Which of the following statements is true about effect of substrate concentration on enzymeactivity ?The rate of reaction increases as the substrate concentration increases up to certainlimit at which the reaction rate is maximal (Vmax.)At Vmax, the enzyme is completely saturated with the substrate,At Vmax, any increase in substrate concentration don't affect the reaction rate.All of them

The formation of an enzyme-substrate complex is the first step in enzymatic catalysis. The enzyme…

Answered: Which of the following statements is…

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

An allosteric enzyme that follows the concerted mechanism has a T/R ratio of 500 in the absence of substrate. Suppose that a mutation reversed the ratio. How would this mutation affect the relation between the rate of the reaction and substrate concentration? The mutant enzyme would behave like an enzyme that obeys Michaelis Menton kinetics. The mutant enzyme would have a smaller vmax There would be no difference in the mutant enzyme in terms of substrate binding and catalysis. More than one answer is correct. The mutant enzyme would display cooperativity more than the wild type. MacBook Air 888 F5 F4 F3 F2 %23 2$ %
Which statements are false? Initial velocities of enzyme reactions are best obtained in the absence of product because it simplifies analysis. Initial velocities refer to the velocity of the reaction right after it is initiated. The velocity of the reaction as a function of measuring time are curved just like an isothermal binding curve because of substrate binding to the enzyme. Initial velocities correspond to the pre-steady state condition for free enzyme. Initial velocities can sometimes be measured by spectroscopy such as UV/Vis spectroscopy when monitoring the production of NADH from NAD+. The velocity of the reaction will eventually go to zero. The reaction will reach equilibrium because of the presence of the enzyme. It is always better to use substrate rather than product to measure enzyme kinetics.
Inhibitor X exerts which of the following effects on the above enzyme (lactase)? (inhibitor X changes lactase activity to a Vo of 0.10 mM per minute when [S] = 1.0 mM, and a Vo of 0.133333333333 mM per minute when [S] = 2.0 mM) pure non-competitive inhibition uncompetitive inhibition competitive inhibition all of the above none of the above
on When testing the effect of substrate concentration on the reaction rate, there comes a point at which increasing the substrate concentration has no effect on the reaction rate. That is, the reaction rate remains the same and no longer increases. Which of the statements below would explain this? Select one: O A. The enzyme is denatured OB. The substrate is denatured OC. All available enzymes are saturated or full with substrates. OD. The enzyme concentration is too high
an enzyme acts on a substrate X. The enzyme exists in four different forms, with different catalytic efficiencies. The table shows the kcatand KM values for each form of the enzyme. If the concentration of substrate X in a solution is 5 µM, which of the four forms of the enzyme is the most efficient? Form of Enzyme kcat (s-1) KM (µM) A 50 10 B 50 1 C 100 4 D 1000 100 a. Form A b. Form B c. Form D d. Form C
Which of the following statements regarding enzyme catalysis is false? All options are false. Once formed, the transition state slowly proceeds to forming the product at a rate determined by cofactor binding The free energy of binding of the enzyme to the transition state is more favorable than the free energy of binding of the enzyme to the substrate The substrate and active site of the enzyme are solvated to promote enzyme-substrate interaction Once formed, the product dissociates from the enzyme after ATP hydrolysis in order to regenerate the active site
A purely competitive inhibitor of an enzyme has which of the following kinetic effects? decrease in Km increase in Vmax decrease in Vmax increase in Km Question 60 The Michaelis-Menten constant (KM) has the following characteristics, EXCEPT: The dimension for KM is concentration, such as molarity It is equal to ½ of Vmax It is the substrate concentration necessary to reach ½ of Vmax
Consider the Michaelis-Menten equation, below: Vmaz (S V. k + [S] %3D What is the relationship between changes in substrate concentration and velocity when the concentration of substrate, [S), is well below k7 The S terms cancel out in this equation, so there is no effect of changing substrate concentration. The S] term in the numerator is negligible, so there is no impact of changing substrate concentration. Because the enzyme has reached Vr there is no effect of changing substrate concentrations on enzyme velocity. OThe [S term in the denominator is negligible compared to k There is a linear relationship between substrate concentration and velocity.
Which of the following statements are true about enzyme regulation via noncovalent interactions? Select all that apply. Molecules can cause a change in enzyme shape because they're able to bind to the enzyme somewhere other than the active site The function of an enzyme is altered by a chemical change in its primary structure, which is called phosphorylation Molecules that are similar to the substrate in both size and shape can compete with the substrate for access to the enzyme's active site Molecules that are similar to the substrate in both size and shape can compete with the substrate for access to a location other than the active site
When enzyme solutions are heated, there is a progessive loss of catalytic activty over time due to denaturation of the enzyme. A solution of the enzyme hexokinase incubated at 45 degrees Celsius lost 50% of its activity in 12 minutes, but when incubated at 45 degrees Celsius in the presence of a very large concentration of one of its substrates, it lost only 3% of its activity in 12 minutes. Suggest why thermal denaturation of hexokinase was retarded in the presence of one substrates.
Which of the following statements regarding enzymes and transition states is true? stabilization of the transition state must be less than stabilization of ES for catalysis to occur binding of substrate to an enzyme often causes strain, thus promoting transition state formation the transition state conformation of an enzyme catalyzed reaction is identical to the conformation seen in the uncatalyzed transition state formation of the transition state always assures that the reaction will proceed to product none of the above are true
Enzyme X follows Michaelis-Menten kinetics. You add an inhibitor to your enzyme and you notice that the Vmax has decreased while the Km for enzyme X has increased as a result of adding the inhibitor. What are you able to conclude from this information? The inhibitor must be competitive The amount of total enzyme available to catalyze the reaction in the presence of the inhibitor has likely decreased The enzyme has a higher affinity for its substrate in the presence of the inhibitor The substrate concentration required to reach 1/2 of the maximum velocity for this enzyme has increased as a result of the inhibitor More than one of the above are conclusions that can be drawn from this information

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