2. Signal Pathways lead to the synthesis of
enzymes or proteins, not to activity.
Three stages of responses:
Signal Reception.
Signal Transduction.
Signal Response.
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3. Enzyme amplification signal.
Each step gradually increase as steps get
higher.
Amplification effect stems.
The result of amplification.
5. Each cell has variety of responses to a signal.
Different Proteins.
Cross paths.
Different Receptors.
6. These pathways used to be thought
independent, and linear ones.
However, we now realize that things aren’t so
simple; therefore, we also now have a better
understanding of the processes of cellular
communication.
(See figure 11.5)
7. Scaffold proteins are crucial regulators of many key signaling
pathways.
They interact or bind with multiple members of a signaling
pathway.
They regulate signal transduction and help localize pathway
components to specific areas of the cell (ex. Plasma membrane,
cytoplasm, etc..)
Example: Researchers are now finding scaffolding proteins that
permanently hold together networks of signaling-pathway
proteins at synapses.
Why is this important?
This “hardwiring”, per say, enhances the speed and accuracy of
signal transfer between cells.
*RECALL that when a signal is relayed along a pathway, only
certain information is passed on.
8. The time to remain alert is a short time.
The there must be a reversibility to the changes
that signals produce.
When signal molecules leave the receptor it
reverts to its inactive form.