Question: The following amino acid would stabilize the tertiary level of protein folding through which interaction?
Answer Choices:
disulfide bond peptide bond hydrogen bond ionic bond
Answer:
disulfide bond
Question: Choosing recrystallization solvents and determining oiling out
Answer Choices:
First solvent (to heat up and dissolve) → hot butyl acetate Second solvent (to add slowly while cooling) → n-butanol Stop adding when → first signs of cloudiness Which compound may oil out → A
Answer:
hot butyl acetate n-butanol first signs of cloudiness A
Question: You dissolve a solid Q in 197.0 mL solvent. 23.0% remains dissolved at 0°C. What is the original amount of solid dissolved?
Answer Choices:
(Not multiple choice — calculation-based)
Answer:
14.8 g
Question: What was the name of the amino acid that the author was investigating in the DiNardo paper?
Answer Choices:
Leucine Proline Cystine Alanine Aspartate
Answer:
Aspartate
Question: Determine the pH of the following aqueous solution that contains a [OH⁻] of 2.5 x 10⁻⁴.
Answer Choices:
9.7 10.4 10.8 8.8 7.4
Answer:
10.4
Question: Local folding of a protein occurs at what defined level of protein folding?
Answer Choices:
Primary Secondary Tertiary Quaternary All of the above
Answer:
Secondary
Question: The enzyme fumarase catalyzes… This is an example of:
Answer Choices:
biological activity chiral activity racemization stereoisomerization stereospecificity
Answer:
stereospecificity
Question: The washing step of recrystallization removes which category of impurities?
Answer Choices:
a. On the surface of the solid b. Within the crystal lattice
Answer:
a. On the surface of the solid
Question: Salt bridges in proteins are an example of __________.
Answer Choices:
Hydrogen bonds Ionic interactions Hydrophobic interactions van der Waals forces London dispersion forces
Answer:
Ionic interactions
Question: How many mL of boiling water are required to dissolve 142g of W? How many grams of W would crystallize out? What is the percent recovery?
Answer Choices:
(Not multiple choice — calculation-based)
Answer:
92.3% recovery
Question: Which of the following is an example of posttranslational modification of proteins?
Answer Choices:
Phosphorylation Acetylation Proteolytic Cleavage Glycosylation All of the above are examples of posttranslational modification
Answer:
All of the above are examples of posttranslational modification
Question: Enzymes are biological catalysts that enhance the rate of a reaction by:
Answer Choices:
decreasing the activation energy decreasing the amount of free energy released increasing the activation energy increasing the amount of free energy released increasing the energy of the transition state
Answer:
decreasing the activation energy
Question: The crystallization step of recrystallization removes which category of impurities?
Answer Choices:
a. On the surface of the solid b. Within the crystal lattice
Answer:
b. Within the crystal lattice
Question: The three-dimensional structure of a protein is determined primarily by:
Answer Choices:
electrostatic guidance from nucleic acid structure how many amino acids are in the protein hydrophobic interaction with Hsp’s that provide a folding framework modification during interaction with ribosome the sequence of amino acids in the protein
Answer:
the sequence of amino acids in the protein
Question: What is a common role of a coenzyme in a reaction as stated in class?
Answer Choices:
To lower the activation energy of a reaction further The donation of atoms to a reaction To alter the enzyme shape To assist the substrate by binding to the enzyme, enabling substrate to active site engagement
Answer:
To assist the substrate by binding to the enzyme, enabling substrate to active site engagement
Question: What reason did the author suggest for exemestane having a higher pKa than androstenedione when binding compared to androstenedione?
Answer Choices:
The Km was different between them There are additional hydrophobic contacts made The Ki and Km were different between them Their Keq were different None of the above
Answer:
There are additional hydrophobic contacts made