animal

Plasma membrane GLUT4 allows the cell to incorporate glucose from the ECF