Chapter 11 - Section 3 Flashcards
Transduction
Cascades of molecular interaction relay signals from receptors to target molecules in the cell.
T or F - multi step pathways can amplify signals but a few molecules cannot produce a larger cellular response.
False
Which molecules relay a signal from receptor to response?
Proteins
How is transduction related to dominos.
the receptor activates another protein, which activates another, and so on, until the protein producing the response is activated
In terms of transduction, how are some signals in pathways transmitted?
By a cascade of protein phosphorylations
Protein Kinases
transfer phosphates from ATP to protein, a process called phosphorylation.
Protein phosphatases
remove the phosphates from proteins, a process called dephosphorylation
The phosphorylation and dephosphorylation system acts as _____
a molecular switch, turning activities on and off or up or down, as required
First messenger
The extra cellular signal molecule that binds to the receptor
Second messenger
Small, nonprotein, water-soluble molecules or ions that spread throughout a cell by diffusion.
What are common second messengers?
Cyclic AMP and calcium ions
Cyclic AMP (cAMP)
One of the most widely used messengers
Adenylyl Cyclades
An enzyme in the plasma membrane, converts AP to cAMP in response to an extra cellular signal.
cAMP usually activates _______
protein kinase A, which phosphorylates various other proteins
Why is calcium an important second messenger?
Because cells can regulate its concentration.
