Overview of Cell Communication

Cell Communication

Essential for cell function and survival.

Direct Contact

Communication through cell junctions between adjacent cells.

Gap Junctions

Animal cell structures allowing direct communication.

Plasmodesmata

Plant cell structures facilitating direct contact.

Local Regulators

Chemical messages released for nearby cell signaling.

Paracrine Signaling

Local regulators act on adjacent cells.

Synaptic Signaling

Neurons release neurotransmitters across synaptic cleft.

Long-Distance Signaling

Hormones travel through circulatory or vascular systems.

Endocrine Signaling

Hormones released into blood for distant effects.

Insulin

Hormone regulating glucose, released by pancreas.

Cell Signaling Stages

Includes reception, transduction, and response.

Reception

Ligand binds to receptor in target cell.

Transduction

Extracellular signal converted to intracellular signal.

Response

Cellular process altered by final signaling molecule.

Receptor

Macromolecule binding to signal molecules.

G Protein-Coupled Receptors (GPCRs)

Largest category of cell surface receptors.

Ligand-Gated Ion Channels

Receptors that open/close to regulate ion flow.

Second Messengers

Small molecules amplifying the signal inside cells.

Cyclic AMP (cAMP)

Common second messenger in signaling pathways.

Phosphorylation

Addition of phosphate group to regulate proteins.

Dephosphorylation

Removal of phosphate group, shutting off pathways.

Signal Transduction Pathway

Sequence of molecular events relaying signals.

Mutations in Signaling Pathways

Altered transduction due to receptor protein changes.

Nervous System Signaling

Involves synaptic signaling and neurotransmitter release.

Cellular Response Examples

Altered permeability, metabolic changes, gene regulation.

Target Cell

Cell that responds to signaling molecules.

Extracellular Fluid

Fluid outside cells where local regulators travel.

Antigen Presenting Cells (APCs)

Immune cells communicating via direct contact.