kininogen and kallikrein, can be brought about 

In vitro by exposing the blood to glass

In vivo by collagen fibers underlying the endothelium

TLS Online TPP Program

#Id: 9325

#Unit 4. Cell Communication and Cell Signaling

Each opsin molecule has multiple principal serine and threonine phosphorylation sites on its cytosol-facing C-terminal segment.

TLS Online TPP Program

#Id: 9326

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 9327

#Unit 4. Cell Communication and Cell Signaling

The binding of arrestin to rhodopsin speeds up the inactivation process.

TLS Online TPP Program

#Id: 9328

#Unit 4. Cell Communication and Cell Signaling

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: 9329

#Unit 4. Cell Communication and Cell Signaling

The entire process of rhodopsin phosphorylation and its inactivation by arrestin is fast completed within 50ms. 

TLS Online TPP Program

#Id: 9330

#Unit 4. Cell Communication and Cell Signaling

Phosphorylated rhodopsin is restored to its light-sensitive state (R) during dark adaptation by a specific rhodopsin phosphatase