Reference no: EM1381664

Question1. Phenylalanine residues are often found in what general locations in water-soluble globular proteins?

A. in beta turns (reverse turns)

B. on the surface of the protein

C. buried inside the protein

D. located more or less randomly in the interior and on the surface.

E. both A and B

Question2. The protein collagen has a high proportion (20% or more) of

A. asparagine and glutamine

B. proline and hydroxyproline

C. glycine

D. both A and B

E. both A and C

F. both B and C

Question3. Which of the following statements is correct?

A. Hemoglobin binds O2 cooperatively, while myoglobin does not.

B. Myoglobin binds O2 cooperatively, while hemoglobin does not.

C. Myoglobin binds O2 more weakly than hemoglobin.

D. The O2 binding curve (fractional saturation vs. pO2) for myoglobin is sigmoidal, while that of hemoglobin is hyperbolic.

E. both B and D

Question4. Which of the following statements is correct?

A. Hemoglobin binds O2 more tightly at pH 7.2 than at pH 7.4.

B. Fetal hemoglobin under physiological conditions binds O2 more tightly than maternal hemoglobin.

C. The T state of hemoglobin binds oxygen more tightly than the R state.

D. The heterotropic effector 2,3-bisphosphoglycerate increases the binding affinity of hemoglobin for O2.

E. None of the above statements is correct.

Question5. The Km for an enzyme

A. is equal to kcat, measured at low substrate concentration.

B. is the substrate concentration that gives a velocity that is half the maximum velocity.

C. is equal to the number of mols of substrate converted to product per mol of enzyme active site per unit time.

D. is equal to the maximum velocity of the enzyme, achieved at high substrate concentration.

E. None of the above.

Question6. An enzyme increases the rate of a reaction by _________ compared with that of the uncatalyzedreaction.

A. decreasing the overall entropy change for the reaction

B. decreasing the overall free energy change for the reaction

C. increasing the equilibrium constant for the reaction

D. decreasing the activation energy of the reaction

E. none of the above