The α-amanitin binding site is beneath a “bridge helix” extending across the cleft between the two largest pol II subunits which are

TLS Online TPP Program

#Question id: 1119

#Unit 4. Cell Communication and Cell Signaling

Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because they:

TLS Online TPP Program

#Question id: 1120

#Unit 4. Cell Communication and Cell Signaling

A mutation that knocks out the GTPase activity of a G protein would have what effect on a cell?

TLS Online TPP Program

#Question id: 1121

#Unit 4. Cell Communication and Cell Signaling

Which of the following provides the best evidence that cell-signaling pathways evolved early in the history of life?

TLS Online TPP Program

#Question id: 1122

#Unit 4. Cell Communication and Cell Signaling

In endocrine signaling, the signaling molecule.

TLS Online TPP Program

#Question id: 1123

#Unit 4. Cell Communication and Cell Signaling

Epinephrine can be what kind of signaling molecule?

a. autocrine      b. direct contact  c. endocrine d. paracrine

TLS Online TPP Program

#Question id: 1124

#Unit 4. Cell Communication and Cell Signaling

Which of the following is (are) intracellular second messengers?

a. Ca2+                        b. cAMP          c. epinephrine             

d. protein kinase A      e. protein kinase C