The effectiveness of allosteric effectors in regulating metabolic pathways is based on their ability to—     interact with multiple substrate-binding sites on the target enzyme(s).     interfere with competitive inhibitors.     alter the concentration of the target enzyme(s).     denature the target enzyme(s).     change the conformation of the target enzyme(s).

For each of the statements below about the dUTPase enzyme, mark whether it is true or false. If it is false, change the language to make the statement true. _______If the dUTPase enzyme is the rate determining step in a larger metabolic pathway, the reaction likely lies near to equilibrium and is irreversible. _______For the dUTPase reaction, it is not likely that DG’ = DG°’ _______ dUTPase has a higher affinity for its substrate than for its product, but both of these are higher than the affinity for the transition state _______Kinetic analysis of dUTPase using Michaelis-Menten methods assumes that the formation of the E*S complex has a large negative value for DG

A newly developed drug is suspected to act by inhibiting its enzymatic target. To test this, the rates of reaction in the presence and absence of the new drug were determined. The results of these experiments have been plotted as a double reciprocal plot shown in figure 1 below.    Using this figure, calculate the values of Vmax and Km for the enzyme in the presence and absence of the drug. 2. Based on the figure and your answer, what type of inhibition is the new drug displaying?   3. Briefly explain how this type of inhibition exerts its action on an enzyme. Figure 1: Double reciprocal plot of reaction rate against substrate concentration in the presence and absence of a new drug.

You design an enzyme assay and choose a substrate concentration equal to the Km of the enzymatic reaction. You measure the rate of the reaction at this substrate concentration to be 75.0 μmol/min. Calculate the Vmax of this reaction in μmol/min. Express your answer with one decimal place.  Your previous attempt suffered from low signal-to-noise ratio when you used a substrate concentration equal to the Km. So you decide to increase the substrate concentration to 0.45 mM. You remeasure the rate of the reaction at this new substrate concentration and find it to be 135.0 μmol/min. Using the same Vmax value found above, calculate the Km value of this enzymatic reaction. Express your answer in μM with one decimal place.  Considering the previous two questions, what would be the rate of the reaction at a substrate concentration of 0.01 mM? Express your answer in μmol/min with one decimal place.

Which of the following about suicide substrates is incorrect? They form a covalent bond with the active site once activated. O Inhibition of suicide inhibitors cannot be overcomed by increased concentration of the substrate. O They are activated by the enzyme-catalyzed reaction mechanism. O They react irreversibly with the enzyme.

Which of the following are characteristics of catabolic metabolic pathways? (Choose all correct answers). Overall oxidation of initial substrates so redox reactions involve use of NAD+ as oxidizing agent, converted to NADH. Large initial substrates are broken down to smaller final products. Overall reduction of intial substrates so redox reactions involve use of NADPH as reducing agent, converted to NADP+. The pathways are overall exergonic (negative delta G). Net production of ATP as a result of the pathway. Essentially irreversible

Which of the following mechanisms of reversible enzyme inhibition describe the mode of action of nevirapine? Non-competitive Competitive Über-competitive Mixed Uncompetitive