Scientists could confirm that an allosteric effector increases the catalytic efficiency of an enzyme if it has what effect on kcat and Km?A.kcat decreases, Km increasesB.kcat decreases, Km remains unchangedC.kcat increases, Km decreasesD.kcat remains unchanged, Km increases

What effect does an enzyme have on a reaction?Question 4Select one:a.slows it downb.doubles the productc.stops itd.speeds it up

All of the following are true of enzyme-catalyzed reactions EXCEPT:A.the presence or absence of a post-translational modification may alter the activation energy Ea of the reaction.B.the enzyme does not affect the net reaction rate if the ratio of products to reactants equals Keq for the reaction.C.substrates can covalently modify the enzyme to cause a permanent decrease in the enzyme's turnover number kcat.D.the saturation of enzyme active sites by substrate molecules limits the maximum reaction velocity Vmax.Submit

Enzyme A catalyzes the conversion of substrate S to product P.  When enzyme A is phosphorylated, its kcat value changes from 10 s−1 to 5 s−1 and its KM value changes from 100 μM to 20 μM.  If equal concentrations of each enzyme form are used then compared to the unphosphorylated enzyme A, the phosphorylated form:A.has a higher catalytic efficiency and yields a faster reaction rate when [S] < 20 μM.B.has a higher turnover number and yields a faster reaction rate under saturating conditions.C.has a lower affinity for S and yields a slower reaction rate at all [S].D.is allosterically inhibited and yields a lower reaction rate at all [S].

Enzymes are able to speed up a reaction by lowering the activation energy:Question 59 Answer Choices   A.  only if the reaction is exergonic.   B.  only if the reaction is endergonic.   C.  if the reaction is endergonic or exergonic   D.  if ΔG is positive.

A catalyst is added to a reaction. Which of the following statements best describes the effect that a catalyst has on a reaction? Group of answer choicesThe catalyst gives the reactants more kinetic energyThe reaction rate is decreasedThe activation energy of the reaction is increasedThe activation energy of the reaction is decreased