Proteins/enzymes that can be regulated allosterically I. show a hyperbolic Michaelis-Menten curve II. can be regulated by molecules that differ structurally from a substrate II. can be both activated and inhibited IV. undergo only competitive inhibition 1, IIl and IV O ,1I, II and IV O land II O Il and III O , Il and III

Indicate how the observed Km of an enzyme would change in the presence of inhibitors having the given effect on a and a'. Increased a=a²=1.0 Decreased a> a 10 Answer Bank Unchanged a' > 1.0

Where does inhibitor binds on enzyme in mixed inhibition? A   Allosteric site B   Binds on substrate C    At active site D   Does not bind on enzyme

The substrate has been represented bound to the enzyme pocket. 20 Zn Part A: Part B: Substrate Part C: lle Val A Increasing V Arg 1451 (1)=0 Carboxypeptidase A A. Competitive inhibitor B. Irreversible inhibitor C. Allosteric inhibition D. Uncompetitive inhibition E. Non-competitive inhibitor F. -1/KM Benzylsuccinic acid Propose the types of biochemical interactions by which benzylsuccinic acid interacts with the carboxypeptidase A active site. 1. Hydrogen bond II. Ionic bond III.Hydrophobic interactions (Choose from options G-L) Which of the shown Lineweaver-Burk plots would you expect observe when benzylsuccinic acid I used to inhibit Carboxypeptidase A enzymatic activity? (Choose from options N-R) Increasing [1] Benzylsuccinic acid (shown below) has been identified as an inhibitor of carboxypeptidase A. Based on your understanding of enzyme- inhibitor interactions, identify a likely mechanism of inhibition by benzylsuccinic acid. (Choose from options A-E) in-o CH3 1/S) O V.(min) 20…

apple pectin is :     a a toxin made by the food-borne pathogen E. coli O157:H7          b a probiotic food supplement         c needed to make Latkes   and Jelly Doughnuts  during the 8 days of Hanukkah         d a prebiotic substance that promotes growth of “beneficial” probiotic bacteria in your intestines         e depolymerized (hydrolyzed) by the enzyme pectinase

on the activity of an enzyme can usually be overcome by increasing the concentration of substrate(s). Choose the best answer a competitive inhibitor the phosphorylation of the R groups of serine (S), threonine (T) and tyrosine (Y) a noncompetitive inhibitor an allosteric effector The effect of O 2 3 $ 4 G Search or type URL 67 dº % 5 MacBook Pro 6 7 * CO 8 -o .. E

1. If a molecule is interating with its side chains of an enzymes active site but it is not the substrate of the enzyme what kind of enzyme regulation is this?  2. What is the change in thetype of bond between Ser 80 -> Arg.  3. Will this change cause the complex to be more or less stable. Explain

Which statement is NOT completely true? O Cyanide, a poison, is an example of a reversible inhibitior. O noncompetitive inhibitors do not compete with substrates but have their own special site to bind called an allosteric site O noncompetitive inhibitors are molecules which decrease allosteric enzyme activity O Increased Creatine kinase in the blood may indicate a heart attack (caused by ruptured heart cells leaking the enzyme into the bood) O Reactants that are catalyzed are called substrates.

The enzyme Y catalyzes the elementary reaction AB→A + B An enzyme concentration of 1.0 µM Y can convert a maximum of 0.5 µM AB to the products A and B per second. Note: Since the concentrations of species in the cytoplasm of cells is small, the concentration unit of micromolar (uM or 10-6 M) is used for consistency with biochemical systems.

7. An enzyme-catalyzed reaction proceeds by the mechanism below: E+S1ES --2E+P E+A 3 EA EA+S4→ EAS --5→ EA + P E+I6 → EI EAS +17→ EAIS -8 EIS + P A. B. C. E = enzyme, S = substrate, I = inhibitor, P = product and A = activator Rate constants (k's) for the forward reactions are: K1, K2, k3, K4, k5, k6, k7, and k8 Rate constants (k's) for the reverse reactions are: k-1, k-3, K.4, k.6, and k.7 Write the enzyme balance for this mechanism. How many total equations will result from applying the RAPID EQUILIBRIUM ASSUMPTION? Using any concentrations of species in the mechanism and any of the rate constants (k's), write ONE of the equations that would result from applying the QUASI STEADY STATE ASSUMPTION. (ONLY ONE EQUATION; ANY OF THEM ARE FINE)