Lecture 17

Question 1

____- are the largest family of cell surface receptors

Answer 1

GPCRs

Question 2

there are over ____ GPCRs in humans

Answer 2

800

Question 3

all GPCRs have a common structure with __ transmembrane spans across the lipid bilayer

Answer 3

7

Question 4

what are some examples of GPCRs? (GADH)

Answer 4

glucagon
adrenaline
dopamine
histamine

Question 5

g proteins act as a molecular ____

Answer 5

switch

Question 6

GDP is removed and replaced with ___. this process is triggered by the activation of _____ which is known to be a GEF (_______)

Answer 6

GTP
GPCR
Guanine nucleotide exchange factor

Question 7

in the _____ state, the G protein consists of a _____ complex located in the _____

Answer 7

inactivated
trimeric
plasma membrane

Question 8

in the activated state, the trimeric G protein complex ______

Answer 8

dissociates

Question 9

G proteins that interact with GCPRs comprise of three subunits - _________

Answer 9

alpha, beta, y

Question 10

G proteins are activated when bound to _____

Answer 10

GTP

Question 11

G proteins hydrolyze _____ to ____

Answer 11

GTP
GDP

Question 12

the interaction of G proteins with ion channels causes an _________________

Answer 12

immediate change in cell behaviour

Question 13

Enzyme activation leads to the production of _____________ which act as _____________

Answer 13

intracellular signalling molecules
second messengers

Question 14

a second messenger is a rapidly produced ______ signalling molecule that activates ________

Answer 14

diffusible
effector proteins

Question 15

like other molecular switches, second messengers will also be rapidly ______ again

Answer 15

inactivated

Question 16

amplification results in what?

Answer 16

strong activation in very short time

Question 17

what is a way for termination of signalling? (to do with something at the cell surface)

Answer 17

once the receptor is not at the cell surface anymore, signalling stops

Question 18

cyclic AMP is produced from _____ by _____-

Answer 18

ATP
adnylyl cyclase

Question 19

cAMP is rapidly inactivated by a ______

Answer 19

phosphodiesterase

Question 20

what is the process of PKA and gene transcription?

activation of PKA in _______
translocation to ______
_______ of transcription factors
increased/suppressed _______ of target genes

Answer 20

cytosol
nucleus
phosphorylation
transcription

Question 21

via _______, one ligand molecule binding gives rise to __________

Answer 21

catalysis
many new intracellular molecules

Question 22

phospholipase C cleaves ____ into the second messengers IP__ and ____

Answer 22

PIP2
3
DAG