BIOL124 L 3

HideShow resource information
  • Created by: Katherine
  • Created on: 02-06-16 15:33
What is transduction:
Cascades of molecular interactions that relay signals from receptors to target molecules in cell
1 of 25
Molecuels that relay a signal from receptor to response are mostly...
2 of 25
What is phosphorylation?
When protein kinases transfer phosphates from ATP to protein
3 of 25
Where does phosphorylation occur?
On serine, threonine residues
4 of 25
What does phosphorlyation lead to?
Protein activation
5 of 25
What do protein phosphatases do?
Remove phosphates from proteins - in dephosphorlyation.
6 of 25
What does the phosphorylation and dephosphorlyation system act act
acts as a molecular swith - truning activities on and off . The activity of a particular pathway is therfore regulated by the ration of kinase to phosphate activity within a cell.
7 of 25
What are second messengers?
Small non protein water soluble moelcules or ions that readily spread thoughout a cell by diffusion.
8 of 25
What are common second messengers
Cyclic AMP and calcium ions
9 of 25
What is cyclic AMP?
a widely used second messenger
10 of 25
What is Adenylyl cyclase?
An enzyme in the plasma membrane that converts ATP to cAMP in response to extraceullular signal.
11 of 25
Camp can be broken down by... to form...which is...
Phosphodiesterase, AMP, inactive
12 of 25
What bacterium causes cholera?
Bacterium vibrio cholerae
13 of 25
Where does the bacteria colonise?
The small intestine.
14 of 25
How does Cholera affect G proteins?
It affects the G protein involved in regulating salt and water excretion.
15 of 25
What is the process of cholera and G proteins?
It activates a G protein - the G protein is unable to hydrolyse GTP to GDP - so is switched on all the time. This leads to constant activation of adenylate cyclase and continuous camp production.
16 of 25
What do the high Camp levels result in?
They activate the CFTR causing a dramatic efflux of cl- ions and water from infected cells, leading to watery diarroea.
17 of 25
What are calcium ions?
Second messengers - important becuase second messengers can regulate its concentraiton.
18 of 25
Under normal conditions, intraceullular calcium concentration is...
Very low
19 of 25
Pathways leading to the release of calcium invovle...
iNOSITOL TRIPHOSHATE AND DIACYGLCEROL (DAG) As additional second messengers
20 of 25
What is Calmodulin?
A specific calcium modulated protein. It contains 4 ca2+ binding sites.
21 of 25
What does calcium binding to calmodiun do?
Induces conformational changes, allowing CaM to bind to other proteins causing inactivation or activation.
22 of 25
What are the 4 aspects of fine tuning to consider?
Amplifying the signal (and the response), specificity of the response, overall efficiency of the response, enhanced by scafforlidng proteins, termination of the response.
23 of 25
What are scaffolding proteins?
Large relay proteins to which other relay proteins are attached.
24 of 25
What do scaffolding protein do?
Increase signal transduction eficiency by grouping together different proteins invovled in the same pathway.
25 of 25

Other cards in this set

Card 2


Molecuels that relay a signal from receptor to response are mostly...



Card 3


What is phosphorylation?


Preview of the front of card 3

Card 4


Where does phosphorylation occur?


Preview of the front of card 4

Card 5


What does phosphorlyation lead to?


Preview of the front of card 5
View more cards


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Signal transduction resources »