chapter seventeen Flashcards
____ ____ occurs when a signaling molecule is released from a signaling cell which binds to a receptor and transmits
Signal transduction
The signaling pathways produce changes in
Metabolism, ion transport, cell shape, transcription differentiation
4 types of cell signaling
Paracrine, neuronal, endocrine, and contact-dependent.
Notch-delta Signaling is what kind
Contact dependent
______ is expressed in a differentiating neuron, causes ___ inhibition of neighboring cells to prevent excess neuron differentiation
Delta, lateral
2 major classes of extracellular signaling
Cell-surface receptors andintracellular receptors
Receptors that perceive large hydrophilic ligands (cannot permeate membrane)
Cell-surface
Perceive hydrophobic ligands that permeate membranes
Intracellurar
A cell responds to a signal if they have the correct
Receptor
There can be different effectors for a single
Receptor
How many signals can impinge on a single cell
Many
the combination of ______ will determine the response to the signaling pathway
effectors
the signal transduction pathway can ____ and ____ the signal
spread and amplify
signal transduction pathways can modulate one another, _______ ______
integrating signals
______ can regulate effects to amplify or dampen the signaling
feeback
signaling molecules also need to be shut off to prevent ______
overstimulation
GTP binding proteins (monomeric G proteins) are a _____ _____
molecular switch
monomeric G proteins active and inactive states are regulated by ______ , _______ activating proteins, and ______ nucleotide exchange proteins
GTPase ; GTPase ; guanine
what are the 3 subunits of G-protein signaling
alpha, beta and gamma
binding a _____ causes a conformation change in the GPCR’s enabling it to bind a ________
ligand, G-protein
prior to binding a receptor, the G-protein is bound to ____ , after binding GDP is released and what binds?
GDP, GTP
G-proteins can induce enzyme activity, which produces _____ ____
second messengers
G protein stimulation of ______ ____ to produce cAMP
adenylyl cyclase
cAMP induces _____ _____ __
protein kinase A
PKA can induce ______ ______
gene expression
_____ signaling activates phospholipase C, which activates IP3 and diacylglycerol. IP3 binds Ca+ channel and releases Ca into cytoplasm
GPCR
NO gas is a ____
ligand
cells produce NO and bind receptors and stimulate effectors in smooth muscle which causes ____ and ____ _______ _____
relaxation and blood vessel opening
growth factor receptors are _____, which mediate important signaling processes
RTK’s
RTK’s (receptor tyrosine kinases; growth factor receptor) often induce _____
RAS
activated _____ induces a kinase cascated, leading to MAP kinase activation
RAS
what is RAS?
a monomeric G-protein (mutated in many cancers)
what does MAP kinase induce (it does this by changing protein activity and gene expression)
cell growth, cell survival, and differentiation
______ ____ can pass through the plasma membrane and bind intracellular receptors
steroid hormones
the unoccupied intracellular receptor is held in ______
cytoplasm
binding a hormone releases the intracellular receptor from the cytoplasm and it enters the _____ and activates ______
nucleus; transcription
