Can you explain the following based on its mode of enzyme kinetics:  1) Synthesis/degradation of enzymes 2) Allosteric regulation  3) Covalent modification

Which of the following aspects of catalysis by enzymes can NOT be explained by the Fischer Lock and Key Hypothesis? Enzymes will lower the activation energy barrier for reaction. Enzymes will specifically recognize their substrates. Appropriate substrates will bind to the enzyme to form a Michaelis complex. Enzymes have an "active site" where appropriate substrates will be bound. Two of the above cannot be explained by the Fischer "Lock and Key" Hypothesis.

The induced-fit theory aims to explain how the interactions between an enzyme and a sub- strate facilitate the catalysis of chemical reactions. Which of the following properties of enzyme-substrate interaction best explains enzymatic catalysis according to the induced-fit model? A B с D Environmental conditions can alter the affinity between a substrate and an enzyme by changing the conformation of the enzyme. Conformation changes in both the enzyme and the substrate due to their chemical in- teractions lower the activation energy of the catalyzed reactions. The interactions between an enzyme and a substrate depend on both structural and chemical compatibility and are therefore highly specific. Enzymes remain chemically unaltered between cycles of enzymatic catalysis while sub- strates are transformed into products.

Which of the following is TRUE under the following conditions: the enzyme concentration is 2.5 nM, substrate concentration is 75 nM, the KM = 150 nM, and the Vmax = 20 nmol/min a) The rate of the reaction is 20 nmol/min! b) The rate of the reaction is between 10 nmol/min and 20 nmol/min. c) The rate of the reaction is 10 nmol/min. d) The rate of the reaction is below 10 nmol/min. e) The rate cannot be determined from the above information.

How temperature, pH and salt affects the enzyme activity in terms of protein structure (primary, secondary, tertiary, quaternary) and other factors? Please explain briefly.

How many of the following statements are true? Allosteric enzymes display sigmoidal kinetics for plots of V versus [S] Allosteric enzymes exist in T and R states Allosteric enzymes display kinetics that becomes less sigmoidal in the presence of activators

Hb serves as our model for regulation of enzyme reaction rates. But Hb is not an enzyme. Explain the reasoning of Jacque Monod and his colleagues for invoking Hb as a "model enzyme."

Given the active site diagram below, indicate the mechanism(s) of catalysis. 5 HO OH HN OH ΝΗ *HN ΝΗ Zn²+ Acid-base, Metal ion 3 Metal ion, By Approximation Metal ion Acid-Base, By Approximation Acid-base

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Describe experimental enzyme inhibition and how it leads to a deeper understanding of enzyme mechanisms. Explain mechanism-based enzyme inhibition. Describe enzyme inhibition by a transition-state analog. For fluoroacetate and hypoglcyin A, explain how each of these mechanism-based inhibitors is converted to the actual enzyme inhibitor and how this inhibitor then inhibits the relevant enzyme..