NFS382H1 Lecture Notes - Lecture 9: Lipid Bilayer, Conversion Of Units, Cryptoxanthin
14 Apr 2016
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Document Summary
B-ionone ring and a polyunsaturated side- chain with an: alcohol=retinol, aldehyde=reintal, carboxylic group=retinoic acid, ester=retinyl ester. Side chains comprised of 4 isoprenoid units with a series of conjugated double bonds. Double bonds may be in a trans or cis configuration: configuration is very important. Of 600 or so carotinoids only ~10% of vitamin a is activity. Exist as an expanded carbon chain with conjugated double bonds usually but not always with b0ionone ring at one or both ends of the chain. Foods of animal origin-liver, dairy, eggs, fish ,oils, tuna, sardines, herring. Main form in food is retinyl ester such as retinyl palmitate. Some foods may be fortified (eg skim milk/partially skimmed milk) Carotenoids-brightly colour yellow, orange and red fruits and vegetables. Beta carotene-most abundant and contain greatest provitamin a activity. Men +14 900 ug rae (based on liver stores) Women +14 700 ug rae (based on liver stores)
