CELL SIGNALING Flashcards
What is signal transduction?
The transmission of signal from the plasma membrane to the inside of the cell
True/False: signal molecule binding identical receptors can produce different responses in diff cells.
Why/why not?
True
Because their receptors connect to different internal pathways.
What are the five models of signaling?
Endocrine Paracrine Synaptic signaling Autocrine Cell-contact mode Nerve mode
Endocrine signaling?
Acts on a distant target via hormones throigh the blood stream
Transmits signals within self. A type of signaling utilized in development
Autocrine
Cancer cells use this method of signaling.
Autocrine
What is the shortest mode of signaling? How does it occur?
Contact dependent signaling.
Ligand binds the surface influences target cells’ with receptors
Paracrine signaling? Example?
Ligands affect cells in the immediate environment. Utilizes local mediators
What type of signaling invol signal conc gradient?
Paracine signaling
What signaling is the transport of electric signals along axons and release of signaling molecule at synapses?
Synaptic (Nerve Mode) Signaling.
What is an example of a contact dependent signaling?
Immune and antigen presenting cells.
What are the major classes of cell surface receptors?
Ion-channel-linked receptors
G-protein linked receptors
Enzyme-linked receptors
Could be transmitter ligand-gated or ionotropic and can function in synaptic signaling
Ion-Channel Liked receptors
Regulates enzymes or ion channels via trimeric GTP binding proteins
G-protein linked receptors
Single pass transmembrane protein, ligand binding site outside the cell and a catalytic site inside
functions as enzyme or are assoc. with enzymes that they activate
Enzyme-linked receptors
First Messengers
Molecules that signal btw cells,
Are secreted via exocytosis
released via diffusion throug plasma membrane
Binds signaling cell’s surface
Second messengers
Small diffusible molecules engaged in intracellular signaling
Examples of second messenger molecules
cAMP, cGMP, Diacylglycerol(DAG), Calcium ions
What is the difference btw 1st and 2nd messengers?
1st messengers bind signaling cell’s surface, are released out through plasma membrane
2nd messengers are small molecules and engaged in intracellular signaling. They are utilized in rapid, amplified general responses
Relay proteins
Pass the message to the next signaling component
Messanger Protein
Carry signal from one part of the cell to another
Adaptor Proteins
Link one signaling protein to another
Amplifier proteins (enzyme, Ions)
Incr the signal by producing many intracellular mediators or acrivating many downstream intracellular signal proteins.
Transducer proteins
Convert the signal into a different form;
