Cell Communication Basics

What is direct cell-to-cell communication?

Communication that occurs through a junction that allows cells to exchange molecules directly and alter each other’s behavior

How does signaling via ligands differ from direct cell-to-cell communication?

A cell secretes signaling molecules into the bloodstream or extracellular fluid to be picked up by a target cell rather than through physical contact

What is a ligand?

A signaling molecule that binds to a receptor to initiate a cellular response

What determines whether a ligand can bind to a receptor?

Complementary shape between the ligand and the receptor

What happens when a ligand binds to its receptor?

Binding leads to a cellular response

What are the two main types of ligands described?

Hormones (long-distance signaling) and local regulators (short-distance signaling)

What is a hormone?

A ligand that travels a long distance through the bloodstream from a gland to another part of the body

What are local regulators?

Ligands produced by cells in close proximity for short-distance communication