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WorksheetsCell and Molecular Biology: Signal Transduction
Total questions: 15
Worksheet time: 8mins
Which of the following plasma membrane receptors activate signaling pathways usually by forming molecular dimers that result in protein phosphorylation reactions upon binding of their specific ligand?
G protein-coupled receptors
Receptor tyrosine kinases
Ligand receptors
When a __________ reaches its __________ , there is a specific means of receiving it and acting on the message. This task is the responsibility of specialized proteins called __________ .
signaling molecule; receptor; G proteins
signaling molecule; target cell; G proteins
signaling molecule; target cell; receptors
G-proteins are classified as ________________,
heterotrimeric
tetrameric
trimeric
. In GPCR signaling, the G protein Inactive alpha subunit gives up associated cAMP and takes up GDP, conformation changes again, released from beta/gamma subunits and interacts with target proteins.
True
False
G proteins are inactivated by ________ activity of alpha subunit.
GTPase
Receptor Tyrosine Kinases
______________cell-surface receptors with intracellular domains that have intrinsic enzymatic activity.
Receptor Tyrosine Kinases (RTKs)
Cell surface receptors
Intracellular receptors
G-coupled proteins receptors
Growth factors or mitogens stimulate RTKs to promote cell division and it is facilitated by the _________________.
mitogen activating protein (MAP) kinase signaling cascade
phospholipase C (PLC)/calcium pathway
The MAP Kinase signaling cascade begins the ___________.
Ras GTPase
RTK Activation
G-protein coupled receptors (GPCRs) have _______ transmembrane domains and are associated with an intracellular G-protein
five
seven
nine
The target enzyme for Gq proteins is ____________.
PI3-kinase
adenylyl cyclase
phospholipase C-beta
The cAMP/PKA signal transduction pathway is used in cells is an example of ______.
“fight or flight” response
Changes in motility
Changes in gene expression
Which step would be the first step in a signal transduction pathway?
phophorylation of proteins
activation of protein
binding a ligand to a receptor
What is the role of protein kinase in a signal transduction pathway?
activates a molecule by adding a phosphate to the target molecule
activates a molecule by removing a phosphate from the target molecule
deactivate a molecule by removing a phosphate from the target molecule
deactivate a molecule by adding a phosphate to the target molecule
What is the purpose of transduction?
send a signal to a target cell
respond to a signal pass along internally
pass along a signal through the cell to the location where the cell response will occur.
Phosphorylation is the process by which a ____ is added to a protein to activate it.
acetyl
sulfate
phosphate
