Cell Signaling
HOW CELLS COMMUNICATE
Learning Objectives
 How do cells communicate long and short distances?
 What are the 3 stages of cell signaling?
 What is involved in each of the 3 stages of cell
signaling?
Cell Communication Video
HTTP://WWW.BOZEMANSCIENCE.COM/037CELL-COMMUNICATION
Signaling
Local Regulators
 Direct Contact


Cell junctions
Cell-cell recognition
 Paracrine

Growth factors cause cells to
grow and multiply
 Synaptic


Nervous system
Electrical signal triggers
chemical signal –
neurotransmitters
Signaling
Long-Distance
 Hormones
 “endocrine signaling”
 Cells release hormone
molecules into blood
vessels where they travel
to other parts of the body
 Plant hormones can travel
through cells, or through
air as a gas
 Vary a lot in size & type:
ethylene vs. insulin
Three Stages
of Cell
Signaling
A Preview…
 1. Reception
 A chemical signal is “detected” when it
binds to a receptor protein on the cell’s
surface or inside the cell.
Three Stages
of Cell
Signaling
A Preview…
 2. Transduction
 The receptor protein changes in
response to the signal and initiates the
process of converting the signal to a
form that can bring about the response.
 Can be a single step or a sequence of
changes in multiple molecules (“signal
transduction pathway”)
Three Stages
of Cell
Signaling
A Preview…
 3. Response
 Any cellular activity
 Must happen in the right cells, at the
right time, and in coordination with
other cells of the organism
Signal Transduction Video
HTTP://WWW.BOZEMANSCIENCE.COM/038SIGNAL-TRANSDUCTION-PATHWAYS