Cell Communication Flashcards
Name the steps that are involved in cell communication
Receptor activation
Signal transduction
Response
Termination
Name the four players in cell
Communication
A signaling cell
A signaling molecule
A receptor molecule
A receptor cell
Describe endocrine signaling
Long distance signaling through the blood stream.
Ex: insulin
Describe paracrine signaling
Travels from near neighbor up to 20 cell diameters
Ex: growth factors and neurotransmitters
Describe auto time signaling
Cell sends and receives own signal.
Can tell it to decide if suicide is appropriate
How do cells respond to external signals
Use specific transmembrane proteins called receptors that bind to the signal(ligand) which causes a conformational change to the receptor, activating it. This transmits a signal inside the cells and generates a response
How can signals target some cells and not others?
Binding sites are specific for each signal. Some binding site receptors are not present on some molecules.
What are some responses a cell may have to a signaling molecule?
Migration
Activation of a protein
Change of shape
Describe a cell surface receptor
Surface receptors are transmembrane proteins that are specific for polar signaling molecules that can’t diffuse through the membrane. Bind outside of the cell and transmit a signal to the inside of the cell to generate a response
Describe a intercellular receptor
Receptor is located in the cytoplasm or the nucleus, specific for non polar signals that can diffuse across the membrane. When ligand binds, a change in shape of the receptor occurs leading to a respond
How can a signal be terminated in a cell?
The receptor could change shape to its inactive form or
The protein could change to its inactive form
( GTP➡️GDP)
Explain GCPR signaling.
When ligand binds, G protein in turned on GTP on. GDP off. G protein now activates enzyme. Makes secondary messenger to amplify message
Termination. GTP cleaves to GDP secondary messenger breaks down
Explain RTK signaling.
When not in use they are monomers. When growth factor is present 2 form a dimer, act as an enzyme and add phosphate to tyrosine which can bind to proteins and recruit them to the membrane to turn on a G protein.
Termination GDP to GTP
Explain ligand gated ion channels
Once ligand binds, conformational change occurs and opening a channel which allows for transport of ions. Leads to depolarization of cell and change in protein shape.
