1. Concept 4: Analyzing Cell Communication
Chapter 11
Pg in Holtzclaw

2. Cell Communication You must know:
The three stages of cell communication: reception, transduction, and response (the signal transduction pathway!)
Applications/Examples!

3. Signal Transduction Pathway
Reception
Transduction
Response

4. Signal Transduction Pathway
Reception: Receptors undergo changes in shape due to an environmental stimulus

5. Signal Transduction Pathway
Transduction: Amplification of signal through a multistep pathway
Allows small signal to produce large cellular response
Uses protein kinases (phosphorylation cascade) and second messengers (Ca2+ and cAMP)

6. Signal Transduction Pathway
Response: Two ways response is accomplished:
Transcriptional Modification:
↑ or ↓ mRNA production (turning genes on/off)
Post-Translational Modification:
Activates existing enzyme molecules

7. Signal Transduction
Reception
Transduction
Response
Act Out!

8. Sample Questions
Describe the signal transduction pathway in terms of reception, transduction, and response.
Explain the two ways that responses can be accomplished
A hormone molecule ends up blocking RNA polymerase from attaching to a specific gene. Is this response transcriptional modification or post-translational?