Cell Signaling and Communication

These flashcards cover key concepts from the lecture on cell signaling and communication mechanisms within and between cells.

What is intercellular signaling?

Communication between cells.

What is intracellular signaling?

Communication within a cell.

What are ligands?

Molecules that bind to specific receptors to deliver signals.

What are the four categories of chemical signaling?

Paracrine signaling, endocrine signaling, autocrine signaling, and direct signaling across gap junctions.

What is paracrine signaling?

Signals that act locally between nearby cells.

How do endocrine signals differ from paracrine signals?

Endocrine signals originate from distant cells and usually produce a slower but longer-lasting response.

What is autocrine signaling?

Signals produced by signaling cells that can also bind to the ligand they release.

What are gap junctions?

Connections that allow small signaling molecules to diffuse directly between adjacent cells.

What are internal receptors?

Receptors located in the cytoplasm that respond to hydrophobic ligands.

What role do cell-surface receptors play?

They bind external ligands and perform signal transduction.

How do viruses recognize their hosts?

By binding to specific cell-surface receptors on the host cell.

What are two types of cell-surface receptors?

Ion channel-linked receptors and G-protein-linked receptors.

What is the function of G-proteins in cell signaling?

They interact with ion channels or enzymes in the membrane to propagate a signal.

What effect do secondary messengers, like Ca2+, have in cells?

They propagate signals within the cell after activation by the receptor.

What is apoptosis?

Programmed cell death that a cell can initiate when damaged or superfluous.

What is quorum sensing in bacteria?

A mechanism where bacteria communicate with each other using signaling molecules called autoinducers.