Chapter 11: Cell Communication Flashcards
Paracrine Signaling
A signaling cell releases messenger molecules into extracellular fluid
Signal Transduction Pathways
The series of steps involved in the conversion of a cell surface signal to a cellular response
Synaptic Signaling
A nerve cell releases neurotransmitter molecules into the narrow synapse separating it from its target cell
Hormones
Chemical signals that travel to more distant cells
Reception
A signal molecule binds to a receptor protein, causing it to change shape
Ligand
A small molecule that specifically binds to a receptor protein (larger molecule) and usually induces a change in the receptor’s conformation
Receptor tyrosine kinases
Receptor proteins with enzymatic activity that can trigger several pathways at once
G-protein-linked receptors
receptors that work with the aid of a G protein to trigger a specific transduction pathway
Ligand-gated ion channel
Opens or closes the protein pore (when chemical signal binds to channel); allows the blocking or flow of specific ions through the membrane
Transduction
Cascades of molecular interactions relay signals from receptors to target molecules in the cell
Protein kinases
enzymes that transfer phosphate groups from ATP to proteins
Protein phosphatases
enzymes that remove phosphate groups from proteins; shuts down signaling pathways when the extracellular signal is no longer present
Second messenger
small, water-soluble molecules or ions; rapidly relay the signal from the membrane-receptor-bound “first messenger” into a cell’s interior
Adenylyl Cyclase
a membrane protein (protein built into plasma membrane) that converts ATP to cAMP
IP3
A second messenger that binds to and opens ligand-gated calcium channels in the ER
