G-protein coupled receptor pathways and second messenger systems tested on USMLE Step 1.
34 cards · basic cards · AI-written, checked twice. Edit anything.
- How many transmembrane domains does a GPCR have?
Show answer
Seven- What are the three subunits of a heterotrimeric G protein?
Show answer
Alpha, beta, and gamma- In the resting (inactive) state, what nucleotide is bound to the G-alpha subunit?
Show answer
GDP- Ligand binding to a GPCR causes the alpha subunit to exchange ____ for GTP.
Show answer
GDP- What intrinsic enzymatic activity terminates G-alpha subunit signaling?
Show answer
GTPase activity, which hydrolyzes GTP back to GDP- Which G-alpha subunit stimulates adenylyl cyclase?
Show answer
Gs alpha- Which G-alpha subunit inhibits adenylyl cyclase?
Show answer
Gi alpha- Which G-alpha subunit activates phospholipase C?
Show answer
Gq alpha- Adenylyl cyclase converts ATP into the second messenger ____.
Show answer
cAMP- What enzyme does cAMP activate?
Show answer
Protein kinase A (PKA)- What happens to PKA's catalytic subunits when cAMP binds its regulatory subunits?
Show answer
They are released from the holoenzyme and become active- What enzyme degrades cAMP to AMP?
Show answer
Phosphodiesterase- What two second messengers does phospholipase C produce from PIP2?
Show answer
IP3 and DAG- What does IP3 trigger in the cell?
Show answer
Release of calcium from the endoplasmic reticulum- What enzyme does DAG activate?
Show answer
Protein kinase C (PKC)
FlashKeepers