What role does a transcription factor play in a signal transduction pathway?

What role does a transcription factor play in a signal transduction pathway?

A. By binding a plasma membrane receptor it initiates a cascade
B. It relays a signal from the cytoplasm to the plasma membrane
C. It activates relay proteins
D. By binding to DNA it triggers the transcription of a specific gene
E. It is a plasma membrane protein that binds signal molecules

Answer: D

A toxin that inhibits the production of GTP would interfere with the function of a signal transduction pathway that is initiated by the binding of a signal molecule to _____ receptors.

A toxin that inhibits the production of GTP would interfere with the function of a signal transduction pathway that is initiated by the binding of a signal molecule to _____ receptors.

A- intracellular

B-steroid

C- ion-channel

D- G-protein-linked

E- receptor tyrosine kinase






Answer: D

Lipid-soluble signal molecules, such as testosterone, cross the membranes of all cells but affect only target cells because

Lipid-soluble signal molecules, such as testosterone, cross the membranes of all cells but affect only target cells because 

A)only target cells retain the appropriate DNA segments.
B) intracellular receptors are present only in target cells.
C) most cells lack the Y chromosome required.
D) only target cells possess the cytosolic enzymes that transduce the testosterone.
E) only in target cells is testosterone able to initiate the phosphorylation cascade leading to activated transcription factor.

Answer: B

Protein phosphorylation is commonly involved with all of the following except

Protein phosphorylation is commonly involved with all of the following except

A) regulation of transcription by extracellular signal molecules.
B) enzyme activation.
C) activation of G protein-coupled receptors.
D) activation of receptor tyrosine kinases.
E) activation of protein kinase molecules.

Answer: C