Cell Signalling and Transduction
cAMP and cGMP are derived from

ATP and GTP by the actions of guanylate cyclase and adenylate cyclase respectively
ATP and GTP by the actions of adenylate cyclase and guanylate cyclase respectively
None of these
GTP and ATP by the actions of adenylate cyclase and guanylate cyclase respectively

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Cell Signalling and Transduction
In terms of cell communication, what do bacterial pathogens such as cholera and anthrax have in common?

They prevent the production of key signaling molecules
They alter the chemical structure of key signaling molecules
They block the normal functioning of signal transduction mechanisms
They destroy the receptors for key signaling molecules

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Cell Signalling and Transduction
A cell is known to respond to a particular signaling molecule. Which of the following must be true of this cell?

It is in the heart muscle
It contains the receptor for the signaling molecule
It is incapable of signal transduction
It is also the site of production for the signaling molecule

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Cell Signalling and Transduction
The binding of ligands to many G-proteins linked receptors leads to shortlived

increase in the concentration of certain intracellular signaling molecules called second messenger
decrease in the concentration of certain intracellular signaling molecules called second messenger
decrease in the concentration of certain extracellular signaling molecules called first messenger
increase in the concentration of certain extracellular signaling molecules called first messenger

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