De novo purine biosynthesis is a 10-step pathway that builds the purine rings one atom, or one group of atoms, at a time. Thepathway converts 5-phosphoribosyl-1-pyrophosphate (PRPP) to inosine monophosphate (IMP).Identify the nine intermediates on the pathway diagram.5-phosphoribosyl-1-aminePRPPglycinamide ribonucleotideformylglycinamiderimucloctickeN-succinyl-5-aminoimidazole-4-carboxamide ribonucleotide5-aminoimidazole-4-carboxamide ribonucleotideIncorrect-CH,HHOHGnGlu-CH.H0.CH Hglycine + ATPHNHCHCADP+POHOH OH0-PFIHN(P-RiboseFormy-THFHNTHEHHN-Ribose-ATP6-ⓇCH₂HNHC CH,P-Ribose-ATPADP+PNH,ADP+PHN NH-RiboseNH,N-formylaminoimidazole-4-carboxamide ribonucleotideformylglycinamidineribonuclcotideS-aminoimidazoleribonuclotidieATP ADP+PiHCO,carboxyanincimidazoleribonucleotide-RiboseH-RiboseH₂OFormyl-THF-ASPFumarateHCTHE0N."NH₂Ⓒ-AbseNH,NH,-ATPNH-N-CHCOOADP+PICooIMPCOONH,000Answer Bank

Nucleotides are building blocks of nucleotides. It consists of a nitrogenous base linked to 1'…

