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Since enzymes are not rigid molecules but rather flexible proteins, which of the following may be attributed to this fact?   a.  active sites are able to conform to the shape of the substrate   b.  catalytic residues are oriented in such as way to aid in bond breakage and bond formation   c.  strain is placed upon the substrate while it binds to the enzyme   d.  near-attack conformations are achieved during formation of the transition state during an enzyme catalyzed reaction   e.  all of the above are correct

Which statement is correct about the Michaelis-Menten constant, Km, for the kinetic mechanism below?   a.  It is numerically equal to the substrate concentration required to achieve one half the maximum velocity.   b.  Its defined as Km = k1/(k−1 + k2).   c.  It is approximately equal to the dissociation constant for the enzyme-substrate complex to E + P.   d.  The value of Km is constant for an enzyme regardless of the specific substrate molecule used to determine it.   e.  Its numeric value has the units of moles−1.

15. The catalytic mechanism below is an example of:   a.  covalent nucleophilic catalysis.   b.  covalent electrophilic catalysis.   c.  specific base catalysis.   d.  general base catalysis.   e.  low barrier hydrogen bond catalysis.  

In transforming the Michaelis-Menten equation into a straight line equation, y = mx + b, the Lineweaver-Burk double reciprocal plot, which of the following is NOT a true representation?   a.  slope = Km/Vmax   b.  y-intercept is 1/Vmax   c.  x-intercept is 1/Km   d.  y = 1/V   e.  x = 1/[S]

All are characteristic of allosteric enzymes EXCEPT:   a.  Effectors may show stimulatory or inhibitory activity.   b.  They have multiple subunits.   c.  They obey Michaelis-Menten kinetics.   d.  The regulatory effect is by altering conformation and interaction of subunits.   e.  Binding one subunit impacts binding of substrate to other subunits.  

All of the following are correct statements about enzyme regulation EXCEPT:   a.  Enzymes can be inhibited by the products they produce.   b.  Enzymes can be inactivated by the addition of a functional group.   c.  Coenzyme and substrate availability can regulate enzyme reaction rate.   d.  The reaction rate slows as equilibrium is approached.   e.  The activity of an enzyme is covalently affected by allosteric regulators.

The free energy of activation, ΔG, is defined as:   a.  The average free energy of the product formed.   b.  The rate of a chemical reaction in relationship to the concentration of reactant molecules.   c.  The energy required to raise the average energy of one mole of reactant to the transition state energy.   d.  The amount of energy released by a spontaneous reaction.   e.  The lowest point on a free energy diagram.

What two enthalpic factors stabilize DNA in double-helical form at low temperature?

An enzyme with a total concentration of 2 X10-10 mol/L working at Vmax catalyzes the conversion of substrate into product with a rate of 25 X10-6 mol of product per minute.  What is the enzyme’s turnover number?  

Please download and print out the math questions, then scan and email your answers to me via Canvas or to cdickins@fiu.edu If you do not have a printer, just send me your answers on a blank sheet. Make sure your name is on the page.  Once you are finished answering the questions please press the “Finish” button.  If using your phone to upload your answers, please use the “Adobe Scan” or “Genius Scan” app to scan a copy of your answers. The exam will close after 120 minutes.  You must send me your math answers within that time frame. Good luck! Download the math problems for Final Exam (PDF)