Signal Transduction 3 Flashcards
Define transduction
Cascades of molecular interactions relay signals from receptors to target molecules in cell
What are signal molecules made of?
Proteins
What is the easiest way to transmit a signal?
Protein phosphorylation
What happens in phosphorylation?
Protein kinases transfer phosphates from ATP to protein
Where does phosphorylation most commonly occur?
Serine and threonine
What does phosphorylation normally lead to?
Protein activation
What happens in dephosphorylation?
Protein phosphatases removes phosphates from proteins
Describe secondary messengers.
Small
Non protein
Water soluble molecules
Readily spread throughout a cell by diffusion
What are the 2 common secondary messenger?
Calcium ions and cyclic AMP
What is the role of adenylyl cyclase?
Converts ATP to cAMP in response to an extracellular signal
What does cAMP usually activate?
Protein kinase A
What is the second messenger in a GPCR pathway?
cAMP
What does cholera effect?
G proteins involved in regulating salt and water excretion
Is the intracellular calcium concentration usually high or low?
Very low
What additional secondary messengers are used in pathways that release calcium?
IP3
DAG
