Cell Communication

Critical for the survival and development of organisms, involving methods such as direct contact, local signaling, and long-distance signaling.

Cell-to-cell communication

Direct contact

A type of communication between cells through cell junctions; examples include gap junctions in animal cells and plasmodesmata in plant cells.

Local signaling

Communication method where a secreting cell releases ligands that travel short distances to target cells, as in paracrine or synaptic signaling.

Paracrine signaling

A form of local signaling where secretory cells release local regulators to affect nearby target cells.

Synaptic signaling

A type of local signaling occurring in the nervous system, where neurons secrete neurotransmitters across synaptic clefts to target cells.

Long-distance signaling

Communication that involves hormones traveling through vascular tissues or circulatory systems to reach target tissues.

Reception

The first stage of cell signaling where a ligand binds to its receptor on the target cell.

Transduction

The second stage of cell signaling, converting an extracellular signal into an intracellular signal through a sequence of changes.

Response

The final stage of cell signaling where the signal results in a specific cellular process or alteration.

Signal transduction pathway

A series of molecular changes that relay signals from receptors to cellular responses.

Second messengers

Small non-protein molecules that amplify the response and assist in relaying messages within cells.

GPCRs (G protein-coupled receptors)

The largest category of cell surface receptors that bind to G proteins, important for sensory systems in animals.

Ligand-gated ion channels

Membrane receptors that open or close in response to ligand binding, allowing ions to diffuse across the membrane.

Cyclic AMP

A common second messenger involved in amplifying cellular responses in signal transduction.

Protein kinase

An enzyme that relays signals by modifying other proteins in the signaling pathway.

Protein phosphatases

Enzymes that deactivate or shut off signaling pathways by removing phosphate groups from proteins.

Intracellular receptors

Receptors located in the cytoplasm or nucleus that bind to hydrophobic ligands that can pass through the plasma membrane.

Mutations

Changes in the genetic material that can affect the transduction of signals in eukaryotic organisms.