Please answer in detail. Thanks. The enzyme dihydroneopterin aldolase (DHNA) is found in the metabolic pathway leading to folic acid. The enzyme catalyzes the reactionbelow, the conversion of 7,8-dihydroneopterin (DHNP) to 6-hydroxymethyl-7,8-dihydropeterin (HP) and glycoaldehyde (GA), the third stepin the biosynthetic path to folic acid. The enzyme also catalyzes the epimerization of 7,8-dihydroneopterin to 7,8-dihydro-L-monopterin(DHMP). Provide a chemical mechanism that can account for the formation of both of these products. Be sure to show the involvement ofenzyme residues that might facilitate each step in the mechanism.HNH₂NOHDHNPOHOHHNH₂NDHMPHNH₂NHPOHÕHOHOH+GAOH

DHNA can catalyze two types of reactions;aldolase cleavage of DHNP to HP & GA andepimerization…

Answered: The enzyme dihydroneopterin aldolase…

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

A glycolytic intermediate may be used to make the glycerol 3-phosphate necessary for the production of glycerophospholipids. For this conversion, provide a reaction sequence.
Aldolase is a key enzyme in glycolysis that catalyzes the cleavage of its substrate, fructose-1,6-bisphosphate, into glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. The lysine and tyrosine shown are enzyme residues essential in the presented mechanism. Pi indicates inorganic phosphate. a. Which residue, if any, is acting as a general acid in the mechanism shown above? Explain your choice. b Which of the following type(s) of catalysis is/are involved in the mechanism above? Covalent catalysis Metal ion catalysis General acid/base catalysis none of the above c. Scientists prepared a mutant of aldolase in which tyrosine was replaced with serine. They found that the KM value for fructose-1,6-bisphosphate remained the same in the mutant as the original wild type (WT) enzyme. The value of kcat, however, decreased by a factor of 1000. Would Vmax be altered for the mutant enzyme? If so, by how much? Explain your answer. Would deltaG of the reaction be altered for the…
Triosephosphate isomerase (TIM) catalyzes the conversion of dihydroxyacetone phosphate to glyceraldehyde-3-phosphate. The enzyme’s catalytic groups are Glu 165 and His 95. In the first step of the reaction, these catalytic groups function as a general-base and a general-acid catalyst, respectively. Propose a mechanism for the reaction.
Ethylene glycol (HO−CH2−CH2−OH) is a major component of antifreeze. In the body, it is first converted to HOOC−CHO (oxoethanoic acid) and then to HOOC−COOH (oxalic acid), which is toxic. What class of enzyme catalyzes both of the reactions of ethylene glycol? The treatment for the ingestion of ethylene glycol is an intravenous solution of ethanol. How might this help prevent toxic levels of oxalic acid in the body?
There is another class of aldolase enzymes known as Class II. These enzymes are found in fungi, algae, and some bacteria. This class differs for Class I in that these enzymes do not have a Lys residue associated with their active sites, but contain a divalent cation (usually Zn2+ or Fe2+) in the active site. Outline a possible mechanism for a Class II aldolase and explain the function of the metal ion in the reaction.
If we look at the free energy changes caused by phosphate hydrolysis in the following list of phosphorylated substances, we see 2,2-Phosphatidylinositol (2,2-Phosphatidylinositol) and 2,2-Phosphatidylinositol (2,2-Phosphatidylinositol) Which of these compounds can be directly produced by the transfer of a phospho-group from ATP, given the -7.3 kcal/mole free energy change? 1,3-bisphosphoglycerate Glucose-6-phosphate Compounds with phosphorylation in their name. PEP Glucose-1-phosphate
Glyphosate, which inhibits the EPSP synthase reaction of the shikimic acid pathway, is a phosphonic acid derivative of glycine; hence its name (glycine phosphonate). Based upon your knowledge of the EPSP synthase reaction (see pages 908–909), would you expect the inhibition to be competitive or noncompetitive with respect to each of the substrates? Briefly explain your answer.
