Chapter 11 - Cell Signaling

Cell Communication

• Direct contact (Fig. 11.4)   * Junctions   * Surface proteins
• Fig. 11.5   * Local regulator: paracrine   * Hormones: long distance regulation through blood
• 3 stages (Fig. 11.6)   * Reception of signal   * Transduction of signal within the cell (phosphorylation)   * Response to the signal (final outcomes)   * Ex: epinephrine/cell signal

Types of Receptors

• G protein-coupled receptors (GPCR)
• Tyrosine kinase receptors
• Ion channel receptors
• Intracellular receptors

Apoptosis

• Programmed cell death
• Occurs when cells are:   * Infected   * Damaged   * At the end of their functional life span
• Chop up DNA and package cellular contents into vesicles
• Protects neighboring cells
• Normal part of development of hands and feet in humans (and paws in other animals)

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