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Worksheetslecture 12 (383)
Total questions: 14
Worksheet time: 7mins
What is the primary function of G protein-coupled receptors (GPCRs)?
To synthesize proteins
To regulate blood sugar levels
To signal through activating second messenger molecules
To transport oxygen in the blood
Which of the following is a widely used second messenger in GPCR signaling?
Cyclic AMP (cAMP)
Glucose
Adenosine triphosphate (ATP)
Nicotinamide adenine dinucleotide (NAD)
What enzyme is responsible for the formation of cAMP from ATP?
Protein kinase A
Adenylyl cyclase
Calmodulin
Phospholipase
What happens when a ligand binds to a GPCR?
It stimulates the Gsα subunit to release GDP
It inhibits adenylyl cyclase
It decreases cAMP levels
It activates protein synthesis
Which subunits detach from the G protein upon activation?
Gsα and Gsβ
Gsα only
Gsβ and Gsγ
Gsα and Gsγ
What is the role of protein kinase A (PKA) in GPCR signaling?
To degrade cAMP
To activate target proteins
To inhibit signal transduction
To transport calcium ions
What are the two components of cAMP-dependent protein kinase?
Ligand and receptor
Alpha and beta subunits
GTP and GDP
Regulatory and catalytic subunits
Which of the following is NOT a second messenger mentioned in the text?
Cyclic AMP (cAMP)
Inositol trisphosphate
Diacylglycerol
Nitric oxide
What is the outcome of GPCR signaling through cAMP?
Direct activation of DNA
Amplification of the signal
Inhibition of adenylyl cyclase
Decreased calcium ion levels
Which of the following statements is true regarding GPCRs?
They do not interact with second messengers
They are exclusively found in muscle cells
They can be regulated by kinases
They only function in the presence of calcium ions
What is the primary role of cyclic AMP in cellular signaling?
To synthesize proteins
To transport nutrients across cell membranes
To serve as a second messenger that amplifies signals
To act as a structural component of membranes
Which of the following is a function of GPCRs?
Transporting ions across membranes
Regulating gene expression
Signal transduction
Producing energy
What is the effect of GTP binding to the Gsα subunit?
It inhibits the production of cAMP
It leads to the activation of adenylyl cyclase
It promotes the degradation of cAMP
It causes the subunit to remain attached to GDP
What is the significance of the regulatory and catalytic subunits in cAMP-dependent protein kinase?
They determine the specificity of the enzyme
They are responsible for the degradation of cAMP
They inhibit the enzyme's activity
They transport cAMP into the nucleus
