Please answer a and b both 3. Researchers purified a new enzyme and during an initial characterization determined the Vmax to be 2.8 µM/s and theKm to be 25 µM for reactions performed using 2.0 nM enzyme. After further purification, they realized that there wasan inhibitor present in their original experiment. After the inhibitor was removed the Vmax increased to 4.8 µM/secand the Km is now 15 µM.a. Calculate the values for a and a'.α=a' =b. If the concentration of inhibitor was determined to be 1.82 µM in the original experiment, determine the Kiand/or K₁'."K₁=K₁' =

Enzyme inhibition is when an inhibitor bind to the enzyme at the active site or another site, which…

Answered: 3. Researchers purified a new enzyme…

Biochemistry

9th Edition

ISBN:9781319114671

Author:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Publisher:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Chapter1: Biochemistry: An Evolving Science

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

1. Enzyme X has a molecular weight of 35,000 Da. When this enzyme is assayed for enzyme activity, the corresponding line of the double reciprocal plot has the equation y = 75,253X + 102,392. The substrate concentration was in mM and the velocity was measured in mM min". From these data calculate the following: a. KM and Vmax b. kcat if the enzyme concentration was 2 mg/mL. 2. When you run enzyme X from question one on an SDS-PAGE you find that, after Coomassie staining, there is only one band on the gel that runs just below the 20,000 Dalton molecular weight marker. What does this result tell you about the nature of the quaternary structure of your enzyme?
3.An enzyme catalyzed reaction is studied and the following kinetic analysis is obtained: |[S), mM 0.050 0.075 v, (µM min") 0.93 1.264 1.77 2.14 3.7 0.125 0.175 0.935 a. Using Excel, make a fully labeled Lineweaver-Burk plot and determine the Km and Vmax for the enzyme b. The reactions were set up dissolving 1 mg of the enzyme (MW= 100000 Da) in 100 ml of final reaction buffer. Determine the turnover number for the enzyme assuming 1 active site exists per enzyme molecule? c. Determine the catalytic efficiency for the enzyme d. The same reactions are performed in presence of an inhibitor A and the resulting velocities determined: v plus inhibitor, (µM min) 0.272 0.37 0.518 0.626 |1.08 |[S), mM 0.050 0.075 0.125 0.175 0.935 Plot these data on the same graph as above and determine the new Km and Vmax and the type of inhibitor (competitive, non-competitive). e. Can the effects of the inhibitor be over-ridden by adding more substrate? Why?
A purified protein sample was used in a reaction, resulting in an activity of 696.7 nmol min-1. The reaction volume was 145.0 µL and the final volume before loading the plate was 1,050 µL. The total reaction time was 4.25 min. The amount of protein used in the reaction was 4.270 µg. Calculate the specific activity of the sample (in nmol min-1 µg-1).
you are trying to come up with a drug to inhibit the activity of an enzyme thuogth to have a role in a liver disease. in the lab the enzyme was shown to have a Km of 1x10-6 M and Vmax of 0.1 micromoles/min.mg measruing at room temperature. you developed a mixed non-competitve inhibitor with a ki=0.4x10-6M and a Ki` pf 0/2 x 10-5 What will be the apparent Km in the presence of 1.0x10-6 M?
1. A Lineweaver-Burk Plot is shown below. 30 25 Curve A y = 3.1207x + 2.4978 20 15 Curve B y = 1.0003x + 2.3602 10 5 -3 1 5 7 11 1/[Catechol] (mM1) With these curves, determine the following enzyme parameters. Show all pertinent solutions. a. Km of Curve A and Curve B b. Vmax of Curve A and Curve B c. Assuming that one of these curves corresponds to the kinetics of one enzyme and one substrate, which curve represents the effect of an inhibitor? Why do you say so? d. What type of inhibition is exhibited by your answer in question c? Why do you say so? 1/V, (units of activity 1)
2. Using 3 umol of a novel enzyme in a set of kinetics experiments resulted in a kcat of 79 min and a KM of 87 µM. Draw relatively accurate Michaelis-Menten and Lineweaver-Burk plots (using kcat for the M-M plot and Vmax for the L-B plot) for the enzyme. Label the axes clearly and completely.
2) Below are kinetic data at three different inhibitor concentrations. Graph the data in an appropriate form to determine whether the inhibitor is competitive or uncompetitive. a (μm) 0.4 0.67 1.00 2.00 v (μM/min) (no inhibitor) 0.22 0.29 0.32 0.40 v (μM/min) (10 nM inhibitor) 0.21 0.26 0.30 0.36 v (μM/min) (20 nM inhibitor) 0.20 0.24 0.28 0.32
1. Lyticase is an enzyme that breaks down cell membranes. It is particularly useful when harvesting proteins made in yeast or bacteria cells. In a series of 6 experiments, lyticase was used to break down cells at 40 °C, using different substrate concentrations. Determine the parameters from the Michaelis-Menten equation, Km and Vmax, for the reaction with data given below: (A) use a Lineweaver-Burk plot (B) use an Eadie-Hofstee plot (C) use a Hanes-Woolf plot (see textbook) [S], mmol/L 8.400 2.310 1.290 0.630 0.201 0.0720 reaction? v, mmol/(L-min) 0.0343 0.0254 0.0192 0.0140 0.00620 0.00250 (D) Which of the substrate concentrations used in the experiments above would achieve closest to a zero-order Note: when doing a trendline curve fit for data, if the equation coefficients show up with less than 3 significant figures (the slope and intercept), you should adjust the trendline equation format to switch to scientific or number with enough places after the decimal to get an accurate…
4. Below is a Michaelis-Menten plot for a wild-type (WT) and mutant (V105A) enzyme isolated from the bacterium Staphylococcus aureus. The enzyme is involved in carbohydrate metabolism and is a potential biocatalyst for the large-scale production of rare sugars. (8) mg V₂ μmol s1 1.50- 1.25- 1.00- 0.75- 0.50- 0.25- 0.00 0 100 200 300 [s], mM 400 500 WT (a) Estimate the KM and Vmax for the wild-type and mutant enzyme from the graph. V105A (b) Calculate the keat and keat/KM for the wild-type and mutant enzyme based on your estimated values in (a) if the total enzyme concentration is 0.5 µmol/mg. (c) Is the mutant enzyme a more or less efficient catalyst than the wild-type enzyme? Briefly explain.
An enzyme-catalyzed reaction has a KM of 20.0 mmol L-1 and Vmax of 17.0 pmol s-1. When a mixed inhibitor is added, the apparent KM is 50.0 mmol L-1 and the apparent Vmax is 5.20 pmol s-1. Calculate α.
You are trying to come up with a drug to inhibit the activity of an enzyme thought to have a role in liver disease. In the laboratory the enzyme was shown to have a Km of 1.0 x 10-6 M and Vmax of 0.1 micromoles/min.mg measured at room temperature. You developed a competitive inhibitor. In the presence of 5.0 x 10-5 M inhibitor, the apparent Km of the enzyme was found to be 1.5 x 10-5 M. What is the Ki of the inhibitor?
1. Penicillin is hydrolyzed and thereby rendered inactive penicillinase, an enzyme present in some penicillin-resistant bacteria. The molecular weight of this enzyme in Staphylococcus aureus is 29.6 kilo Daltons (29.6 kg/mole or 29,600 g/mole or 29,600 ng/nmole) The amount of penicillin hydrolyzed in 2 minute in a 10-mL solution containing 109 g (1 ng) of purified penicillinase was measured as a function of the concentration of penicillin. Assume that the concentration of penicillin does not change appreciably during the assay. [Hint: Convert everything to the same concentration terms] Show all calculations and include spreadsheets and graphs to determine Km, Vmax and kcat for this enzyme. Make sure your final answers have correct units. [Another hint: Note that [S] and amount hydrolyzed are already in concentration terms. So you don't need to worry about the volume for calculating [S] and V. ] Penicillin concentration (microM) Amount hydrolyzed (nanoM) 1 110 3 250 5 340 10 450 30 580…

