Ch 20 Cell Communication & Junctions

Flashcards covering key concepts related to cell communication and junctions as discussed in the lecture.

Cell Signaling

The process by which cells communicate through chemical signals.

Signaling Cell

The cell that releases the chemical signal.

Target Cell

The cell that receives the chemical signal.

Receptors

Proteins that bind to signaling molecules and cause a response.

Ligands

Signaling molecules that specifically bind to receptors.

Autocrine Signaling

A type of signaling where a cell targets itself.

Paracrine Signaling

A type of signaling where a cell signals to nearby cells.

Endocrine Signaling

A type of signaling where a cell targets another cell through the bloodstream.

Direct Signaling

A type of signaling where cells are directly attached to each other.

Gap Junction

Water-filled channels that allow small signaling molecules to diffuse between two connected cells.

Internal Receptors

Receptors found in the cytoplasm of target cells that are involved in gene expression.

Cell-Surface Receptors

Integral proteins that bind to external signaling molecules and perform signal transduction.

Signal Transduction

The conversion of an extracellular signal into an intracellular signal.

Lipid-Soluble Ligands

Ligands that bind to internal receptors in the cytoplasm and can cross the plasma membrane.

Lipid-Insoluble Ligands

Ligands that bind to cell-surface receptors and cannot cross the plasma membrane.

Termination of Signaling Pathways

The process of degrading the ligand or removing it to stop signaling.

Tight Junctions

Watertight seals between two cells.

Desmosomes

Intracellular junctions that act like 'spot welds' between adjacent cells.

Gap Junctions (in Junctions context)

Channels between adjacent cells that allow the transport of ions, nutrients, and other substances.