A signal cascade induced by adrenaline or thyroxine must begin with receipt of the signal molecule by a surface receptor involves the activation of a G protein results in the activation of a sequence of enzymes needed for the cell effect All of these TRUE ANSWER : ? YOUR ANSWER : ?
The signaling molecules called steroid hormones bind to cell surface receptors to trigger chemical cascades are hydrophilic and so cannot penetrate the plasma membrane never enter the blood of humans are made in one location of the body but have their effects some distance away TRUE ANSWER : ? YOUR ANSWER : ?
A cell is known to respond to a particular signaling molecule. Which of the following must be true of this cell? It is incapable of signal transduction It contains the receptor for the signaling molecule It is in the heart muscle It is also the site of production for the signaling molecule TRUE ANSWER : ? YOUR ANSWER : ?
In the signal transduction mechanism known as protein phosphorylation All of these receptor kinases play a key role in triggering the signal cascade the signaling molecule binds to a surface receptor phosphorylated proteins act with enzymes to trigger the signal cascade TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following processes involve the combining of a message from one signaling molecule with that of another to either enhance or inhibit a cellular effect? Signal amplification Signal integration Signal reception Signal transduction TRUE ANSWER : ? YOUR ANSWER : ?
In terms of cell communication, what do bacterial pathogens such as cholera and anthrax have in common? They block the normal functioning of signal transduction mechanisms They alter the chemical structure of key signaling molecules They prevent the production of key signaling molecules They destroy the receptors for key signaling molecules TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following statements about G proteins is false? They are involved in signal cascades They bind to and are regulated by guanine nucleotides They must be active before the cell can make needed cAMP They become activated when bound to GDP TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following is not a type of signaling molecule? Adenylate cyclase Insulin Testosterone Thyroxin TRUE ANSWER : ? YOUR ANSWER : ?
Cell signaling can be classified into None of these three distinct types based on the distance over which the signaling molecules act two distinct types based on the distance over which the signaling molecules act three distinct types based on the signaling molecules TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following is a hormone whose action requires a cell surface receptor? Adrenaline Progesterone Growth factors Nitric oxide TRUE ANSWER : ? YOUR ANSWER : ?