Cell Communication (Chapter 11) Flashcards
(19 cards)
Signal transduction pathway
series of steps by which signal on cell’s surface converted into specific cellular response.
allows bacteria to sense local population density.
Local regulators
messenger molecules that travel only short distances
Hormones
long-distance signaling.
Three stages of cell signaling
Reception, Transduction, response
Ligand
Binding between signal molecule and receptor.
Most signal receptors
Plasma membrane proteins
Tree main types of membrane receptors
G protein-coupled receptors (GPCF), Receptor tyrosine kinases (RTK), Ion Channel Receptors.
GPCR
Plasma membrane receptor that works with help of G protein.
G protein
Works as on/off switch
Intracellular Receptors
Found in cytosol or nucleus, hydrophobic chemical messengers like steroid and thyroid, turns on specific genes
Signal Transduction
involves multiple steps
Multistep pathways
amplify signal, provide opportunities for coordination and regulation of cell response.
Protein Kinases/ Phosphorylation
transfer phosphates from ATP to protein.
Protein phosphatases/ dephosphorylation
remove phosphates from proteins.
Second messengers
small, non-protein, water-soluble molecules or ions that spread through by diffusion. Initiated by GPCRs and RTKs
Output response
Cell’s response to extra-cellular signal.
Apoptosis
programmed or controlled cell suicide, prevents enzymes from leaking out of dying cells and damaging neighboring cells.
Caspases
main proteases (enzymes that cut up proteins that carry out apoptosis
Apoptosis triggered by (3)
Extracellular death-signaling ligand,
DNA damage in nucleus
Protein misfolding in endoplasmic reticulum
