COP1 is found in the nucleus in the dark and in the cytoplasm in the light. COP1 movement into the nucleus in the dark requires the COP9 signalosome (CSN) complex

TLS Online TPP Program

#Id: 6528

#Unit 7. System Physiology – Animal

Insulin, 

synthesized and secreted 

by the β cells

TLS Online TPP Program

#Id: 6529

#Unit 7. System Physiology – Animal

Insulin has an AB heterodimer structure with 

One intrachain (A6-A11) 

Two interchain disulfide bridges (A7-B7 and A20-B19)

TLS Online TPP Program

#Id: 6530

#Unit 7. System Physiology – Animal

TLS Online TPP Program

#Id: 6531

#Unit 7. System Physiology – Animal

Insulin secretion by the pancreatic beta cells in response to increased blood glucose concentration

TLS Online TPP Program

#Id: 6532

#Unit 7. System Physiology – Animal

The beta cells have a large number of glucose transporters that permit a rate of glucose influx that is proportional to the blood concentration in the physiological range

TLS Online TPP Program

#Id: 6533

#Unit 7. System Physiology – Animal

The entry of glucose into pancreatic β cells is mediated by the GLUT2 glucose transporter Because the Km for glucose of GLUT2 is 20 mM, a rise in extracellular glucose from 5 mM, causes a proportional increase in the rate of glucose entry