Cell Communication Flashcards
what must a cell do in order to receive a signal?
communicate and amplify them
what is the signal transduction pathway?
a cascade of reactions caused by a binding of the signal messenger
what does the singal transduction do?
produces the physiologval effect of the signal
what is local communication?
through direct contact or by secreting local acting GFs and cytokines
what are cytokines?
a large family of small secreted proteins released by cells which effect the interactions between cells
what is long distance communication?
uses hormones to communicate
where are hormones made?
endorcrine glands
what is a gland?
a group of cells in the body that synthesises substances such as hormones for release into the bloodstream
what is cortisol?
glucocorticoid that is produced in the cortex of the adrenal gland that alters carbohydrate metabolism
what is aldosterone?
mineralocorticoid produced in the cortex of the adrenal gland which regulates salt and water balance
what is thyroxine?
produced by the thyroid gland and stimulates metabolism and heat generation
what is the difference between the GFs and cytokines?
GFs are produced constituitively yet cytokines are carefully regulated
in what ways do hormones act?
long range and endocrine fashion
in what ways do cytokines act?
over a short distance and in autocrine or paracrine fashion
what is neural signalling?
nerve cells or neurones elicit responses by the release of a neurotransmitter at synapses
what is contact dependance?
singal molecules in the plasma membranes of the signal cellinteract with membrane receptors on the target cell
what alters the cells sensitivity to signalling molecules?
the receptor density in the membrane
how does the ligand messenger model work?
ligand is the first messenger and the ions produced as a result are the second messengers
what 3 receptors are often a cause of disease?
ligand gated ion channels, G-protein coupled receptors and tyrosine kinases
what are ligand gated ion channels?
transmembrane proteins open or close in response to ligand
why are ligand gated ion channels important?
for neurotransmitters to carry a nervous impulse
what do GPCR’s look like?
a polypeptide chain with 7 transmembrane alpha helices
what is the structure of GPCR’s?
outer temrinal binds to ligand and inner terminal binds to G protein
what is the heterotrimeric G protein?
made up of alpha, beta and gamma subunits that are activated by GPCR’s
