56.A 65-year-old man presents to the neurology clinic with a several year
history in which he has less and less energy and spontaneity, memory loss
(especially recent events), and mood swings. He is described by his wife as
uncharacteristically slow to learn and react and shying away from anything
new, preferring the familiar, confused, getting lost easily, and exercising
poor judgment. He scores poorly on the mini-mental status examination
(MMSE). This disease is believed to be caused by protein misfolding. Chap-
eronins regulate protein folding in which of the following ways?
a. Stimulating aggregation of proteins
b. Contributing folding information to the native protein
c. Controlling the docking of the signal peptide with its receptor on the rough
endoplasmic reticulum
d. Inhibiting proteolytic activity of misfolded proteins
e. Using their ATPase activity to bind and release themselves from hydrophobic
regions of the protein
57.A 23-year-old man who is allergic to peanuts has a plain vanilla ice
cream cone at a local ice cream store. Unfortunately, the server did not suf-
ficiently clean the scoop after serving a cup of peanut brittle ice cream. The
young man begins to have an allergic reaction and reaches for his inhalator
filled with albuterol, a beta-adrenergic drug that binds to beta receptors in
the cells of the respiratory airways. The diagram below shows the mecha-
nism involved in binding of albuterol to its receptor. Which of the follow-
ing statements regarding the molecule labeled “B” in the diagram is true?
128 Anatomy, Histology, and Cell Biology