In transduction, signals are relayed from
   receptors to target molecules, as in a cascade.
   Some  transduction  pathways  involve  small  molecules  called second
   messengers.
<P>
<BR><LI> cyclic AMP (cAMP)
<BR><LI> calcium
<P>
   Review:  <A ClAsS=ACT Href="http://media.pearsoncmg.com/bc/bc_campbell_biology_7/media/activities/load.html?11&amp;C" oNClick="popact('http://media.pearsoncmg.com/bc/bc_campbell_biology_7/media/activities/load.html?11&amp;C');txtcolor('transduction5','gray');return false;" Id=transduction5><iMg sRc="/images/tutorial.gif" aLt='' boRDer=0></A>