2. The two diagrams to the right il-lustrate plots of steady-state ki-netic studies to characterize the in-FB0.8-nH =3.50.6-teraction of heart muscle phos-phofructokinase-1 with a non-phy-siological, synthetic substrate fruc-tose-6-sulfate. Because the kcat issmaller than that for the natural0.4-0.2-10 μΜ20 μΜ48 μΜsubstrate, higher enzyme concen-trations could be used. The resultsshow the influence of increasing2-3.2-0.4-concentrations of ATP on the initial-0.6->velocity of the enzyme catalyzedreaction in the presence of noAMP (•), 10 µM AMP (•), 20 µMAMP (-), and 48 µM AMP (-).-0.8-412202836445260687684921.21.62.02.4[AΤP (μΜ)log[ATP] (µM)(a)how ATP interacts with the enzyme in the case of no AMP (•).Write the reaction in words catalyzed by the enzyme for the alternative substrate, describe(b)with respect to the binding of AMP and ATP to the allosteric effector sites on the enzyme.Explain the physical significance of the displacement of the Hill plots to the right in panel B10 (µmoles/min/mg)A (A - "A) bo|

Phosphofructokinase-1 (PFK-1) is a rate limiting enzyme of the glycolytic pathway. PFK-1 catalyzes…

Answered: 2. The two diagrams to the right il-…

Biochemistry

6th Edition

ISBN:9781305577206

Author:Reginald H. Garrett, Charles M. Grisham

Publisher:Reginald H. Garrett, Charles M. Grisham

Chapter18: Glycolysis

Section: Chapter Questions

Problem 17P

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2. It is known hemoglobinopathies, whi ch arise due to mutations in one of histidines a- or B- chains binding with the iron in the heme gro up.These mutations stabilize the iron in Fes form. Some drugs (eg. sulfonamides) or chemicals( eg.anilin) also can cause methemoglobinemia. Suggest, how change the properties of Hb in these cas es. For this:1)Describe the structure and function of Hb A as a transport protein. 2) Explain the role ofiron ions in act ive centers of Hb for the binding of O23) How many molecules of Oz can bind mutant Hb, if mutation occurs in a- subunits? 4) Why can ascorbic acid be used to tr eat of such patients.
An experiment was carried out to measure the reaction rate of hydrolysis of acetylcholme (substrate) with serum enzymes (Eadie, 1949). In the experiment, two experiments were conducted, namely experiment 1 without using a prostigmine inhibitor and experiment 2 using a prostigmine inhibitor at 1.5 x 10^-7 mol/l. the data obtained are: a. Is prostigmine competitive or noncompetitive inhibitor? b. determine the value of km and rmax for the two experiments, compare
The enzyme serine hydroxymethy ltransferase (SHMT) catalyses the conversion of serine into glycine. The fo llowing table gives the initial rates, vo, for the SHMT-catalysed reaction of the substrate serine at var ious concentratio ns of serine, lSI.[S]/(mmol dm-3) 10 20 30 40vo(μmol dm-3 s-1) 1.63 2.94 4.10 4.95Use the data to determine the values of the MichaelisMenten constant, the maximum velocity of the reaction, and the maximum turnover number of the enzyme.
At 37 °C, the serine protease subtilisin has kcat = 50 s-1 and KM = 1.4 × 10-4 M. It is proposed that the N155 side chain contributes ahydrogen bond to the oxyanion hole of subtilisin. J. A. Wells and colleagues reported (1986, Phil. Trans. R. Soc. Lond. A 317:415–423) the following kinetic parameters for the N155T mutant of subtilisin: kcat = 0.02 s-1 and KM = 2 × 10-4 M.(a) Subtilisin is used in some laundry detergents to help remove protein-type stains. What unusual kind of stability does this suggest for subtilisin?(b) Subtilisin does have a problem in that it becomes inactivated by oxidation of a methionine close to the active site. Suggest a way to make abetter subtilisin.(c) Is the effect of the N155T mutation what you would expect for a residuethat makes up part of the oxyanion hole? How do the reported values ofkcat and KM support your answer?(d) Assuming that the T155 side chain cannot H-bond to the oxyanion intermediate, by how much (in kJ/mol) does N155 appear to stabilize…
A variant of hemoglobin (Boston variant; mutation His E7(58)α → Tyr) promotes methemoglobin formation involving the α (alpha) subunits. What is the maximum value of the Hill constant (n) that you could measure for the Boston variant of hemoglobin? log (YO2 / 1 - YO2 ) = log pO2 - logP50 Please break down each step of the Hill equation and explain why the result for n is valid from a logical standpoint.
The ESI-MS spectrum in positive ionization mode for lysozyme is obtained. a. What is the molecular weight of the protein to 5 significant figures based on the two highlighted ion species? b. What is the charge of the peaks at 1101.5 and 1789.2.
6. If inhibitor X changes lactase activity to a Vo of 0.333333333333 mM per minute when [S] = 2.0 mM, and a Vo of 0.50 mM per minute when [S] = 3.33333333333 mM, calculate the new Vmax. 1.0 mM per minute 2.0 mM per minute 2.5 mM per minute 5.0 mM per minute 10.0 mM per minute 7. Calculate the new Km of the lactase reaction with inhibitor X. 1.0 mM 2.0 mM 2.5 mM 5.0 mM 10.0 mM 8. Calculate the slope on a Lineweaver-Burk plot (Km / Vmax) for the lactase reaction with inhibitor X. 1.0 per minute 2.0 per minute 2.5 per minute 5.0 per minute 10.0 per minute Inhibitor X exerts which of the following effects on the above enzyme (lactase)? uncompetitive inhibition mixed noncompetitive inhibition competitive inhibition pure noncompetitive inhibition all of the above
Using the ActiveModel for phosphofructokinase (Trypanosoma), describe the difference between the APO1, AP02, and holoenzyme conformations.
The specific activity of a pure preparation of pyruvate kinase (PK) assayed in the direction of pyruvate formation (forward direction) is 220 U/mg at 25 C and at pH 7.5. This form of PK is a homotetramer (MW 240,000) with one active site per subunit. What is the kcat for PK in the forward direction?
From the figure of O2 binding to myoglobin and hemoglobin (ignore the linemarked as T) as described in lecture (shown below) answer the following questions. a) Estimate the P50 for myoglobin from the plot. Show how this estimation isdetermined from the binding curve above. ( The first ghraph) b)Using YO2 = PO2/P50 + PO2 , calculate the fraction of O2 bound for myoglobin at 1 torr. (2nd graph) c)Using the binding curve on the previous page, show how you can estimate whatfraction of hemoglobin is bound near tissues at a pO2 of 30 torr and provide this value. If the pH were lowered, will the amount of O2 bound to hemoglobin at 30 torr increaseor decrease? Explain why this is so based on how this changes hemoglobin structure. If 2,3-BPG were added to the solution, will the amount of O2 bound to hemoglobin at30 torr increase or decrease? Explain why this is so based on how this changes hemoglobinstructure.
Please help me answer and explain these questions: 1. Compare the abundance of A280 chromophores (W, Y, and C) to Bradford sites (loosely R and K) in BSA. 2. We used a protocol that corrects the path length in each well and normalizes the absorbance to the value that would be obtained if the path length were 1 cm (the standard path length). Using this observation and your A280 calibration data, what is your measured e280, for BSA?
In addition to the reactions mentioned in Section 23.5, PLP can catalyze b-substitution reactions. Propose a mechanism for the following PLP-catalyzedb-substitution reaction:

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