Bio 181, Fall 2005

Learning Objectives for Chapter 11, Cell Communication

Understand and be able to use the following terms:

signal transduction pathway	local regulator	paracrine	synaptic siganalling
neurotransmitter	endocrine	hormones	reception
transduction	response	ligand	receptor
g protein	g protein-linked receptor	tyrosine kinase	tyrosine kinase receptors
ligand gated ion channels	intracellular receptors	transcription factors	protein kinase
protein phosphatases	phosphorylation cascade	second messengers	cAMP
diacylglycerol	inositol trisphosphate	calcium

An Overview of Cell Signaling

1. Categorize chemical signals in terms of the proximity of the communicating cells.

2. Describe the three main stages of cell signaling.

Signal Reception and the Initiation of Transduction

3. Describe the nature of a ligand-receptor interaction and state how such interactions initiate a signal-transduction system.

4. Compare and contrast G-protein-linked receptors, tyrosine-kinase receptors, and ligand-gated ion channels.

5. Describe several advantages of using a multistep pathway in the transduction stage of cell signaling.

6. Explain what is usually passed along in a signal-transduction pathway.

7. Describe how phosphorylation propagates signal information.

8. Describe how cyclic AMP is formed and how it propagates signal information.

9. Describe how the cytoplasmic concentration of Ca²⁺ can be altered and how this increased pool of Ca²⁺ is involved with signal transduction

Cellular Responses to Signals

10. Describe how signal information is transduced into cellular responses in the cytoplasm and in the nucleus.

11. Describe how signal amplification is accomplished in target cells.

12. Describe how target cells discriminate among signals and how the same signal can elicit multiple cellular responses.