29 terms

Cellular Communication

cellular signals- reception, transduction and response
describe direct contact
cytoplasms of cells are connected: direct release of chemicals
short distance
measured in micrometers
neurons-- "jumping" of signal
long distance
measured in meters
across body-- stubbed toe
gap junctions
only in animal cells
direct contact
only in plant cells
direct contact
type of macromolecule used for cellular communication
proteins-3D, shape allows them to mold to a larger variety of ligands/signal molecule
signal molecule specific name
example of signal molecule
the initial transduction of a signal
the conformational change (altering of the shape) of the receptor after the ligand or signal molecule binds with it
receptors are found....
inside of the cell- cytoplasm and nucleus
plasma membrane
requirements for plasma membrane receptor binding
large and polar- hydrophillic
requirements for intracellular receptor binding
small and non-polar- hydrophobic
nerve growth factor
3 types of membrane-bound receptors
g-protein-linked, tyrosine kinases, ion-channel
steps of g-proteins
ligand attached, GDP->GTP, g-protein binds with adenylyl cyclase, ATP->cAMP, cAMP binds with protein kinase, gets ATP (phosphate), binds with phosporolase and enables the breakdown of glycogen to glucose
steps of tyrosine kinase
ligand attached, two parts come together to form a dimer, phosphates are added, inactive relay proteins bind with the tyrosine kinase and become activated so they can create a cellular response
steps of ion-channel
ligand attached, conformational change opens gate/channel, ions like sodium and calcium flow through into the cytoplasm, create cellular response, and the ligand/signal molecule is released, closing the gate/channel.
unable to function->ADP, GDP, etc.
ready to perform further processes-> ATP, GTP, etc.
why is the process of signal transducion a phosphate cascade/domino effect
chain reaction- each step creates a product needed to initiate the next reacion
what are the 2 most commonly used messengers
cAMP and CA2+ (calcium)
who discovered 2nd messengers
earl sutherland
what was earl sutherland studying and what 2nd messenger did he discover
studying glycogen breakdown in the liver- discovered cAMP
cAMP stands for
cyclic Adenosine MonoPhosphate
what role do protein kinases play in a transduction cascade
bind with the cAMP produced by the adenylyl cyclase and add an ATP
what role do phosphates play in a transduction cascade
they et added to cAMP by protein kinases so they can activate phosphorolase
what does GTPase do
discontinues the reaction by converting GTP to GDP, continuously changing the G-protein to its inactive state
three organs that use epinephrine
liver,muscle and cardiac (heart)
the response often occurs in the
nucleus or cytoplasm