Exam Questions and CORRECT Answers
CDK1 protein - CORRECT ANSWER - plays a central role in cell division control and
found in all eukaryotic cells ; member of large family of enzymes called protein kinases which
catalyze transfer of a phosphate from ATP to a target protein
Properties of water - CORRECT ANSWER - high surface tension, cohesive, and high
temperature to be converted to gas
cells are composed of - CORRECT ANSWER - carbon, nitrogen, oxygen , and hydrogen
and these elements are linked together via covalent bonds
4 major families of small organic molecules - CORRECT ANSWER - Sugars, fatty acids,
nucleotides, amino acids
polymers are formed/broken via - CORRECT ANSWER - condensation reactions that
require energy and broken via hydrolysis
electrostatic interaction (ionic bonds or salt bridges) - CORRECT ANSWER - occur
between oppositely charged molecules (fully charged groups) and strength of interaction is
determined by distance ; weak in water b/c charged molecules are shielded by polar water
molecules & weakened by ions that neutralize charges
Hydrogen Bonds - CORRECT ANSWER - form when hydrogen is covalently linked to
electronegative atom ; stronger outside water
Van der Waals Interaction - CORRECT ANSWER - occur between outer e- of
neighboring atoms when charge distribution is not equal; highly distanced dependent; when too
close they exhibit a repulsive force
, Hydrophobic effect - CORRECT ANSWER - displace water molecules and disrupt H-
bonding; cause water molecules that surround the molecules to become more ordered which is
energetically unfavorable, so they are forced to interact w/ themselves to minimize disruption of
water structure; form lipid bilayers, protein folding, and interactions between proteins
acids - CORRECT ANSWER - molecules that release protons in water
strong acid - CORRECT ANSWER - readily release a proton
weak acid - CORRECT ANSWER - only partially dissociate their proton
PKA - CORRECT ANSWER - strength of acids; the pH at which an acid is half
dissociated
Buffers - CORRECT ANSWER - resist change in pH; weak acids or bases that can bind or
release H+ within a specific pH range; resist dramatic changes in pH and can maintain a solution
within a tight pH range despite [H+]; WORK BEST TO MAINTAIN PH AROUND THEIR
PKA
Hydrophobic amino acids - CORRECT ANSWER - usually packed inside the core of a
folded protein structure away from water, which is due to the hydrophobic effect; hydrophobic
effect plays a major role in the forces that drive proteins to fold into precise three dimensional
structures; difference sizes of shapes allow many different ways of folding the core of proteins
Proline - CORRECT ANSWER - the side chain is bonded to the alpha carbon and the
nitrogen; ring structure constrains the number of conformations that it is capable of so it is not
capable of forming an alpha helix
Serine, threonine and tyrosine - CORRECT ANSWER - have a terminal hydroxyl group ;
they are polar and often found exposed in water in the final structure of proteins; hydroxyl group
is reactive