To review:
The type of inhibition by A and B inhibitor and the kind of affinity they possess for ES versus E.
Introduction:
Enzyme inhibitors are the molecules that are able to bind to enzyme and reduce the activity. Enzyme inhibitors work by several ways such as preventing the substrate from entering the active site of an enzyme or hinder in catalyzing the reaction. There are three types of enzyme inhibitors, namely, competitive, noncompetitive, and uncompetitive.
Explanation of Solution
The velocity of the reaction at different substrate concentrations in presence of A inhibitor and B inhibitor are given in the question. For calculating, the Vmax (maximum
[S] in mM (millimolar) |
V | |
|
1.3 | 1.17 | 0.76 | 0.855 |
2.6 | 2.10 | 0.38 | 0.476 |
6.5 | 4.00 | 0.15 | 0.25 |
13.0 | 5.70 | 0.077 | 0.175 |
26.0 | 7.20 | 0.038 | 0.139 |
The following table shows the values of [S], V,
[S] in mM (millimolar) |
V | |
|
1.3 | 0.62 | 0.76 | 1.613 |
2.6 | 1.42 | 0.38 | 0.704 |
6.5 | 2.65 | 0.15 | 0.377 |
13.0 | 3.12 | 0.077 | 0.321 |
26.0 | 3.58 | 0.038 | 0.28 |
Plotting the graph between
According, to the Michelis Menten equation, the value of y-intercept represents
From the graph, it can be observed that the value of y-intercept is 0.10 mM-1 sec. y-Intercept represents inverse of Vmax.
KM can be calculated by putting the value of Vmax in the equation Slope=KM/Vmax
So, the KM for the reaction is 9.8and the Vmax is 10 mM. sec-1. In presence of inhibitor A, KM is changed but Vmax is unchanged. So, it is a competitive inhibitor.
According, to the Michelis Menten equation, the value of y-intercept represents
From the graph, it can be observed that the value of y-intercept is 0.25 mM-1 sec. y-Intercept represents inverse of Vmax.
KM can be calculated by putting the value of Vmax in the equation Slope=KM/Vmax
So, the KM for the reaction is 5.68 and the Vmax is4 mM. sec-1. In presence of inhibitor B, KM andVmax both are changed. So, it is anuncompetitive inhibitor. A inhibitor is a competitive inhibitor so it can bind to free enzyme and has no affinity for ES. B inhibitor is an uncompetitive inhibitor, so it can bind to ES as well as E.
Therefore, it can be concluded that inhibitor A is competitive as Vmax remain unchanged whereas, inhibitor B is uncompetitive inhibitor. A can bind to free enzyme and B can bind to E as well as ES.
Want to see more full solutions like this?
Chapter 6 Solutions
Biochemistry: The Molecular Basis of Life
- _____________ pathways can function in both anabolic and catabolic processes.arrow_forwardThe following phenylboronate is a competitive inhibitor of a chymotrypsin-like enzyme. Unlike carbon, boron is quite happy to be bonded to three oxygens (and one carbon)—explain why this feature makes it a much better inhibitor than the corresponding carboxylic acid (which is quite ineffective).arrow_forwardThe inhibitory effect of an uncompetitive inhibitor is greater at high [S] than at low [S]. Explain this observation.arrow_forward
- Question 1. a) Explain how 5 specific fatty acids ultimately generate specific classes of prostaglandins and leukotrienes that are involved in blood pressure, platelet aggregation and inflammation.b) Indicate and explain the specific effects of each of these classes of prostaglandins and leukotrienes on blood pressure, platelet aggregation and inflammation.c) Identify which foods, functional foods and nutraceuticals provide one or more of these 5 fatty acids.arrow_forwardWhy is trypsin an unusual name for an enzyme? (What is the convention for enzyme names?) .arrow_forwardThe amino acids glutamine and glutamate are central toamino acid metabolism. Explain.arrow_forward
- Propose a plausible enzyme mechanism for triose kinase, the enzyme that catalyzes the conversion of glyceraldehyde to glyceraldehyde-3-phosphate. You may use "B:" for a general base amino and "H-A" for a general acid amino acid if needed.arrow_forwardGive an example of a noncompetitive inhibitor and its target enzyme. Draw a hypothetical Michaelis-Menten curves in the presence and absence of the noncompetitive inhibitor. Discuss the effects of noncompetitive inhibition and the reasons for these effects on the values of Km and Vmax.arrow_forwardIn order to function as an oxidative phosphorylation uncoupler, 2,4-dinitrophenol must act catalytically, not stoichiometrically. What does this mean? Identify and discuss an important implication of this conclusion.arrow_forward
- What method and conditions (provide detail) do you propose to measure the Specific Activity of the enzyme chymotrypsin?arrow_forwardUsing the appropriate graph and table above, explain what the N426S mutation appears to be doing to the enzyme’s function. Discuss the kinetic parameter changes and their meaning in this context, not the structure of the enzyme, which was not given to you.arrow_forwardWhat are catalases? Why are they called antioxidant enzymes? Give the industrial applications of this enzyme.arrow_forward
- BiochemistryBiochemistryISBN:9781319114671Author:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.Publisher:W. H. FreemanLehninger Principles of BiochemistryBiochemistryISBN:9781464126116Author:David L. Nelson, Michael M. CoxPublisher:W. H. FreemanFundamentals of Biochemistry: Life at the Molecul...BiochemistryISBN:9781118918401Author:Donald Voet, Judith G. Voet, Charlotte W. PrattPublisher:WILEY
- BiochemistryBiochemistryISBN:9781305961135Author:Mary K. Campbell, Shawn O. Farrell, Owen M. McDougalPublisher:Cengage LearningBiochemistryBiochemistryISBN:9781305577206Author:Reginald H. Garrett, Charles M. GrishamPublisher:Cengage LearningFundamentals of General, Organic, and Biological ...BiochemistryISBN:9780134015187Author:John E. McMurry, David S. Ballantine, Carl A. Hoeger, Virginia E. PetersonPublisher:PEARSON