A hydrated potassium ion is surrounded by a shell of water molecules oriented primarily with
their oxygen atoms toward the potassium ion.
True
In the detergent, sodium dodecyl sulfate, the sulfate groups are very hydrophobic
False
The combined effect of many weak noncovalent interactions can be very significant in
determining factors such as three-dimensional structure for large biological molecules
True
Water molecules that surround a less polar molecule in solution are immobile and ordered.
True
The strength of van der Waals forces between two molecules changes as the distance between
them changes.
True
The attractive force between two atoms is maximized when they are separated by the sum of
their van der Waals radii.
True
Salt bridges are often found on the surfaces of proteins where they are stabilized by water.
False
Hydrogen bonds in the interior of a protein or other macromolecule are stronger than those on
the exterior.
False
Micelles are stabilized in water by interactions of nonpolar molecules with each other.
True
Hydrophobic interactions are sometimes called ȈbondsȈ, because each one is as strong as a
covalent bond.
False
Proteins dissolved in water can be hydrolyzed by nucleophilic attack from the water molecules.
True
An intermediate formed by the enzyme glutamine synthetase, gamma-glutamyl phosphate, is
rapidly hydrolyzed by water if the enzyme is not around to protect it.
True
When acid is added to pure water, Kw, the ion-product constant of water, changes.
False
The equilibrium constant of water (Keq) is the rate that dissociation of the molecule occurs at
room temperature.
False
The H+ (or H3O+) in cells is the same concentration as that of undissociated water.
False
Hyperventilation can result in alkalosis because there is excessive loss of carbon dioxide and,
therefore a loss of carbonic acid.
True
Since the pKa of acetic acid is 4.8, it can be used to prepare a buffer to maintain physiological
pH.
False
The buffering capacity of a weak acid and its conjugate base is strongest when the pH = pKa
True
Synthetic compounds used as buffers are not as valuable for experiments as naturally
occurring compounds used as buffers.
False
Sign