Cell Communication

Concept 11.1 External signals are converted into responses within the cell


Evolution of Cell Signaling

Local and Long-Distance Signaling

  • Cells in a multicellular organism communicate through chemical messengers targeted for cells that may or may not be adjacent
  • Cells may communicate directly
    • plant cells can connect cytoplasm’s of adjacent cells
  • animal cells can communicate directly between membrane-bound cell surface molecules
  • Important for embryonic development and immune response
  • Cell junctions- Both animals and plants have these, allow molecules to pass readily between adjacent cells w/o crossing plasma membranes.
  • Cell-cell recognition- Two cells in an animal may communicate by interaction between molecules protruding from their surfaces.
  • Sometimes messenger cells are secreted by signaling cell.
  • Some travel short distances, local regulators influence cells in vicinity

The Three Stages of Cell Signaling

Concept 11.2 Reception: A signal molecule binds to a receptor protein, causing it to change shape

Intracellular Receptors
Receptors in the Plasma Membrane

Concept 11.3 Transduction: Cascades of molecular interactions relay signals from receptors to target molecules in the cell

Signal Transduction Pathways
Protein Phosphorylation and Dephosphorylation
Small Molecules and Ions as Second Messengers

Concept 11.4 Response: Cell signaling leads to regulation of cytoplasmic activities or transcription

Cytoplasmic and Nuclear Responses
Fine-Tuning of the Response

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License