cell surface receptors
Cyclic AMP and calcium may be second messengers
They act as signals. All they need to be is identifiable.
Examples of the periodic signals include exponential and sinusoidal signal.
the signals are known as Action pottential. and the chemical substances or signal molecules are known as Neurotransmiters
Carbon
Mechanical signals of the ECM can alter the cytoskeleton, which can alter intracellular signaling.
"When adenylyl cyclase is activated, it catalyses the conversion of ATP to cyclic AMP, which leads to an increase in intracellular levels of cyclic AMP. Cyclic AMP functions as a "http://wiki.answers.com/../pathphys/endocrine/moaction/surface.html" to relay extracellular signals to intracellular effectors, particularly http://wiki.answers.com/pka.html. "
peptides(poly),gases,neurotransmitters,neuropeptides,steroid hormones ...etc.
Cytokines
Cyclic AMP and calcium may be second messengers
NO
DAC
yes its very simple to convert VGA signal into SVGA signal.
The brain
A Demodulator (MODEM)
HormonesNovaNet
Hormones