(a)
Interpretation:
6-phosphoglucono-⏹-lactone should be identified.
Concept introduction:
6-phosphoglucono-⏹-lactone is formed during the pentose phosphate pathway. In the first step of pentose phosphate pathway, dehydrogenation of glucose-6-phosphate at C-1 takes produce 6-phosphoglucono-⏹-lactone.
Answer to Problem 28P
The compound C in the reaction is 6-phosphoglucono-⏹-lactone.
Explanation of Solution
6-phosphoglucono-⏹-lactone is an intramolecular ester formed by the reaction of C-1 carboxyl group and C-5 hydroxyl group. It is formed by dehydrogenation of C-1 carbon of Glucose-6-phosphate. Hydroxyl group at C-1 of glucose-6-phosphate is converted to carbonyl group. Therefore, the structure of 6-phosphoglucono-⏹-lactone is (C).
(b)
Interpretation:
The reactions producing NADPH should be determined.
Concept introduction:
Two molecules of NADPH are produced duringthe oxidative phase of pentose phosphate pathway.
Answer to Problem 28P
The reactions B and F produce NADPH.
Explanation of Solution
First NADPH is produced when the C-1 in glucose-6-phosphate is dehydrogenated into 6-phosphoglucono-⏹-lactone by glucose-6-phosphate dehydrogenase. This 6-phosphoglucono-⏹-lactone is hydrolyzed by a lactonase resulting 6-phosphogluconate. This 6C sugar acid is then decarboxylated by 6-phosphogluconate dehydrogenase into ribulose-5-phosphate. In this step also NADP+ acts as the electron acceptor and produce NADPH.
Therefore,reactions B and F produces NADPH.
(c)
Interpretation:
Ribulose-5-phosphate should be identified.
Concept introduction:
Ribulose-5-phosphate is the productof pentose phosphate pathway.
Answer to Problem 28P
The compound G in the reaction is Ribulose-5-phosphate.
Explanation of Solution
As the first step of oxidative phase of pentose phosphate pathway, C-1 of glucose-6-phosphate is dehydrogenated into 6-phosphoglucono-⏹-lactone by glucose-6-phosphate dehydrogenase. Then this 6-phosphoglucono-⏹-lactone is hydrolyzed by a lactonase resulting 6-phosphogluconate. This 6 C sugar acid is then decarboxylated by 6-phosphogluconate dehydrogenase into ribulose-5-phosphate.
Therefore, Gis Ribulose-5-phosphate.
(d)
Interpretation:
The CO2generating reaction should be determined.
Concept introduction:
The decarboxylation reactions generate CO2 as a by-product.
Answer to Problem 28P
The reactions F produce CO2.
Explanation of Solution
The six C sugar acid, 6-phosphogluconate formed during pentose phosphate pathway is oxidatively decarboxylated by 6-phosphogluconate dehydrogenase into ribulose-5-phosphate. The final product is a five-carbon sugar, and release CO2.
So. the reaction F produce CO2.
(e)
Interpretation:
6-phosphogluconate should be identified.
Concept introduction:
6-phosphogluconate is a 6C sugar acid which forms during pentose phosphate pathway.
Answer to Problem 28P
The compound E in the reaction is 6-phosphogluconate.
Explanation of Solution
In the first step of the oxidative phase of pentose phosphate pathway, C-1 of glucose-6-phosphate is dehydrogenated into 6-phosphoglucono-⏹-lactone by glucose-6-phosphate dehydrogenase which is hydrolyzed by a lactonase resulting 6-phosphogluconate.
The end product of above reaction is 6-phosphogluconate. Thus the compound E in the reaction is 6-phosphogluconate.
(f)
Interpretation:
The reaction that is catalyzed by phosphopentose isomerase should be determined.
Concept introduction:
Phosphopentose isomerase is an enzyme which involves in isomerization reaction.
Answer to Problem 28P
The reactions H uses Phosphopentose isomerase enzyme.
Explanation of Solution
Ribulose-5-phosphate is isomerized to ribose-5-phosphate by phosphopentose isomerase. The enzyme, phosphopentose isomerase catalyze the conversion of a ketose sugar (Ribulose-5-phosphate ) to an aldose sugar (ribose-5-phosphate).
Therefore, the reaction H needs the enzyme phosphopentose isomerase.
(g)
Interpretation:
Ribose-5-phosphate should be identified.
Concept introduction:
Ribose-5-phosphate is the end product of the oxidative phase of pentose phosphate pathway.
Answer to Problem 28P
The compound I in the reaction is Ribose-5-phosphate.
Explanation of Solution
The ribulose-5-phosphate is obtained in pentose phosphate pathway when the ribose-5-phosphate is isomerized by phosphopentose isomerase.
Therefore, the compound I in the reaction is Ribose-5-phosphate.
(h)
Interpretation:
Reaction catalyzed by lactonase should be determined.
Concept introduction:
Lactonases catalyzes the hydrolysis of ester bonds.
Answer to Problem 28P
The reactions D uses the enzymeLactonases.
Explanation of Solution
The degydrogenated product of glucose-6-phospahte is 6-phosphoglucono-⏹-lactone. This is a 6 membered ring structure and have an ester bond between C-1 carbonyl carbon and C-5 hydroxyl Oxygen. This bond is hydrolyzed by lactonase and to produce 6-phosphogluconate. The reaction is indicated by letter D.
(i)
Interpretation:
Glucose-6-phosphate should be identified.
Concept introduction:
The pentose phosphate pathway is initiated by the oxidation of glucose-6-phosphate.
Answer to Problem 28P
The compound A in the reaction is glucose-6-phosphate.
Explanation of Solution
Glucose-6-phosphate is a 6-carbon sugar and have a ring structure where the hydroxyl group at C-6 is phosphorylated.
