Biochemistry

THERMODYNAMICS AND FREE ENERGY MCQs

Total Questions : 6

Question 1. During the unfolding reaction of a helix, breakage of each hydrogen bond requires about 2kJ/mol. This implies hydrogen bonds are
  1.    slightly stronger in proteins than in water
  2.    slightly weaker in proteins than in water
  3.    much stronger in proteins than in water
  4.    not reformed with water
 Discuss Question
Answer is Option A. -> slightly stronger in proteins than in water
Question 2. If the Standard Gibb's free energy, ΔG°, for a reaction is positive then
  1.    the reactants will be favored
  2.    all of the reactant will be converted to product
  3.    the concentration of the reactants and products will be equal
  4.    the products will be favored
 Discuss Question
Answer is Option A. -> the reactants will be favored
Question 3. If the enthalpy change for a reaction is zero, ΔG° is equal to
  1.    TΔS°
  2.    lnKeq
  3.    -TΔS°
  4.    -ΔH°
 Discuss Question
Answer is Option C. -> -TΔS°
Question 4. Reactions that have positive standard free energy changes (ΔGo> 0) can be made to occur in cells by
  1.    manipulating the concentrations of products and reactants such that G/
  2.    coupling them to the hydrolysis of ATP
  3.    All of these
  4.    coupling them with exergonic reactions via a common intermediate
 Discuss Question
Answer is Option C. -> All of these
Question 5. The Standard Gibb's free energy, ΔG°, is
  1.    the residual energy present in the products at equilibrium
  2.    the energy required to convert one mole of reactants to one mole of products
  3.    the residual energy present in the reactants at equilibrium
  4.    the difference in the residual energy of reactants and products at equilibrium
 Discuss Question
Answer is Option B. -> the energy required to convert one mole of reactants to one mole of products
Question 6. The unfolding of regular secondary structure causes
  1.    no change in the entropy of the protein
  2.    large increase in the entropy of the protein
  3.    large decrease in the entropy of the protein
  4.    little increase in the entropy of protein
 Discuss Question
Answer is Option B. -> large increase in the entropy of the protein