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

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

ANSWER DOWNLOAD EXAMIANS APP

Cell Signalling and Transduction
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; target cell; G proteins
signaling molecule; target cell; receptors
kinase; receptor; proteases
signaling molecule; receptor; G proteins

ANSWER DOWNLOAD EXAMIANS APP

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

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

ANSWER DOWNLOAD EXAMIANS APP

Cell Signalling and Transduction
The signaling molecules called steroid hormones

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

ANSWER DOWNLOAD EXAMIANS APP