Chapter 11 part 2 Flashcards
(27 cards)
Cells in a multicellular organism communicate with _____________, and this can be __________
signalling molecules, long or short distance
What are cell junctions? How do they work?
Can connect cytoplasms of cells, which lets molecules that act as signals dissolved in cytosol pass between cells
What is cell surface molecule communication? Where is it found?
(molecule on cell surface binds to receptor on another molecule)
This type of local signaling is especially important in embryonic development, the immune response, and in maintaining adult stem cell populations.
paracrine signaling
Signalling cells release molecules which regulate target cells
Synaptic signalling
Nerve cells release molecules called neyrotransmitters across a synapse to a target cell
Endocrine signalling
Endocrine cells secrete hormones (usually through the bloodstream) and bind to a specific receptor on a specific type of cell
What are hormones?
A type of secreted chemical that travels long distances through bodily fluids and acts on target cells to change their function
What are the three steps of cell communication?
- Signal reception (signalling molecule binds to receptor protein)
- Signal transduction (Once molecule binds to receptor, receptor changes somehow and converts bond to cellular response. Usually takes several steps).
- Cellular response
How does the GPCR signaling pathway work?
- GCPR is activated
- G protein binds to GCPR
- GTP displaces GDP (Activates g protein)
- Activated G protein dissociates from receptor and binds to enzyme which alters its shape/function
- Enzyme can start up next step, which causes cellular response
- G protein hydrolyzes GTP, turns it back into GDP and phosphate (Inactivates GTP)
6 G protein leaves enzyme, inactivates it. G protein can be reused, GTPase functino shuts down activity quickly when signaling molecule leaves.
How does the receptor tyrosine kinase signaling pathway work?
What do receptor tyrosine kinases do?
Regulate cell growth and division by receiving growth factors
What does GCPR do?
Helps many neurotransmitters and hormones act
Most water-soluble signaling molecules bind to specific sites on ______________ receptor proteins that transmit information from the _____________ to the ________________.
transmembrane, extracellular environment, inside of the cell
A g protein coupled receptor is what kind of receptor?
Cell-surface transmembrane receptor
What do GCPRs work with?
G protein
What do G proteins do?
Bind GTP
What are GCPRs used for?
Yeast mating factors, neurotransmitters, hormones, embryonic development, sensory reception
What do G proteins function as? How do you know what state it’s in?
Molecular on/off switches, whether GDP/GTP is attached
GDP makes it inactive, receptor and GTP make it active (usually working with an enzyme)
How does a GTP molecule bind to its receptor?
Once the receptor activates, it changes shape and lets GTP molecule bind to it.
What do RTKs do?
Phosphorylate tyrosines on other RTK in a dimer
What is the tyrosine kinase’s structure and function?(ADD FUNCTION)
The part of the receptor protein that extends into the cytoplasm
Intracellular receptor proteins are found in either the ______or _______ of _____________
cytoplasm or nucleus, target cells
The signal-activated receptor activates __________, which activates _____________, and so on, until _________ is activated.
another molecule, yet another molecule,the protein that produces the final cellular response
How is protein activity regulated?
Phosphorylation and dephosphorylation of proteins
