Quizbowl science/Biology/cAMP
Cyclic AMP is a G-protein coupled receptor.
How it works[edit | edit source]
The G protein-coupled receptor is attached to the G protein. When the hormone activates the GPCR, the G-alpha subunit detaches, and the GDP inside of it turns into GTP. Then, the G-alpha subunit attaches to an effector enzyme, which then triggers the release of many secondary messengers.
This case[edit | edit source]
The effector enzyme is known as adenylate cyclase. Adenylate cycloase converts ATP -> cAMP + PP[1]. cAMP activates cAMP-dependent protein kinases.
Kinases add phosphate groups from ATP to something. So, cAMP-dependent protein kinases phosphorylate target proteins (typically cellular enzymes).
Breakdown[edit | edit source]
cAMP is broken down to AMP by cyclic nucleotide phosphodiesterase. However, this enzyme is inhibited by caffeine, thus causing stimulating effects.
See also[edit | edit source]
Youtube video: https://www.youtube.com/watch?v=VhLIfEmIHcM&list=PLmGAunhTA6--y7K04aQx1ZKhEuc-gsQIl&index=77
- ↑ pyrophosphate