Transduction

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.

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

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