1. iodoacetamide inactivates enzymes by covalently modifying the r-group of ㅡㅡㅡ? 2.which of the following is true in the presence of competitive inhibitors? vmax decreaseskm decreasesvmax increaseskm increasesboth km and vmax decrease3.if an enzyme is operating at very high substrate levels, and an irreversible site specific inhibitor is added, so that the reaction rate is reduced by 50%, what is true about the resulting condition of the enzyme and/or substrate? half of the substrate does not bind to the enzymethe km of the enzyme has changed by 50%all of the enzyme molecules exhibit a 50% loss of activityhalf of the enzyme molecules are completely active and half of the enzyme molecules are completely inactivethe binding affinity of the substrate is different for all of the enzyme molecules4.which of the following is not true about irreversible enzyme inhibitors? they usually covalently modify the enzymethey often carry reactive groups that combine chemically with protein r-groupsthe protein r-groups modified are often nucleophiles such as sulfhydryl or hydroxyl groups. in many cases they alter the active site of the target enzymein most cases the inhibitor can be removed by dialysis5.which of the following is true for catalysis of a reaction by an enzyme? the equilibrium constant decreasesthe activation energy increasesthe initial velocity decreasesthe standard free energy of the reaction increasesthe initial velocity increases in the presence of an enzyme6.which of the following is true? the vmax is reached when the concentration of substrate is double the kmthe km value decreases in the presence of a competitive inhibitorat high substrate levels the reaction velocity increases in a liner manner with increasing s concentrationat very low substrate levels doubling the s concentration nearly doubles the observed reaction rate so that the rate increases in a linear manner. when the substrate level is equal to the km, the reaction rate does not increase if more substrate is added