cell signalling Flashcards
name the 3 steps in cell signalling
binding, transduction, response
what are the 5 types of intercellular communication
autocrine, paracrine, contact-dependent, neuronal and endocrine
describe autocrine communication
cell-same type of cell, nearby.
describe contact-dependent communication
No secretions. cell signal on membrane connects directly with receptor on neighbouring cell
describe 3 things about paracrine signalling
1) signals secreted
2) short distance
3) can be local mediators involved
describe the 2 long range cell-cell communication
1) neuronal - action potential along neurone, chemical transmitters are released into synapses and bind to receptors on the target cell
2) endocrine - signals (eg insulin) are secreted into the blood stream where they can travel long distances to target cells
what happens inside a cell when a signalling chemical binds to a receptor in the membrane?
what might cell signals provoke (3)
survival, division, differentiation, apoptosis
what does ACH provoke in cardiac muscle?
hyperpolarisation leading to bradycardia
what does ACH do in skeletal muscle
depolarisation -> contraction
what sort of ACH receptors does cardiac muscle have?
muscarinic ACH receptors
what sort of receptors are muscarinic ACH receptors
G protein coupled
what are nicotinic ACH receptors
non-selective cation ion channels
where can you find nicotinic ACH receptors?
skeletal muscle
name the factors that can alter an intercellular response to a signal binding to the protein
type of cell, type of receptor, type of secondary messenger/cascade
what are the 5 parts of the cell signalling pathway
1) signalling molecule
2) receptor
3) 2ary messengers
4) transcription factors
5) cellular effects
at what point in the cell signalling pathway can mutations have effect?
any
describe cAMP pathway
1) hormone (eg adrenaline)
2) GPCR
3) adenylyl cyclase->PKA-> phosphorylation of kinases
4) CREB
5) cell growth/cell cycle progression/ hormone release
where are Ca2+ ions usual stored?
ER or cytoplasm
what do protein kinases do
phosphorylate proteins using a phosphate group from ATP
what do protein kinases do
phosphorylate proteins using a phosphate group from ATP
which molecule dephosphorylates proteins
phosphatase enzyme
what is a phosphorylation cascade
intracellular pathway. phosphorylated proteins are themselves protein kinases so they keep the phosphorylation going until the desired cell action is achieved
what 2 pathways are activated by insulin binding to the cell membrane?
MAP kinase
PI3 kinase
