Topic 6 Flashcards
(13 cards)
How do cells pick up signals?
Cells pick up signals from the outside by either,
1) Binding to receptors on outside of the cell
2) Taking them up on the inside and passing the message on
Describe the steps of Receptor Tyrosine Kinase (RTK)
1) Signal is received by receptor
2) Dimerization of receptor
3)The RTK are now active and can cross-phosphorylate eachother
Describe the rest of the pathway
1) Signal is received by receptor and activates it
2)RTK somehow activates TK1
3)TK1 phosphorylates and activates TK2
4)TK2 phosphorylates TFa.
5)TFa enters the nuclues
What do kinases do? How to they do this?
Kinases phosphorylate others, either activating or deactivating them. They do this by
1)taking phosphates from ATP and then turning it into ADP
2) Adding the phosphate onto hydroxyl OH groups on amino acid groups.
What removes a phosphate?
Phosphatase removes phosphates.
What is a feedback loop?
A feedback loop is when something further on in the pathway signals to something earlier.
Whats a postive feedback loop?
A postive feedback loop tells something upstream to increase activity.
Whats a negative feedback loop?
A negative feedback loop tells something upstream to decrease activity.
Always a ________ component affecting an _________ component?
Always a DOWNSTREAM component affecting an UPSTREAM component.
Describe Ubiquitin mediated proteolysis.
1)Ubiquitin group gets added to a protein
2)Protiens with this ubiqutin tag will be targeted for destruction
3)Anything ubiquinated will be destroyed by the proteasome.
Describe Receptor mediated endocytosis
This is when the cell doesnt want anymore signals to be picked up by receptors.
1)Receptors get brought into the cell through endoctyosis creating a vesicle
3)Vesicle is sent to the lysosome to be degraded
Describe signal amplifaction
Signal amplifaction is, each step amplifying the signal by spreading it to mulitple downstream messengers
Explain Crosstalk
Crosstalk is used to communicate messages between different pathways.