SEE MORE QUESTIONS

Recommended textbooks for you

Biochemistry

ISBN:

9781319114671

Author:

Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Publisher:

W. H. Freeman

Lehninger Principles of Biochemistry

Biochemistry

ISBN:

9781464126116

Author:

David L. Nelson, Michael M. Cox

Publisher:

W. H. Freeman

Fundamentals of Biochemistry: Life at the Molecul…

Biochemistry

ISBN:

9781118918401

Author:

Donald Voet, Judith G. Voet, Charlotte W. Pratt

Publisher:

WILEY

Biochemistry

ISBN:

9781319114671

Author:

Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Publisher:

W. H. Freeman

Lehninger Principles of Biochemistry

Biochemistry

ISBN:

9781464126116

Author:

David L. Nelson, Michael M. Cox

Publisher:

W. H. Freeman

Fundamentals of Biochemistry: Life at the Molecul…

Biochemistry

ISBN:

9781118918401

Author:

Donald Voet, Judith G. Voet, Charlotte W. Pratt

Publisher:

WILEY

Biochemistry

ISBN:

9781305961135

Author:

Mary K. Campbell, Shawn O. Farrell, Owen M. McDougal

Publisher:

Cengage Learning

Biochemistry

ISBN:

9781305577206

Author:

Reginald H. Garrett, Charles M. Grisham

Publisher:

Cengage Learning

Fundamentals of General, Organic, and Biological …

Biochemistry

ISBN:

9780134015187

Author:

John E. McMurry, David S. Ballantine, Carl A. Hoeger, Virginia E. Peterson

Publisher:

PEARSON

SEE MORE TEXTBOOKS