1 roentgen unit is a quantity of X ray that produces 2.083X109 ion pairs in one cubic centimeter of air at 0C and a pressure of 760 mm of mercury.

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

TLS Online TPP Program

#Id: 9331

#Unit 4. Cell Communication and Cell Signaling

In the dark, most transducin is localized to the outer segment, while most arrestin is found in other parts of the cell; in this condition, vision is most sensitive to very low light levels.