
Concept explainers
One of the steps in the pentose phosphate pathway for glucose catabolism is the reaction of xylulose 5-phosphate with ribose 5-phosphate in the presence of a transketolase to give glyceraldehyde 3-phosphate and sedoheptulose 7-phosphate.
(a) The first part of the reaction is nucleophilic addition of thiamin diphosphate (TPP) ylide to xylulose 5-phosphate, followed by a retro-aldol cleavage to give glyceraldehyde 3-phosphate and a TPPcontaining enamine. Show the structure of the enamine and the mechanism by which it is formed.
(b) The second part of the reaction is addition of the enamine to ribose 5-phosphate followed by loss of TPP ylide to give sedoheptulose 7-phosphate. Show the mechanism.

Trending nowThis is a popular solution!

Chapter 29 Solutions
Student Value Bundle: Organic Chemistry, + OWLv2 with Student Solutions Manual eBook, 4 terms (24 months) Printed Access Card (NEW!!)
Additional Science Textbook Solutions
College Physics: A Strategic Approach (3rd Edition)
Physical Science
Organic Chemistry
Applications and Investigations in Earth Science (9th Edition)
- If the energy absorbed per mole of photons is 450 kJ, the number of Einsteins absorbed per 1 mole.arrow_forwardWhen propionic aldehyde in vapor form at 200 mmHg and 30°C is irradiated with radiation of wavelength 302 nm, the quantum yield with respect to the formation of CO is 0.54. If the intensity of the incident radiation is 1.5x10-3 W, find the rate of formation of CO.arrow_forwardDraw mechanismarrow_forward
- Does Avogadro's number have units?arrow_forwardExplain why the total E in an Einstein depends on the frequency or wavelength of the light.arrow_forwardIf the dissociation energy of one mole of O2 is 5.17 eV, determine the wavelength that must be used to dissociate it with electromagnetic radiation. Indicate how many Einstein's of this radiation are needed to dissociate 1 liter of O2 at 25°C and 1 atm of pressure.Data: 1 eV = 96485 kJ mol-1; R = 0.082 atm L K-1; c = 2.998x108 m s-1; h = 6.626x10-34 J s; NA = 6.022x 1023 mol-1arrow_forward
- Indicate the number of Einsteins that are equivalent to 550 kJ mol⁻¹ of absorbed energy (wavelength 475 nm).arrow_forwardIndicate the number of einsteins that are equivalent to 550 kJ mol⁻¹ of absorbed energy?arrow_forwardA unit used in photochemistry is the einstein. If 400 kJ mol-1 of energy has been absorbed, how many einsteins is this equivalent to?arrow_forward
- For the condensation reaction between Alanine and histidine write the amididation reaction mechanism using arrows then write the three letter code for the product of the reaction and the one letter code for the product of the reaction.arrow_forwardWrite the amididation reaction mechanism of p-aminophenol and acetic acid to produce acetaminophen please use arrows.arrow_forwardName the following using IUPAC.arrow_forward
