α-helix has positive band at 190nm and negative bands at 222nm and 208nm.

TLS Online TPP Program

#Id: 9091

#Unit 4. Cell Communication and Cell Signaling

The resultant efflux of NaCl triggers massive water loss through the intestine as cells respond to the ensuing osmotic imbalance causes severe dehydration and electrolyte loss.

TLS Online TPP Program

#Id: 9092

#Unit 4. Cell Communication and Cell Signaling

Pertussis toxin, produced by Bordetella pertussis, catalyzes ADP-ribosylation of the  subunit of Gαi, preventing GDP-GTP exchange and blocking inhibition of adenylyl cyclase.

TLS Online TPP Program

#Id: 9093

#Unit 4. Cell Communication and Cell Signaling

Ligand binding to GPCRs that activate Gαq, leading to activation of phospholipase C

TLS Online TPP Program

#Id: 9094

#Unit 4. Cell Communication and Cell Signaling

Phospholipase C cleaves a phospholipid known as PI(4,5) P2, generating two second messengers: 

diffusible IP3 and membrane-bound DAG

TLS Online TPP Program

#Id: 9095

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 9096

#Unit 4. Cell Communication and Cell Signaling

IP3 triggers the opening of IP3-gated Ca²+ channels in the ER and elevation of cytosolic free Ca²+.