Ch. 14: Cell Signaling Online Quiz (MC) Flashcards
G protein-coupled receptors generally contain ___ membrane-spanning a helices.
7
PKA binds a total of four molecules, two molecules on each of the two ___ subunits.
regulatory (R)
Cyclic AMP (cAMP) is synthesized from ATP by the action of ___ ___.
adenylyl cyclase
The α subunit ___ ___ becomes deactivated when the hormone dissociates from the receptor.
DOES NOT
The ___ signaling pathway allows for direct cell–cell signaling by transmembrane proteins.
Notch
Most of the effects of cyclic AMP (cAMP) in the cell are mediated by ___ ___ ___.
protein kinase A (PKA)
Q: Receptor protein-tyrosine kinases represent critical molecules involved in growth and differentiation though phosphorylation of target substrates on tyrosine residues. Which of the following is not a common structural feature of all receptor protein-tyrosine kinases?
A: ___ ___ ___.
A single polypeptide
The term “paracrine signaling” refers to:
Signaling between cells located ___ to each other.
close
___ are transmembrane proteins that connect the extracellular matrix to the cytoskeleton.
integrins
In unstimulated cells, NF-κB proteins are maintained in an inactive state in the cytosol by interactions with ___.
lkB
___ ___ is a hormone NOT synthesized from cholesterol.
retinoic acid
Insulin released by β cells in the pancreas, mediating the effect of glucose uptake by muscle cells, is an example of ___ signaling.
endocrine signaling
The MEK kinase (MAP kinase/ERK kinase) is unusual in that it is a dual-specificity kinase, having the ability to phosphorylate both ___ and ___.
tyrosine and threonine
