Bioc 384 Exam 1 BIOCHEMICAL 384 1ST
EDITION OF COMPLETE QUESTIONS
AND CORRECT ANSWERS
Select the TWO true statements below describing the standard free energy change (delta G) and the
equilibrium constant (Keq).
The equilibrium constant is equal to ratio of the concentration of reactants over products at equilibrium.
If the value of the equilibrium constant is known, the value for the standard free energy change can be
determined.
The value for the standard free energy change is constant for a given reaction.
The standard free energy change is a function of enzyme concentration in the reaction.
A reaction is spontaneous when the standard free energy change and the equilibrium constant are both
negative values. - Correct Answer: If the value of the equilibrium constant is known, the value for the
standard free energy change can be determined.
The value for the standard free energy change is constant for a given reaction.
Which of the of four amino acids residues listed in the choices below are all most likely to be buried in
the interior of a water soluble protein?
Ala, Asp, Cys, Lys
Glu, Thr, Phe, Arg
,Glu, Trp, Tyr, His
Cys, Thr, Ser, Glu
Leu, Ile, Val, Ala - Correct Answer: Leu, Ile, Val, Ala
G-C rich regions of DNA are more stable to denaturation than A-T rich regions. Why? (choose one
correct answer).
The primary reason G-C rich regions are more stable is that G-C base pairs have three hydrogen bonds,
and A-T base pairs have only two hydrogen bonds.
Counterions (like Mg2+) bind preferentially to G-C rich regions, enhancing their stability.
More DNA binding proteins bind to G-C rich regions, and therefore stabilize these structures.
G-C rich regions of DNA have more favorable base stacking energy than A-T rich regions - Correct
Answer: G-C rich regions of DNA have more favorable base stacking energy than A-T rich regions
Urea and β-mercaptoethanol (BME) were critical to the success of Anfinsen's protein folding
experiments using the enzyme ribonuclease. What was the most important conclusion resulting from
this experiment that earned Anfinsen the Nobel Prize?
, That ribonuclease can form four disulfide bonds that function as "staples" holding the protein together.
That BME is strong reductant that can permit protein folding to occur following a precise pathway.
That the hydrophobic collapse model is the best explanation for protein folding in an aqueous solution.
That primary structure of a protein has all the information necessary to specify tertiary structure. -
Correct Answer: That primary structure of a protein has all the information necessary to specify tertiary
structure.
A hydrogen bond can best be described as a
weak noncovalent interaction.
strong covalent interaction.
weak covalent interaction.
weak hydrophobic effect.
strong ionic interaction. - Correct Answer: weak noncovalent interaction.
Which of the following process are driven by the hydrophobic effect? Four numbered processes are
correct, choose the letter below that contains all four of the correct numbered processes.
1. Dissolving sodium chloride in water to brine chicken.
2. Separation of oil and vinegar in salad dressing.
EDITION OF COMPLETE QUESTIONS
AND CORRECT ANSWERS
Select the TWO true statements below describing the standard free energy change (delta G) and the
equilibrium constant (Keq).
The equilibrium constant is equal to ratio of the concentration of reactants over products at equilibrium.
If the value of the equilibrium constant is known, the value for the standard free energy change can be
determined.
The value for the standard free energy change is constant for a given reaction.
The standard free energy change is a function of enzyme concentration in the reaction.
A reaction is spontaneous when the standard free energy change and the equilibrium constant are both
negative values. - Correct Answer: If the value of the equilibrium constant is known, the value for the
standard free energy change can be determined.
The value for the standard free energy change is constant for a given reaction.
Which of the of four amino acids residues listed in the choices below are all most likely to be buried in
the interior of a water soluble protein?
Ala, Asp, Cys, Lys
Glu, Thr, Phe, Arg
,Glu, Trp, Tyr, His
Cys, Thr, Ser, Glu
Leu, Ile, Val, Ala - Correct Answer: Leu, Ile, Val, Ala
G-C rich regions of DNA are more stable to denaturation than A-T rich regions. Why? (choose one
correct answer).
The primary reason G-C rich regions are more stable is that G-C base pairs have three hydrogen bonds,
and A-T base pairs have only two hydrogen bonds.
Counterions (like Mg2+) bind preferentially to G-C rich regions, enhancing their stability.
More DNA binding proteins bind to G-C rich regions, and therefore stabilize these structures.
G-C rich regions of DNA have more favorable base stacking energy than A-T rich regions - Correct
Answer: G-C rich regions of DNA have more favorable base stacking energy than A-T rich regions
Urea and β-mercaptoethanol (BME) were critical to the success of Anfinsen's protein folding
experiments using the enzyme ribonuclease. What was the most important conclusion resulting from
this experiment that earned Anfinsen the Nobel Prize?
, That ribonuclease can form four disulfide bonds that function as "staples" holding the protein together.
That BME is strong reductant that can permit protein folding to occur following a precise pathway.
That the hydrophobic collapse model is the best explanation for protein folding in an aqueous solution.
That primary structure of a protein has all the information necessary to specify tertiary structure. -
Correct Answer: That primary structure of a protein has all the information necessary to specify tertiary
structure.
A hydrogen bond can best be described as a
weak noncovalent interaction.
strong covalent interaction.
weak covalent interaction.
weak hydrophobic effect.
strong ionic interaction. - Correct Answer: weak noncovalent interaction.
Which of the following process are driven by the hydrophobic effect? Four numbered processes are
correct, choose the letter below that contains all four of the correct numbered processes.
1. Dissolving sodium chloride in water to brine chicken.
2. Separation of oil and vinegar in salad dressing.
