WorksheetsQuiz on G Protein–Coupled Receptors and Signal Transduction ch 11 (383)
Total questions: 14
Worksheet time: 7mins
What is the primary function of G protein-coupled receptors (GPCRs)?
To transport oxygen in the blood
To act as membrane receptor proteins
To degrade cellular waste
To synthesize proteins in the cytoplasm
What type of proteins are G proteins classified as?
Transport proteins
Structural proteins
Guanine-nucleotide binding proteins
Enzymatic proteins
How many transmembrane α helices do GPCRs have?
Six
Eight
Five
Seven
What is the role of adenylyl cyclase in GPCR signaling?
To bind ligands
To transport ions across membranes
To convert ATP to cAMP
To deactivate G proteins
What happens to G proteins when GTP is bound?
They bind to DNA
They degrade rapidly
They act as molecular switches
They become inactive
Which domain of GPCRs interacts with G proteins?
Cytosolic domain
Catalytic domain
Transmembrane domain
Ligand binding domain
What is the effect of GDP binding to G proteins?
Increases cAMP levels
Activates the G protein
Deactivates the G protein
Stimulates ligand binding
What is the function of phosphodiesterase in GPCR signaling?
To bind ligands
To activate G proteins
To degrade cAMP
To synthesize cAMP
What is the role of kinases in relation to GPCRs?
To bind ligands
To amplify the signal
To deactivate the receptors
To transport G proteins
Where is the N-terminus of GPCRs located?
In the transmembrane domain
In the extracellular fluid
In the catalytic domain
In the cytosol
What are the three subunits of heterotrimeric G proteins?
Kappa, lambda, mu
Delta, epsilon, zeta
Theta, iota, sigma
Alpha, beta, gamma
What is the primary second messenger used by GPCRs?
Calcium ions
cAMP
IP3
DAG
What happens to the G alpha subunit when it is bound to GTP?
It becomes inactive
It is released from the receptor
It binds to GDP
It activates downstream signaling
What is the function of the ligand binding domain in GPCRs?
To bind signaling molecules
To interact with G proteins
To degrade cAMP
To transport ions
