Exam 2 (Post) Lectures 10-13 LO Flashcards
What is signaling? LO:10
Signaling is inter-cellular communication mediated by secreted molecules/ligands that bind receptors and trigger intracellular cascades in a regulated fashion to generate a specific cellular response
Signaling ….? LO:10
Serves to coordinate numerous processes needed for multicellular organisms
signals are amplified
differs from metabolic pathways
modes (5) of cell-cell communication differ in response time, receptor affinity, local ligand concentration
How does signaling start? LO:10
Signaling is initiated by receptors binding the secreted molecules/ligands, which are first messengers of varying molecular types
What do cell surface receptors bind to? LO:10
Hydrophilic or large ligands
What do intracellular receptors bind to? LO:10
Intracellular receptors bind to hydrophobic molecules or steroid hormones
Cell surface receptors fall into four classes….what are they? LO:10
2nd messengers, membrane potential, effector or receptor enzyme activation
What are secondary messengers? LO:10
Secondary messengers are small molecules that propagate the signal in some pathways
Signaling can use control mechanisms that switch proteins between down-regulated or inactive forms and activated forms. What are the major control mechanisms and the cycles and states on and off? LO:10
Protein phosphorylation controls enzyme activity and protein-protein interactions
G proteins and GTPase activity control protein-protein interactions
What else can impact signaling response? LO:10
Not just ligand-receptor binding but also downstream effectors such as amplification
What eventually happens to a signal? LO:10
The signals must be terminated and there are multiple ways to do so related to the surface receptor level
Structures of ligand-gated ion channels LO:11
Oligomeric with extracellular domain (ligand binding) and transmembrane helices (channel)
What type of signaling is associated with ligand-gated ion channels? LO:11
Endocrine signaling (distant hormones that travel far distances)
Ligands and there relation to neurology? LO:11
Ligands are neurotransmitters, gating leads to depolarization of neuronal membranes
What is the main function of RTK pathways? LO:11
RTKs autophosphorylate intracellular domains for docking in initial steps of signaling pathways
What is the functions of RTKs LO:11
Growth, metabolic, also important anticancer targets
