For a lot of enzymes that work on fatty acids, the rate determining step is the release of the product from the active site. This means that the activation energy for product release is much higher than the free energy of catalysis. What enthalpic or entropic contributions would make the activation energy for product release so high and explain?

The highest energy point of the serine protease reaction is the formation of the tetrahedral oxyanion intermediate on the original carbonyl carbon of the scissile peptide bond. True or False? DIPF is an irreversible inhibitor of serine proteases. True or False? The acyl-enzyme intermediate is the transition state of the reaction. True or False?  Serine proteases are classified as isomerases. True or False?

The products of a pathway, or the products of specific reactions in the pathway, will often inhibit upstream regulatory enzymes in that pathway. That makes sense - if the products of a pathway are abundant, then the pathway can be shut off to save energy or divert molecules into other pathways. We can use a similar rule of thumb to predict whether a pathway will be active in different biological states. For example, the liver stores glucose (in the form of glycogen), and will release glucose into the bloodstream when blood sugar levels drop. This glucose can come from the synthesis of glucose or breakdown of stored glycogen. This is important for maintaining blood sugar levels. What would you predict is the relationship between blood sugar levels and glycogen phosphorylase enzyme activity? A positive relationship (when blood sugar levels are high, glycogen phosphorylase activity is also high). A negative relationship (when blood sugar levels are high, glycogen phosphorylase activity…

If you can clearly visualize the chymotrypsin mechanism of action, you should be able to picture the structure of the transition state right after the enzyme attacks the first substrate. Think hard about what we have covered, and visualize that transition state accurately:

CH₂OH 애 H2COPO 2- ATP OH 1 애 애 어 애 The class of the enzyme catalyzing the reaction shown in this figure is a(n) Choose the one best answer. ligase 매 +ADP 매

Discuss an enzyme that acts as a catalyst in a biological system.  What reaction(s) does it catalyze?  What kinds of problems arise if the enzyme isn't working properly?  In what ways is the enzyme's activity regulated?  Other interesting facts about the enzyme? Don't forget to cite your source(s).

You are trying to confirm that an enzyme you are studying has the following amino acid in its active site, and that this amino is critical for catalysis: HN- H3NⓇ Which of the following inhibitors could you use to provide evidence of the importance of this amino acid for enzyme function? Tetranitromethane 2,3-Butanedione Diethylpyrocarbonate lodoacetate Nevirapine

Consider the following free energy diagram for an uncatalyzed and enzyme-catalyzed reaction. Select all the statements that are true. Without enzyme With enzyme A+B Time AB O a. The rate of the enzyme catalyzed reaction is faster than the uncatalyzed reaction O b. The change in free energy for the reaction is greater in the catalyzed reaction, compared to the uncatalyzed reaction O c. The enzyme stabilizes the transition state for the reaction Od. The reaction is exergonic е. The reaction is now spontaneous due to the addition of enzyme Released Energy

Catalysis involves overcoming the activation energy barrier of a reaction. What are three ways by which enzymes can do this?

Discuss the following statement: “enzymes and heat are alike in that both can speed up reactions that—although thermodynamically feasible—do not occur at an appreciable rate because they require a high activation energy. diseases that seem to benefit from the careful application of heat—in the form of hot chicken soup, for example—are therefore likely to be due to the insufficient function of an enzyme.”