Secondary Messengers

Secondary messengers are small molecules or ions within the cell that relay signals from receptor proteins on the cell surface to internal targets, leading to a cellular response. They’re called “secondary” because they act after the “primary” messenger—an external signal like a hormone or growth factor—binds to a receptor to start the signaling process.

Topics

  • AP
  • AP Biology
  • AP Bio
  • next generation science standards
  • NGSS
  • Fight-or-flight response
  • cell signaling
  • adrenaline
  • adrenergic receptor
  • signaling molecule
  • signaling cascade
  • phosphate
  • phosphorylation cascade
  • phosphorylation
  • kinase
  • PKA
  • phosphodiesterase
  • second messenger
  • secondary messenger
  • cyclic AMP
  • cAMP
  • cGMP
  • IP3
  • DAG
  • NO
  • calcium ions
  • Ca2+
  • phosphatase
  • signal transduction
  • cell division
  • signal amplification
  • signal reception
  • reception
  • transduction
  • cellular response
  • protein structure
  • conformational change
  • protein shape
  • structural change
  • activation
  • signal interruption
  • signal termination
  • signal relay