The glutamate dehydrogenase (GDH) catalyses the following reaction: +H₂N- H - - CH₂ - CH₂ COO acide glutamique COO™® + NAD+ + H₂O GDH COO C: CH₂ CH₂ COO™ O + NH4+ NADH + H* The activity of GDH is monitored in the sense of the formation of glutamate using the following conditions: -0.2 mL of 5 M ammonium sulphate 2.4 mL of buffer at pH 8 0.1 mL of NADH at 6.15 mg.mL-¹ (M = 709 g.mol-¹) 0.2 mL of 1 M a-ketoglutarate solution Warm mixture at 25 °C for 5 min - Add 0.1 mL of GDH solution containing 1.6 mg.mL-¹protein to start the reaction. acide a-cétoglutarique The change in absorbance at 340 nm is monitored, in a 1-cm cuvette, every minute for 10 min. Results are given in the table below: Data: ENADH at 340 nm = 6220 M¹.cm¹ Time (min) 1 2 3 4 5 6 7 8 9 1.760 1.718 1.675 1.635 1.595 1.550 1.510 1.489 1.476 A340 10 1.451 - Draw the graph A = f(t). Calculate A340 at t = 0 and place this point on the curve. - Comment the shape of the curve, particularly the portion that corresponds to a…
Thiamine is the vitamin precursor for a co-enzyme called thiamine pyrophosphate or TPP. A patient diagnosed with thiamine deficiency exhibited fatigue and muscle cramps. The muscle cramps have been related to the accumulation of specific metabolic acids. On the following list, circle the metabolic acids that are most likely to accumulate in a thiamine deficiency? Note: There may be more than one. Isocitrate Pyruvate Succinate α-ketoglutarate Malate Fumarate (b) Provide a brief explanation for your answer to 1 (a) here
Prostaglandins are a class of eicosanoids, fatty acid derivatives with a variety of extremely potent actions on vertebrate tissues. They are responsible for producing fever and inflammation and its associated pain.Prostaglandins are derived from the 20-carbon fatty acid arachidonic acid in a reaction catalyzed by the enzyme prostaglandin endoperoxide synthase. This enzyme, a cyclooxygenase, uses oxygen to convert arachidonic acid to PGG2 , the immediate precursor of many different prostaglandins .(a) The kinetic data given below are for the reaction catalyzed by prostaglandin endoperoxide synthase. Focusing here on the first two columns, determine the Vmax and Km of the enzyme. (b) Ibuprofen is an inhibitor of prostaglandin endoperoxide synthase. By inhibiting the synthesis of prostaglandins, ibuprofen reduces inflammation and pain. Using the data in the first and third columns of the table, determine the type of inhibition that ibuprofen exerts on prostaglandin endoperoxide synthase.
The enzyme ATCase (Aspartate TransCarbamoylase) catalyzes an early step in the synthesis of the pyrimidine nucleotides. The activities of the ATCase reactions are shown in the following plots. Which one of the following statements is most correct description about this enzyme and/or this enzyme-catalyzed reaction? ATP No allosteric effectors Vo CTP ATCase 10 20 30 40 (Aspartate] (mM) O A. This enzyme is allosterically inhibited by ATP. B. This enzyme is composed of multiple subunits. C. "ATP" binds to catalytic subunits of ATCase. O D."CTP" binds to the R-state enzyme. O E. At high concentrations of ATP, ATP binds to the T-state enzyme, thus increase the affinity for the substrate [S].
Prostaglandins are a class of eicosanoids, fatty acid derivatives with a variety of extremely potent actions on vertebrate tissues. They are responsible for producing fever and inflammation and its associated pain. Prostaglandins are derived from the 20-carbon fatty acid arachidonic acid in a reaction catalyzed by the enzyme prostaglandin endoperoxide synthase. This enzyme, a cyclooxygenase, uses oxygen to convert arachidonic acid to PGG2, the immediate precursor of many different prostaglandins. Arachidonic Rate of formation Rate of formation of PGG2 with 10 mg/ml acid (mM) of PGG2 (mM/min) ibuprofen (mM/min) 0.280 15.3 9.58 0.336 17.3 11.0 0.504 21.8 14.8 0.840 27.6 20.3 1.96 35.8 29.8 The kinetic data given in the table are for the reaction catalyzed by a mutant of prostaglandin endoperoxide synthase. Focusing here on the first two columns, determine the Vmax and Km of the enzyme. mM/min Vmax %3D

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