Transcript Cell signaling powerpoint active_transport_and_cell_signaling

Bellwork
► What
happens to an animal cell when it is in
a hypotonic solution?
► What happens to an animal cell when it is in
hypertonic solution? What about a plant
cell?
Review
► Onion
cell plasmolysis
More Review
Facilitated diffusion
Active transport and Cell
signaling
Active Transport
► Uses
energy to pump
molecules against their
concentration gradient
► Where do you think
they get this energy?
► ATP!!!
Electrical gradient
► Uneven
distribution of
ions gives it an
electrical gradient (neg
inside the cell, pos
outside the cell)
Cotransport
►A
solute flows with
another substance that
is diffusing across the
membrane
Endocytosis ► Phagocytosis
– Cell
eating
► Pinocytosis – cell
drinking
► Receptor-Mediated
Endocytosis
Check for understanding
► Compare
transport
and contrast active and passive
Cell signaling
Epinephrine – increases heart
rate, dilates blood vessels, dilates
pupils, elevates blood sugar
Assign one to each group member
► Communication
by direct contact
 Cell junctions
 Cell-cell recognition
► Local
signaling
 Paracrine
 Synaptic signaling
► Long
Distance
 Hormones
 Nervous system
What is the relevance of cell
signaling
► Another
Caffeine
example -
Three stages of cell signaling
Reception
► Reception
on the
plasma membrane (3
main types)
 G protein coupled
receptors
 Receptor tyrosine
kinase
 Ion channel receptors
► Intracellular
receptors
Intracellular
receptor
Reception in epinephrine
G protein coupled receptors
Transduction
► Signal
cascade – one
molecule activates the
next (usually by
phosphorylating it)
Transduction in epinephrine
► Response
Response
can be…
 a gene being
expressed (making a
protein
 Replication of the cell
 Activation of an enzyme
 Change in cell shape
 Programmed cell death
 And much more!
Response in
epinephrine
Cancer can be caused by an error
in signal molecules or
transduction pathways