Cell Signalling and Transduction
Which of the following statements about G proteins is false?

They become activated when bound to GDP
They are involved in signal cascades
They must be active before the cell can make needed cAMP
They bind to and are regulated by guanine nucleotides

ANSWER DOWNLOAD EXAMIANS APP

Cell Signalling and Transduction
Nitroglycerin has long been administered to human patients suffering from chronic chest pain (angina). This medication works because it

interferes with chemical cascades that trigger contraction of heart muscle
is broken down into hormones that affect the heart
mimics the action of signal receptors
breaks down into nitric oxide, which increases blood flow to the heart

ANSWER DOWNLOAD EXAMIANS APP

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

ANSWER DOWNLOAD EXAMIANS APP

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

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; receptor; G proteins
signaling molecule; target cell; receptors
kinase; receptor; proteases

ANSWER DOWNLOAD EXAMIANS APP