16. Figure 11.5
Local signaling Long-distance signaling
Target cell
Secreting
cell
Secretory
vesicle
Local regulator
diffuses through
extracellular fluid.
(a) Paracrine signaling (b) Synaptic signaling
Electrical signal
along nerve cell
triggers release of
neurotransmitter.
Neurotransmitter
diffuses across
synapse.
Target cell
is stimulated.
Endocrine cell
Blood
vessel
Hormone travels
in bloodstream.
Target cell
specifically
binds
hormone.
(c) Endocrine (hormonal) signaling
17. Figure 11.5a
Local signaling
Target cell
Secreting
cell
Secretory
vesicle
Local regulator
diffuses through
extracellular fluid.
(a) Paracrine signaling (b) Synaptic signaling
Electrical signal
along nerve cell
triggers release of
neurotransmitter.
Neurotransmitter
diffuses across
synapse.
Target cell
is stimulated.
27. Figure 11.7b
G protein-coupled
receptor
21
3 4
Plasma
membrane
G protein
(inactive)
CYTOPLASM
Enzyme
Activated
receptor
Signaling
molecule
Inactive
enzyme
Activated
enzyme
Cellular response
GDP
GTP
GDP
GTP
GTP
P i
GDP
GDP
51. Figure 11.12
G protein
First messenger
(signaling molecule
such as epinephrine)
G protein-coupled
receptor
Adenylyl
cyclase
Second
messenger
Cellular responses
Protein
kinase A
GTP
ATP
cAMP
62. Figure 11.16
Reception
Transduction
Response
Binding of epinephrine to G protein-coupled receptor (1 molecule)
Inactive G protein
Active G protein (102
molecules)
Inactive adenylyl cyclase
Active adenylyl cyclase (102
)
ATP
Cyclic AMP (104
)
Inactive protein kinase A
Active protein kinase A (104
)
Inactive phosphorylase kinase
Active phosphorylase kinase (105
)
Inactive glycogen phosphorylase
Active glycogen phosphorylase (106
)
Glycogen
Glucose 1-phosphate
(108
molecules)
64. Wild type (with shmoos) ∆Fus3 ∆formin
Mating
factor
activates
receptor.
Mating
factor G protein-coupled
receptor
Shmoo projection
forming
Formin
G protein binds GTP
and becomes activated.
2
1
3
4
5
P
P
P
P
ForminFormin
Fus3
Fus3Fus3
GDP
GTP
Phosphory-
lation
cascade
Microfilament
Actin
subunit
Phosphorylation cascade
activates Fus3, which moves
to plasma membrane.
Fus3 phos-
phorylates
formin,
activating it.
Formin initiates growth of
microfilaments that form
the shmoo projections.
RESULTS
CONCLUSION
Figure 11.17
71. Figure 11.18
Signaling
molecule
Receptor
Relay
molecules
Response 1
Cell A. Pathway leads
to a single response.
Response 2 Response 3 Response 4 Response 5
Activation
or inhibition
Cell B. Pathway branches,
leading to two responses.
Cell C. Cross-talk occurs
between two pathways.
Cell D. Different receptor
leads to a different
response.
73. Response 4 Response 5
Activation
or inhibition
Cell C. Cross-talk occurs
between two pathways.
Cell D. Different receptor
leads to a different
response.
Figure 11.18b
80. Figure 11.21
Mitochondrion
Ced-9
protein (active)
inhibits Ced-4
activity
Receptor
for death-
signaling
molecule
Ced-4 Ced-3
Inactive proteins
(a) No death signal
Death-
signaling
molecule
Ced-9
(inactive)
Cell
forms
blebs
Active
Ced-4
Active
Ced-3
Other
proteases
NucleasesActivation
cascade
(b) Death signal