Signal Transduction

[stonecold]

Where does it start?

Is it when a signalling molecule binds to its receptor?
Or is it when second messenger molecules are activated?

[TrueLight]

its the whole process right?
where an extracellular signal results in an intracellular response

so when a signalling molecule binds to its receptor

actually... you could get a lipid soluble molecule binding to a receptor in the cytoplasm or somewhere inside the cell causing an intracelular signalling cascade leading to some type of response...

but in any case its still when a signalling molecule binds to its receptor

[stonecold]

Question 10 - VCAA06 - Answer is D
 
Consider two cells (X and Y) in a refl ex arc in the nervous system. Cell X is transmitting a signal to cell Y.
Signal transduction commences
A. in the cytosol of cell X.
B. along the axon of cell X.
C. in the myelin sheath of cell X.
D. at the synapse between cells X and Y.

Question 24 - VCAA08 - Answer is A
http://www.vcaa.vic.edu.au/vce/studies/biology/pastexams/2008/2008biol1-web.pdf

Haven't they said in the first question, it commences outside the cell, and in the other, they have said it commences inside the cell.

I am confused. *sighs*

[TrueLight]

from the point of signalling molecule binding to the point where there are changes in gene expression is signal transduction so stage 1 would make sense...

and Q10 makes sense too because signal transduction would occur when a neutransmitter binds a receptor ... so it doesn't commence in the cytosol, not along the axon, not in the myelin sheath so D would be the only answer that makes sense somewhat, but it wouldn't just occur in the synapse because thats just the gap but its the closest one that makes sense

[Toothpaste]

LOL stupid VCAA.

What I do think for the 2008 exam is that the "[" should really extend to include the receptor/the bound molecule.