Introduction to cell signalling MZ

Question 1

what is adrenaline, where is it produced

Answer 1

Produced by the adrenal glands (mostly),
adrenaline acts via adrenergic receptors
to produce a wide range of physiological
responses including the ‘fight or flight’
response

Question 2

How cells can respond to signalling? give 3 ways

Answer 2

• changing the structure of an existing protein eg. ion channel (very fast indeed)
• changing the post translational modification eg phosphorylation (fast)
• changing protein levels via gene expression (slow)

Question 3

stages at which a signalling
pathway can (and are) regulated in vivo

Answer 3

-Extracellular / ligand/ receptor
-Intracellular tansduction of the
signal
-Effectors can‘feedback’ onto their own pathways
Add a post-translational modification (or binding partner) to an existing protein that can act as a ‘switch’ that activates / inactivates protein function

Question 4

Two major groups of protein kinase in eucaryotes:

Answer 4

Two major groups of protein kinase in eucaryotes:

• serine / threonine kinase (S/T) - kinase enzyme that phosphorylates the OH group of serine or threonine
• tyrosine kinases (Y) - phosphate group is attached to the amino acid tyrosine on the protein.

functions as an “on” or “off”