**Question 2**An enzyme-catalyzed reaction has a \( K_m = 120 \, \mu M \). At what substrate concentration would this reaction proceed at:i) \( 0.25 \, V_{max} \)ii) \( 0.5 \, V_{max} \)iii) \( 0.75 \, V_{max} \)(Show your calculations; hint – think of \( v_i / V_{max} \)).

In enzyme kinetics, the Michaelis-Menten constant, or Km, is a parameter that characterises the…

Answered: 2. An enzyme-catalyzed reaction has a…

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

4. An enzyme-substrate complex has a Kd = 100 nM. A competitive inhibitor with which of the following Ki values will be most effective at inhibiting this enzyme? A) K₁ = 10 nM B) K₁ = 100 nM C) K₁ = 1000 nM D) None of the above - only the KM is important Briefly explain:
2. Enzyme-catalyzed reactions. Answer the following with true or false. If false, explain why. (a) The initial rate of an enzyme-catalyzed reaction is independent of substrate concentration. (b) At saturating levels of substrate, the rate of an enzyme-catalyzed reaction is proportional to the enzyme concentration. (c) The Michaelis constant Km equals the substrate concentration at which velocity (v) = Vmax/2. (d) The Km for a regulatory enzyme varies with enzyme concentration. (e) If enough substrate is added, the normal Vmax of an enzyme-catalyzed reaction can be attained even in the presence of a noncompetitive inhibitor. (f) The Km of some enzymes may be altered by the presence of metabolites structurally unrelated to the substrate. (g) The rate of an enzyme-catalyzed reaction in the presence of a rate-limiting concentration of substrate decreases with time. (h) The sigmoidal shape of the v versus [S] curve for some regulatory enzymes indicates that affinity of the enzyme for the…
5. For a Michaelis-Menten enzyme, k1 = 5.2 ⅹ 108 M-1 s-1, k-1 = 3.1 ⅹ 104 s-1, and k2 = 3.4 ⅹ 105 s-1. a) Write out the reaction, showing k1, k-1, and k2. Calculate Ks and Km. Does substrate binding approach equilibrium or the steady state? Justify your answer. b) What is kcat for this reaction? Justify your answer. c) Calculate Vmax for the enzyme. The total enzyme concentration is 25 pmol L-1, and each enzyme has two active sites. d) What substrate concentration would be required for the reaction in (c) to reach half of Vmax. Justify your answer mathematically. e) A second Michaelis-Menten enzyme has k1 = 4.2 ⅹ 107 M-1 s-1, k-1 = 6.1 ⅹ 104 s-1, and k2 = 5.3 ⅹ 102 s-1. Which enzyme is most efficient? 6. A pharmaceutical company is trying to develop a
The KM of a Michaelis-Menten enzyme for a substrate is 1.0 x 104 M. At a substrate concentration of 0.20 M, v = 43 μmol/min. Calculate the rate of reaction when the substrate concentration is tenfold lower, 0.020M. 43 μmol min rate of reaction → Vmax Км substrate concentration →
1. Consider the following parameters related to an enzyme that follows Michaelis-Menten kinetics for the reaction: k(1) k(2) S ----> ES ----> P k(-1)
1. A reaction in which a substrate is converted to a product is catalyzed by an enzyme. The reaction was determined to have ket = 10,000. s', KM = 90.0 µM, and a standard Gibbs free energy change of -13.8 kJ mol. Answer the following questions about experiments performed with 2.00 nM enzyme. R= 8.3145 J mol K. !3! a) Calculate the change in free energy for this reaction at room temperature (25.0°C) under the following conditions, and indicate whether the forward reaction is favored or not. i. [(S] = 2.00 µM and [P] = 2.00 nM. !! it. [S] = 2.00 uM and (P) = 2.00 uM.
1. The optimal conditions for salivary lysozyme (hydrolyzing glycoproteins ofbacterial wall) are 37 C- temperature and pH is 5.2. Explain the decrease in this enzyme activity if the temperature will rise up to 60 °C and pH will be changed to 8.0. To answer the question: a) draw the graph of the velocity dependency on temperature and pH; b) calculate the relative enzyme activity if 10 mg of lysozyme catalyzes the formation of 5 uM of the product per 2 minutes. 2 Consider the matic reaction schee: Asnaragine + H20 Aspartate+ NH3:
6. An enzyme catalyzed reaction has a KM of 1 mM and a Vmax of 5 nM/s. What is the reaction velocity when the substrate concentration is (a) 0.25 mM (b) 1.5 mM, and (c) 10 mM?
1) Is the ratio of the forward rate constant and reverse rate constant changed by the presence of an enzyme catalyst? 2) 4) What is the simplest mathematical relationship between substrate concentrations [S], initial velocity (Vo) of an enzyme catalyzed reaction, the maximal velocity of the reaction (Vmax), and the ½ maximal Vo (i.e. Km) ? (Hint: what is the Michaelis-Menten Equation? 3) Graphically illustrate the most useful derivation of the Michaelis-Menton equation (that darn linearized, double-reciprocal)
Which two enzyme curves would be generated from a themophilic bacteria that lives in a strongly acid environment? Please provide a supportive statement about why you picked each of the two curves you picked. Your answer should include information from the graphs. (a) 3 5 MA A 100 7 8 20 2 40 60 Temperature (°C) I 80 ➤ (b) 1 2 3 4 PH 5 6 ➤ 9 10

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

2. An enzyme-catalyzed reaction has a Km = 120 μM. At what substrate concentration would this reaction proceed at: i) 0.25 Vmax, ii) 0.5 Vmax, and iii) 0.75 Vmax? (show your calculations; hint – think of vi/Vmax).