NAME__________________________________________DATE_______________
Chapter 11 Key Concepts
Cell Communication
Guided Reading
Concept 11.1: External signals are converted to responses within the cell
1. What is a signal transduction pathway?
2. Explain how yeast (which are unicellular and typically reproduce asexually by budding) actually mate with other
yeast cells to produce genetically diverse cells.
3. Explain quorum sensing.
4. Review intercellular junctions in animal cells and plasmodesmata from chapter 6.
5. Explain cell-cell recognition and give an example of when it is used.
6. Communication done by cells over a short distance is done by local regulators. Describe the types of local
regulators below:
a. Growth factors
b. Paracrine signaling
c. Synaptic signaling
7. Long distance signaling by plants and animals can be done by hormones. Describe an example of how plants use
hormones for signaling as well as the use of hormones by animals.
8. Complete the table below by summarizing the three stages of cell signaling.
Summary of Reception -
Summary of Transduction-
Summary of Response-
Concept 11.2: Reception: A signaling molecule binds to a receptor protein causing it to change shape
9. Explain the term ligand.
10. There are three main types of membrane receptors. Use the table below to summarize these receptors.
Membrane Receptor
Description of signaling process
Examples of their uses in living organisms
G Protein –
Coupled Receptors
Receptor Tyrosine Kinases
Ion Channel Receptors
11. Explain how intracellular receptor proteins function using testosterone as the example.
Concept 11.3: Transduction: Cascades of
molecular interactions relay signals from
receptors to target molecules in the cell
12. Explain the role of the following two
categories of enzymes in the process
of transduction.
13. Explain the role of a second
messenger during transduction.
14. What is the immediate effect of
cAMP formation?
15. What are some examples of cellular
responses resulting from the
formation of second messengers
such as cAMP or cGMP?
Concept 11.4: Response: Cell signaling
leads to regulation of transcription or
cytoplasmic activities
16. Cellular activities are regulated by
signal transduction pathways. When
cell signaling causes a response in
the nucleus, what normally
happens? When cell signaling
causes a response in the cytoplasm,
what normally happens?
17. How do enzyme cascades amplify the cells response to a signal?
18. Multistep cascades provide multiple opportunities for coordination and regulation. Why do different cells exhibit
different cellular responses to signals?
19. What is the role of scaffolding proteins in signal transduction?
20. How are signals terminated?
Concept 11.5: Apoptosis (programmed cell death) integrates multiple cell signaling pathways.
21. Explain what apoptosis is and what signals can trigger them (use at least two specific examples).
Testing Your Knowledge -Self Quiz Answers
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Write About It –
1. This chapter is incredibly difficult and the material is almost entirely new. In order to better understand some of things
mentioned in the chapter, take a couple minutes and research epinephrine and diabetes. Explain the relationship
between these two things using terminology from this chapter.
2. Research and briefly describe how cAMP regulates gene expression in bacteria.