The compound A in the reaction is glucose-6-phosphate.
(j)
Interpretation:
The reaction catalyzed by 6-phosphogluconate dehydrogenase should be determined.
Concept introduction:
Dehydrogenases are the enzymes which catalyzes the removal of hydrogen molecules with the help of coenzymes NAD and FAD.
Answer to Problem 28P
The reactions F uses the enzymedehydrogenases.
Explanation of Solution
6-phosphogluconate is oxidatively decarboxylated by 6-phosphogluconate dehydrogenase into ribulose-5-phosphate which is indicated by reaction F.
(k)
Interpretation:
Reaction that is catalyzed by glucose-6-phosphate dehydrogenase should be determined.
Concept introduction:
In the first reaction of pentose phosphate pathway glucose-6-phosphate is dehydrogenated to produce phosphoglucono-⏹-lactone.
Answer to Problem 28P
The reactions B uses the enzymeglucose-6-phosphate dehydrogenases.
Explanation of Solution
In the first step of pentose phosphate pathway, Glucose-6-phosphate is dehydrogenated at C-1 by glucose-6-phosphate dehydrogenase enzyme into 6-phosphoglucono-⏹-lactone.
So, the reactions B uses the enzymeglucose-6-phosphate dehydrogenases.
Want to see more full solutions like this?
Chapter 20 Solutions
BIOCHEMISTRY-ACHIEVE (1 TERM)
- In a diffraction experiment of a native crystal, intensity of reflection (-1 0 6) is equivalent to the intensity of reflection (1 0 -6). true or false?arrow_forwardin an x-ray diffraction experiment, moving the detector farther away from the crystal will allow collection of reflection of reflections with high Miller indices. true or false?arrow_forwardShow the mechanism for the acid-catalyzed formation of an [α-1,6] glycosidic linkagebetween two molecules of α-D-glucopyranose.arrow_forward
- Label the following polysaccharide derivatives as reducing or nonreducing. a. C. b. HO CH₂OH CH2OH OH OH OH OH OH HOCH₂ OH OH OH HOCH₂ HO HO HO OH OH ΙΟ CH₂OH OH OH "OH OHarrow_forwardFor a red blood cell (erythrocyte) undergoing active glycolysis, briefly explain how increases in concentration of the following factors are likely to affect glycolytic flux. a. ATP b. AMP c. F-1,6-BP d. F-2,6-BP e. Citrate f. Glucose-6-phosphatearrow_forwardThe ∆G°’ for hydrolysis of phosphoenol pyruvate is -62.2 kJ/mol. The standard freeenergy of ATP hydrolysis is -30.5 kJ/mol. A. What is the standard free energy and K eq of the spontaneous reaction betweenADP/ATP and phosphoenol pyruvate. B. Repeat A for F-1,6-BP (∆G°’=-16.7 kJ/mol) and 1,3-BPG (∆G°’=-49.6 kJ/mol)hydrolysis. C. If the ATP and ADP concentrations are 8mM and 1mM respectively, what would bethe ratio of pyruvate/phosphoenolpyruvate at equilibrium?arrow_forward
- Answerarrow_forward13. Which one is the major organic product of the following sequence of reactions? A OH (CH3)2CHCH2COOH SOCI2 CH3OH 1. CH3MgBr 2. H₂O, H+ B C D OH E OHarrow_forward14. Which one is the major organic product of the following sequence of reactions? (CH3)2CH-COCI CH3OH 1. DIBALH, -78°C 1. PhCH2MgBr ? 2. H2O, HCI 2. H2O, HCI OH OMe A Ph B Ph OH Ph C OMe Ph D E OH .Pharrow_forward
- 6. Which one is the major organic product obtained from the following reaction? CO₂Me 1. LiAlH4 2. H₂O CH₂OH CH₂OCH3 5555 HO A B HO C HO D CH₂OH E ?arrow_forward1. (10 points) Pulverized coal pellets, which may be ° approximated as carbon spheres of radius r = 1 mm, are burned in a pure oxygen atmosphere at 1450 K and 1 atm. Oxygen is transferred to the particle surface by diffusion, where it is consumed in the reaction C + O₂ →> CO₂. The reaction rate is first order and of the form No2 = k₁C₁₂(r), where k₁ = 0.1 m/s. Neglecting changes in r, determine the steady-state O₂ molar consumption rate in kmol/s. At 1450 K, the binary diffusion coefficient for O2 and CO2 is 1.71 x 10ª m²/s.arrow_forward2. (20 points) Consider combustion of hydrogen gas in a mixture of hydrogen and oxygen adjacent to the metal wall of a combustion chamber. Combustion occurs at constant temperature and pressure according to the chemical reaction 2H₂+ O₂→ 2H₂O. Measurements under steady-state conditions at 10 mm from the wall indicate that the molar concentrations of hydrogen, oxygen, and water vapor are 0.10, 0.10, and 0.20 kmol/m³, respectively. The generation rate of water vapor is 0.96x102 kmol/m³s throughout the region of interest. The binary diffusion coefficient for each of the species (H, O̟, and H₂O) in the remaining species is 0.6 X 10-5 m²/s. (a) Determine an expression for and make a qualitative plot of C as a function of distance from the wall. H2 (b) Determine the value of C2 at the wall. H2 (c) On the same coordinates used in part (a), sketch curves for the concentrations of oxygen and water vapor. This will require you to calculate Co, and C. 02 H20 (d) What is the molar flux of water…arrow_forward
BiochemistryBiochemistryISBN:9781305577206Author:Reginald H. Garrett, Charles M. GrishamPublisher:Cengage Learning
BiochemistryBiochemistryISBN:9781305961135Author:Mary K. Campbell, Shawn O. Farrell, Owen M. McDougalPublisher:Cengage Learning
Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning