Chapter 16 04/24/2015
General principles of cell signaling
Information can come in a variety of forms and communication
frequently involves converting the signal that carry that information from one
form to an
...
Chapter 16 04/24/2015
General principles of cell signaling
Information can come in a variety of forms and communication
frequently involves converting the signal that carry that information from one
form to another = the process is called signal transduction.
In typical communication between cells, the signaling cell produces a
type of extracellular signal that is detected by the target cell.
Most animals can send and receive signals and therefore can act as
both signaling cells and target cells.
Target cells possess proteins called receptors that recognize and
respond specifically to the signal molecule. Signal transduction begins when
the receptor on the target cell receives an incoming extracellular signal and
converts it to the intracellular signaling molecules that alter cell behavior.
Cell signaling- signal reception and transduction.
Signals can act over a long or short range:
Signal molecules can be proteins, peptides, amino acids, nucleotides,
steroids, fatty acid derivatives, and dissolved gases.
1. The most “public” style of cell to cell communication involves
broadcasting the signal throughout the whole body by secreting into an
animals bloodstream or a plants sap. Extracellular signal molecules used in
this way are called hormones.
The cells that produce hormones are called endocrine cells.
Pancreas- is a endocrine gland that produces several hormones- ex.
Insulin- which regulates glucose uptake in cells all over the body.
2. Less public is a process known as paracrine signaling- rather than
entering the bloodstream, the signal molecules diffuse locally through the
extracellular fluid, remaining in the neighborhood of the cell that secretes
th
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