Precancerous cells have: 

lost contact inhibition

less adherent and more rounded than normal cells

continue to divide

TLS Online TPP Program

#Id: 9080

#Unit 4. Cell Communication and Cell Signaling

Binding of acetylcholine triggers the opening of an associated K+ channel  in the plasma membrane via the Gβγ subunit of a Gi protein

TLS Online TPP Program

#Id: 9081

#Unit 4. Cell Communication and Cell Signaling

The increase in K+ permeability hyperpolarizes the membrane, which reduces the frequency of heart muscle contraction.

TLS Online TPP Program

#Id: 9082

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 9083

#Unit 4. Cell Communication and Cell Signaling

Cholera toxin, secreted by Vibrio cholerae in the intestine of an infected person, is a heterodimeric protein (AB). 

TLS Online TPP Program

#Id: 9084

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 9085

#Unit 4. Cell Communication and Cell Signaling

Subunit B recognizes and binds to specific gangliosides on the surface of intestinal epithelial cells and provides a route for subunit A to enter.