Chapter 9

Describe one way in which endocrine', paracrine-, autocrine", and juxtacrine- signaling pathways are similar to one another and one way they differ from one another.

Explain how cells respond to external signal even when those signals cannot enter the cell.

Explain how signals can be specific in targeting only some cells, even if they are released into the bloodstream and come into contact with many cells.

List several positive types of responses a cell might have to a signaling molecule.

Compare and contrast cell-surface receptors and intracellular receptors in terms of their location, chemical properties of their signaling molecules, and types of responses mediated.

List several ways in which a signal may be amplified in an intracellular signaling pathway.

Describe ways in which the response of a cell to a signal can be terminated.