Cell structure and function: Cell Communication

Question 1

local signalling

Answer 1

signals act on nearby cells
paracrine: fibroblast growth factor
synaptic: neurotransmitters like acetyl choline
autocrine: act on signalling cell

Question 2

long distance signalling

Answer 2

hormones into bloodstream and bind to receptors in target cell

Question 3

main steps if cel signalling

Answer 3

Reception: ligand causes shape change in receptor
Transduction: relay molecules
response

Question 4

receptor locations

Answer 4

membrane: water soluble molecules
non-membrane: lipid soluble

Question 5

G protein couple receptor

Answer 5

transmembrane proteins and pass PM 7 times. multiple different ligands
couple with G protieins which are on or off
function: development, sensory

Question 6

Ligand gated ion channels/receptors

Answer 6

have a gate that opens when ligand binds. ions enter through.
ions then used in cellular response (eg. nervous). ligand disassociates and gate closes

Question 7

signal transduction pathways

Answer 7

ligand bidns to receptor -> triggers response in relay molecule(s) -> activates cell response (e.g activate protein)

Question 8

Protein kinases

Answer 8

enzymes. transfer phosphate group from ATP to another (and then others) specific protein, ending in protein activation. series of kinases adding phosphate to the net kinase (phosphorylation). Serine residue often receive phosphate.

Question 9

Phosphatases

Answer 9

enzyme removes phosphate groups to deactivate proteins after cellular response has finished

Question 10

Second messengers

Answer 10

another molecule used in cascade
cAMP: single phosphate that can activate a protein causing cellular response. made by adenyl cyclase
calcium ions: potent messenger, that is high concentration in some areas and not in others and this is highly regulated (muscle cells use these ions)