HO.g) Is vitamin A polar or non-polar? Is it likely to be water soluble? Explain.In a study of the effect of B-carotene on Vitamin A levels, it was found that a diet of 15.1 mg of B-carotene resulted in a blood-plasma level of 43 nmol L-1 of Vitamin A.h) Assuming that 100% of the B-carotene is converted to Vitamin A (286 g mol-1), and thatabsorption of B-carotene occurs predominately in the small intestine in an aqueous volumeof 600 mL, estimate the equilibrium constant for the reaction below: (remember the ratio is2 molecules of Vitamin A converted by enzymes from 1 molecule of B-carotene)Vitamin A (intestine) =Vitamin A (plasma) AbsorbanceB-Carotene belongs to a class of compounds called carotenoids. It is the most common form ofcarotene in plants, and is responsible for the red-orange colour seen in autumn leaves. It is alsoresponsible for the colour in vegetables such as carrots, tomatoes, and sweet potato, and is animportant dietary requirement for the production of Vitamin A. The structure of B-Carotene (537 gmol-1) is shown below:a) How many sp2 hybridised carbon atoms are there in a B-Carotene molecule? How manyconjugated double bonds are there? How many chiral carbon atoms does B-Carotene have?b) Is the B-Carotene molecule flexible i.e.can twist and fold on itself or not? Provide anexplanation for your response.c) Is the molecule likely to be water soluble, why/why not?d) B-Carotene is a deep orange-red colour, why?The absorption spectrum for B-Carotene is shown below:200300400500600Wavelength (nm)e) Use the spectrum above to estimate the wavelength where maximum absorption occurs.Calculate the energy of photons absorbed at this wavelength.f) The amount of B-carotene found in a sample of autumn leaves was 24.6 mg B-carotene in100 g of dry weight leaves. Express this concentration as %w/w.Plant carotenoids are the primary dietary source of vitamin A worldwide, with B-carotene as thebest-known provitamin A carotenoid. One molecule of B-carotene can be cleaved by intestinalenzymes into two molecules of Vitamin A. The structure of Vitamin A is shown below:HO,

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B-Carotene belongs to a class of compounds called carotenoids. It is the most common form of carotene in plants, and is responsible for the red-orange colour seen in autumn leaves. It is also responsible for the colour in vegetables such as carrots, tomatoes, and sweet potato, and is an important dietary requirement for the production of Vitamin A. The structure of B-Carotene (537 g mol-1) is shown below: a) How many sp? hybridised carbon atoms are there in a B-Carotene molecule? How many conjugated double bonds are there? How many chiral carbon atoms does B-Carotene have? b) Is the B-Carotene molecule flexible i.e. can twist and fold on itself or not? Provide an explanation for your response.

B-Carotene belongs to a class of compounds called carotenoids. It is the most common form of carotene in plants, and is responsible for the red-orange colour seen in autumn leaves. It is also responsible for the colour in vegetables such as carrots, tomatoes, and sweet potato, and is an important dietary requirement for the production of Vitamin A. The structure of B-Carotene (537 g mol-1) is shown below: a) How many sp? hybridised carbon atoms are there in a B-Carotene molecule? How many conjugated double bonds are there? How many chiral carbon atoms does B-Carotene have? b) Is the B-Carotene molecule flexible i.e. can twist and fold on itself or not? Provide an explanation for your response.

Organic Chemistry

8th Edition

ISBN:9781305580350

Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Publisher:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Chapter5: Alkenes: Bonding, Nomenclature, And Properties

Section: Chapter Questions

Problem 5.31P

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