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

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Cell Signalling and Transduction
The signaling molecules called steroid hormones

bind to cell surface receptors to trigger chemical cascades
never enter the blood of humans
are made in one location of the body but have their effects some distance away
are hydrophilic and so cannot penetrate the plasma membrane

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Cell Signalling and Transduction
Which of the following is true about a hydrophilic signaling molecule?

It might trigger a signal cascade that causes some effect in a cell
It is a steroid
Since it can enter the cell, it directly affects some specific cell process
Its receptor is located in the cytosol of the target cell

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