BS 161 Exam 3 UPDATED Questions and
CORRECT Answers
Ligand - CORRECT ANSWER - signaling molecule that binds to a specific receptor
protein, initiating signal transduction in cells
Membrane receptor - CORRECT ANSWER - A highly specific cell-surface receptor
embedded in a cell membrane that responds only to a specific messenger molecule
intracellular receptor - CORRECT ANSWER - regulate gene transcription
hydrophobic molecules
signal transduction pathway - CORRECT ANSWER - interaction of membrane receptor
and intracellular receptor.
converts the information in the external signal into a cellular response
chemically gated ion channel - CORRECT ANSWER - channel-linked receptors that open
to let a specific ion pass in response to a ligand
type of membrane receptor
enzymatic receptor - CORRECT ANSWER - receptor is an enzyme that is activated by the
ligand
Almost all are protein kinases. type of membrane receptor
G-protein - CORRECT ANSWER - binds to GTP.
ligand binds to the receptor, activating it, which activates the G protein, which in turn activates
the effector protein
provides link between receptor that receives signals and effector proteins that produce cellular
responses.
, functions as switch that is turned on by the receptor. In its "on" state, G protein activates effector
proteins to cause a cellular response
A protein made up of three different subunits (heterotrimeric) named alpha, beta and gamma.
The alpha subunit binds the nucleotide GTP and can hydrolyze the GTP to GDP or make GDP --
> GTP
on state/active state = bound to GTP
off state/inactive state = bound to GDPand Pi
G-protein coupled receptor - CORRECT ANSWER - bind to ligands outside the cell and
to G proteins inside the cell.
type of membrane receptor
G protein (bound to GTP) assists in transmitting the signal from receptor to enzyme (effector).
ligand binds to GPCR and causes a conformational change, which activates the GPCR to
exchange GDP for GTP
GTP - CORRECT ANSWER - guanosine triphosphate
guanine, ribose, and three phosphate groups
binds to G-proteins
Heterotrimeric - CORRECT ANSWER - G protein-coupled receptors act through
heterotrimeric G protein that links the receptor to an effector protein.
alpha, beta, gamma regions of G protein. Alpha region binds to GTP to make GDP
Adenylate cyclase - CORRECT ANSWER - effector protein that produces the second
messenger cAMP
produce cAMP and IP3 plus DAG
Produces cAMP
cAMP binds to and activates the enzyme protein kinase A (PKA)
PKA adds phosphates to specific proteins
second messenger
CORRECT Answers
Ligand - CORRECT ANSWER - signaling molecule that binds to a specific receptor
protein, initiating signal transduction in cells
Membrane receptor - CORRECT ANSWER - A highly specific cell-surface receptor
embedded in a cell membrane that responds only to a specific messenger molecule
intracellular receptor - CORRECT ANSWER - regulate gene transcription
hydrophobic molecules
signal transduction pathway - CORRECT ANSWER - interaction of membrane receptor
and intracellular receptor.
converts the information in the external signal into a cellular response
chemically gated ion channel - CORRECT ANSWER - channel-linked receptors that open
to let a specific ion pass in response to a ligand
type of membrane receptor
enzymatic receptor - CORRECT ANSWER - receptor is an enzyme that is activated by the
ligand
Almost all are protein kinases. type of membrane receptor
G-protein - CORRECT ANSWER - binds to GTP.
ligand binds to the receptor, activating it, which activates the G protein, which in turn activates
the effector protein
provides link between receptor that receives signals and effector proteins that produce cellular
responses.
, functions as switch that is turned on by the receptor. In its "on" state, G protein activates effector
proteins to cause a cellular response
A protein made up of three different subunits (heterotrimeric) named alpha, beta and gamma.
The alpha subunit binds the nucleotide GTP and can hydrolyze the GTP to GDP or make GDP --
> GTP
on state/active state = bound to GTP
off state/inactive state = bound to GDPand Pi
G-protein coupled receptor - CORRECT ANSWER - bind to ligands outside the cell and
to G proteins inside the cell.
type of membrane receptor
G protein (bound to GTP) assists in transmitting the signal from receptor to enzyme (effector).
ligand binds to GPCR and causes a conformational change, which activates the GPCR to
exchange GDP for GTP
GTP - CORRECT ANSWER - guanosine triphosphate
guanine, ribose, and three phosphate groups
binds to G-proteins
Heterotrimeric - CORRECT ANSWER - G protein-coupled receptors act through
heterotrimeric G protein that links the receptor to an effector protein.
alpha, beta, gamma regions of G protein. Alpha region binds to GTP to make GDP
Adenylate cyclase - CORRECT ANSWER - effector protein that produces the second
messenger cAMP
produce cAMP and IP3 plus DAG
Produces cAMP
cAMP binds to and activates the enzyme protein kinase A (PKA)
PKA adds phosphates to specific proteins
second messenger