Answered: De novo purine biosynthesis is a…

Biochemistry

6th Edition

ISBN:9781305577206

Author:Reginald H. Garrett, Charles M. Grisham

Publisher:Reginald H. Garrett, Charles M. Grisham

Chapter26: Synthesis And Degradation Of Nucleotides

Section: Chapter Questions

Problem 16P

See similar textbooks

Similar questions

In the first step of the aldolase reaction, an active site Lys229 residue, with its side chain amino group in the deprotonated state, acts as a nucleophile and attacks the carbonyl C2 carbon of fructose 1,6-bisphosphate to form a Schiff base (boxed in the scheme). Since the pKa of the Lys side chain amino group in free solution is ~10.5, the pKa of Lys229 side chain must have been perturbed to a (higher lower) value for the enzyme to be active at neutral pH. the answer should include sufficient details, including the definition of pKa.
The reaction catalyzed by phosphorylase is readily reversible in vitro. At pH 6.8, the equilibrium ratio of orthophosphate to glucose 1-phosphate is 3.6. The value of ΔG°’ for this reaction is small because a glycosidic bond is replaced by a phosphoryl ester bond that has a nearly equal transfer potential. However, phosphorolysis proceeds far in the direction of glycogen breakdown in vivo. Suggest one means by which the reaction can be made irreversible in vivo.
Refer to the reaction scheme of the GAPDH catalyzed formation of 1,3-BPG. In the reaction, the nucleophile in step (4) is an inorganic phosphate molecule. The enzyme active site is elaborately constructed so that inorganic phosphate, not water, acts as the nucleophile. What advantage is gained by using inorganic phosphate, instead of water, as the nucleophile? Discuss in terms of the energy yield of glycolysis. No need to calculate the total net energy yield of glycolysis.
#1 Specify the role each of the following amino acids play within the crystal structure and/or active site for Be as specific as possible, with pictures (and mechanistic arrows) as necessary. His11 Arg140 Glu89 Trp68 #2 Provide a step-wise mechanism for the reaction Bisphosphoglycerate mutase catalyzes, using the amino acids responsible for aiding in catalysis. You do not need to add surrounding amino acids that aid in substrate specificity. (drawn out)
uizzes/67365/take Based on the image below, select the correct statements. Note: There may be more than 1 correct response. I Ribose 5-phosphate ribose phosphate pyrophosphokinase (PRPP synthetase) glutamine-PRPP amidotransferase adenylosuccinate synthetase AMP > 5-Phosphoribosylamine I adenylosuccinate PRPP lyase 9 steps Adenylosuccinate AMP IMP <-- ADP - AMP <-- GMP <-- IMP IMP dehydrogenase <- GMP - XMP ADP ATP GMP يمد XMP-glutamine amidotransferase Increased levels of ADP inhibit the production of PRPP. Increased levels of GMP inhibit the production of XMP. O Increased ADP activates PRPP synthase to increase PRPP levels. Increased IMP activates glutamine-PRPP amidotransferase to further increase IMP levels. 8 OBC
When hyaluronan synthase from Pasteurella multocida was expressed in E. coli, the bacteria spun out a capsule of hyaluronan. This reaction was analyzed using purified membrane fragments containing the hyaluronan synthase, a radio-labeled tetrasaccharide acceptor (Part A), along with the activated forms of the sugar subunits: UDP-N-acetylglucosamine and UDP-glucuronic acid. In short incubations with the complete mixture, the tetrasaccharide primer elongated by several units, although only odd-numbered chains were visible (Part B lane 2). If one or both activated sugars were left out, the results shown in lanes 3-5 (Part B) were obtained. Why do you suppose that only odd-number chains are visible in your assay? (A) ACCEPTOR nonreducing end HO- HO OH COO glucuronic acid (GICUA) HO- CH3 T C=O I NH CH₂ OH N-acetylglucosamine (GlcNAc) COO но- HO OH OH I CH₂ reducing end NH C=O CH3 Choose one: O A. Synthase adds GlcNAc much more slowly than it adds GICUA. O B. One of the monosaccharide…
Consider the role of Histidine in the Serine protease mechanism and sketch a plot showing the predicted pH profile of chymotrypsin which has a pH optimum of approximately ~8. The pk, for the His in the catalytic triad is 7.3 in free chymotrypsin which increases to greater than 8 with a bound peptide. Be sure to label the plot axes and indicate the pka of His on the plot,
The mechanism of chymotrypsin can be viewed as a two-step process, acylation of the enzyme active site followed by a deacylation reaction. What accounts for the observed "burst" in rapid kinetic studies of the hydrolysis of N-acetyl-L-phenylalanine p-nitrophenyl ester by chymotrypsin? The rate of hydrolysis of the acyl-enzyme intermediate is faster than the rate of forming the acyl-enzyme intermediate. The rates of the acylation and deacylation reactions are equal. The rate of the acylation reaction is slower than the rate of the deacylation reaction. The rate of the acylation reaction is faster than the rate of the deacylation reaction.
The enzyme aspartate transcarbamoylase catalyzes an early step in pyrimidine biosynthesis. The two states of the multi-subunit enzyme are shown below. Note that the binding of the regulatory molecule CTP (cytosine triphosphate) causes the enzyme complex to be inactive. Is this situation an example of positive or negative regulation? Explain why the use of CTP as the regulatory molecule is logical givén the overall function of this particular enzyme. INACTIVE ENZYME: T STATE catalytic subunits regulatory subunits OFF 6 CTP ON ACTIVE ENZYME: R STATE
A mutant form of polypeptide hormone angiotensin II has the amino acid composition (Asp, Arg, Ile, Met, Phe, Pro, Tyr, Val) The following observations are made: Trypsin yields a dipeptide containing Asp and Arg, and a hexapeptide with all the rest. • Cyanogen bromide cleavage yields a dipeptide containing Phe and Pro, and a hexapeptide containing all the others. • Chymotrypsin cleaves the hormone into two tetrapeptides, of composition (Asp, Arg, Tyr, Val) and (Ile, Met, Phe, Pro) • The dipeptide of composition (Pro, Phe) cannot be cleaved by either chymotrypsin or carboxypeptidase. What is the sequence of angiotensin II?
ATCase catalyzes the conversion of carbamoyl phosphate and aspartate into N-carbamoylaspartate, a precursor in pyrimidine biosynthesis. What roles do ATP and CTP play in this reaction? uncompetitive inhibitors heterotropic modulators homotropic modulators mixed inhibitors
Based on the image below, select the correct statement HN Aspartate Rib-P Inosinate (IMP) IMP H₂O OOC-CH₂- COO NH Fumarate N 274 adenylosuccinate lyase Rib-P Adenylosuccinate GTP GDP + P₁ adenylosuccinate IMP synthetase NAD+ NADH + H+ dehydrogenase Figure 22-36 Lehninger Principles of Biochemistry, Sixth Edition ©2013 W. H. Freeman and Company H HN H -N Gin Rib P Xanthylate (XMP) NH₂ Rib P Adenylate (AMP) Glu ATP AMP + PP₁ XMP-glutamine amidotransferase HN H₂N O GTP is phosphorylated in the conversion of IMP to GMP GTP is phosphorylated in the convertion of IMP to AMP GTP is dephosphorylated in the conversion of IMP to GMP O GTP is dephosphorylated in the conversion of IMP to AMP Rib-P Guanylate (GMP) GMP

SEE MORE QUESTIONS

Recommended textbooks for you

Biochemistry

ISBN:

9781305577206

Author:

Reginald H. Garrett, Charles M. Grisham

Publisher:

Cengage Learning

Biochemistry

ISBN:

9781305577206

Author:

Reginald H. Garrett, Charles M. Grisham

Publisher:

Cengage Learning

SEE MORE TEXTBOOKS

De novo purine biosynthesis is a 10-step pathway that builds the purine rings one atom, or one group of atoms, at a time. The pathway converts 5-phosphoribosyl-1-pyrophosphate (PRPP) to inosine monophosphate (IMP). Identify the nine intermediates on the pathway diagram.