Question

10.During protein degradation, a polypeptide chain is broken down into individual amino acids. Which of the following is false about this process?

a.It is an exergonic reaction.

b.The products have lower disorder than the reactants.

C.The products have lower free energy than the reactants

D.It is a catabolic process.

E.It is catalyzed by enzymes.

12.You quantitatively determine that an enzyme-catalyzed reaction has a ΔG of -8 kcal/mol. If you half the amount of enzyme in the reaction, what will be the ΔG of this reaction?

A.16 kcal/mol

B. -4 kcal/mol

C. 0 kcal/mol

D. 8 kcal/mol

E. -8 kcal/mol

18. Hemoglobin is a protein responsible for transporting oxygen in the blood of vertebrates. Carbon dioxide binds to hemoglobin at a distinct site from where oxygen binds. However, CO2 binding causes a conformational change in hemoglobin that decreases the protein’s binding affinity for O2. What kind of interaction does this describe?

A. catalyzed interaction

B. covalent binding

C. competitive interaction

D. irreversible interaction

E. allosteric interaction

19. Which of the following states the relevance of the first law of thermodynamics to biology?

A. Photosynthetic organisms produce energy in sugars from sunlight.

B. The total energy taken in by an organism must be greater than the total energy stored or released by the organism.

C. Living organisms must increase the entropy of their surroundings.

D. Energy is destroyed as glucose is broken down during cellular respiration.

E. Energy can be freely transformed among different forms as long as the total energy is conserved.

22. An artificial liposome (ie, a test-tube created vesicle), whose membrane contains no proteins and whose interior is filled with water is dropped into a beaker of 0.03 M sucrose solution (Note: Sucrose is a disaccharide). Which best describes what will quickly happen?

A. Sucrose will diffuse into the liposome.

B. The liposome will shrink as water leaves this vesicle.

C. Since there are no membrane proteins, nothing will cross the membrane.

D. Water will diffuse into the liposome, causing it to burst.

E. Sucrose will diffuse out of the liposome.

Answer 1

10)  a polypeptide chain is broken down into individual amino acids, this reaction is catalyzed by enzymes, a polymer is broken down to monomers, so this is a catabolic process, and this process releases energy, the entropy of the polymer is less than that of the monomers, that is these products have a higher disorder.

so the answer is b) The products have lower disorder than the reactants.

11) enzyme increases the rate of the reaction by lowering the activation energy it does not change the free energy of the reaction so the answer is E) -8 kcal/mol

12) oxygen and carbon dioxide binds to the hemoglobin via non-covalent interactions and the binding of both Carbon dioxide and oxygen to hemoglobin are reversible, carbon dioxide binds to a site other than the binding site of oxygen, allosteric interaction binding of a allosteric effector on the allosteric site influences the binding of other molecules, here binding of carbon dioxide decreases affinity of hemoglobin towards oxygen so the answer is E) allosteric interaction.