45. Which of the environmental factors affect the interactions between amino acids that in turn determine the shape of a protein?
A. pH B. ion concentration C. hydrophilic or hydrophobic properties of the environment
D. temperature E. All of these choices are correct.
46. When a peptide bond is created between two amino acids:
A. the amino group of the first amino acid is joined to the carboxyl group of the second.
B. the carboxyl group of the first amino acid is joined to the amino group of the second.
C. the carboxyl group of the first amino acid is joined to the carboxyl group of the second.
D. the amino group of the first amino acid is joined to the amino group of the second.
47. Based on what you know of ATP's chemistry, which of the substances is most likely to have similar functions in energy-management processes?
A. potassium ions (K+) B. phospholipids C. lysine (amino acid)
D. Steroids E. guanosine nucleotide triphosphate
48.
(A) ATP + H2O → ADP + Pi ΔG1 = -7.3 kcal/mol
(B) Glucose + Pi → Glucose 6-phosphate + H2O ΔG2 = +3.3 kcal/mol
(C) Glucose + ATP → Glucose 6-phosphate + ADP ΔG = -4 kcal/mol
49. What are the type of above reactions in order of A, B, C
A. Endergonic, exergonic, coupling
B. Coupling, coupling, endergonic
C. Coupling, coupling, exergonic
D. Exergonic, endergonic, coupling
50. Why scientists believe that naturally occurring elements might have drove the first reactions that led to life?
A. Many enzymes contain and require metal ions as cofactors in addition to peptide molecule
B. Metal ions might, by themselves, catalyze chemical reactions, magnesium and zinc accelerate the RNA and DNA polymerization.
C. Presence of Iron-sulfur minerals form in mid-ocean hydrothermal vent where oxygen is absent.
D. H2S and FeS has been shown to catalyze a number of plausibly pre-biotic chemical reactions, including the formation of pyruvate
E. All of the above
51. An anabolic reaction decreases entropy within the system because the reaction results in a more ordered macromolecule. A) true B) false
52. Which of the statements about the formation of a peptide bond are true? Select all that apply.
A) The reaction is anabolic. B) The reaction is non-spontaneous.
C) The reaction has a positive ΔG. D) The reaction is endergonic. E) all of the above
53. Some ions that facilitate enzyme-catalyzed reactions are capable of catalyzing reactions independently of an enzyme. A) true B) false
54. The amino acids that actively contribute to catalysis in the active site of an enzyme do not have to be located close to each other in the primary sequence (the linear sequence of amino acids) of the protein.
A) true B) false