BSCI330 cellular communication Flashcards
how do cells communicate withe each other
via receptors, which bind to signal molecule ligands
what is the difference between hydrophobic and hydrophilic ligands
hydrophobic ligands can cross membranes to activate intracellular receptors while hydrophilic ligands have to bind to cell-surface transmembrane receptors
what do second messengers do
transmit the signals from the cell surface to the effectors, which is required by signal transduction from cell-surface receptors
what are the 3 basic modes of signaling
ion channels, enzyme-coupled receptors, G-protein-coupled receptors
what are the 3 general cell communication steps
reception, transduction, response
what is paracrine signaling
affect only cells in the immediate environment of the signaling cell
what is endocrine signaling
travel long distances through the bloodstream to act on distant targets
what is synaptic signaling
travel via axons
what is autocrine signaling
a cell secretes signal molecules that can bind back to its own receptors
what is contact-dependent signaling
bound to surface of cell so have to have cell-to-cell contact and only influence cells that contact it
what happens when a cell doesn’t receive specific combination of signals
cell activates apoptosis
what do cell responses vary according to
unique collection of receptor proteins
the intracellular signaling machinery by which the cell integrates and interprets what it receives
what do morphogens do
diffuse out from signaling centers in developing tissues, creating a morphogen concentration gradient
what are the types of cell signals
mechanical: adhesion to substrates, membrane distortion, sound
light
heat
chemical
what can lipid soluble signals do
can diffuse across the plasma membrane
- steroid hormones and gaseous signaling molecules
travel to their target cells via carrier proteins
bind to intracellular receptors
what are hydrophilic/lipid insoluble signals
polar, water soluble molecules
neurotransmitters, peptide hormones, growth factors
cannot cross cell membranes and must bind to sites on cell surface receptors
what are the 3 major types of cell surface receptors
ligand-gated ion channels, enzyme coupled receptors, G-protein coupled receptors
what are ligand-gated ion channels
binding to ligands causes channel to open and allows specific ions to flow through
what are enzyme-coupled receptors
activate an enzyme when activated
what are G-protein coupled receptors
activation of receptor causes a change in GTP vs GDP binding of a switch protein, which turns downstream enzymes on or off
what is a kinase cascade
passing down phosphorylation of kinases
what are first messengers
cell-surface receptors that carry the signal across plasma membrane
what do second molecules do
combination of activated enzymes and small intracellular molecules called second molecules amplify the signal and spread it throughout the cell
what do effector proteins do
regulate cell’s response
