BIO 183 Cell Communication

Ligand

the signaling molecule

Receptor protein

binds the ligand

Direct contact

molecules on the surface of one cell are recognized by receptors on the adjacent cell

Paracrine signaling

signal released from a cell has an effect on neighboring cells

Endocrine signaling

hormones released from a cell affect other cells throughout the body

Phosphorylation

a common way to change the activity of a protein

Protein kinase

an enzyme that adds a phosphate to a protein

phosphatase

an enzyme that removes a phosphate from a protein

Steroid hormones

have a nonpolar, lipid-soluble structure, can affect regulation of gene expression

Channel linked receptors

ion channel that opens in response to a ligand

enzymatic receptors

receptor is an enzyme that is activated by the ligand

G protein-coupled receptor

a G-protein (bound to GTP) assists in transmitting the signal

G-protein

protein bound to GTP

G-protein-coupled receptor (GPCRs)

receptors bound to G proteins

Second messenger

generates the cellular response to the original signal

Depolarization

cell membrane less polarized, less negative relative to surrounding solution

Hyperpolarization

cell membrane more polarized, more negative