VITAMINS AND STEROIDS Flashcards
examples of fat soluble vitamins?
vit A, vit D, vit E, vit K
examples of water soluble vitamins?
- B complex vitamins, vitamin C
what are provitamins?
- precursors to vitamins
what are vitamers?
- vitamin isomers
are all vitamers isoprenoids in vit A?
yes
examples of vitamers in vit A?
retinoic acid, retinaldehyde (retinal), retinol, retinyl esters
examples of provitamins in vitamin A?
β-carotene, α-carotene, γ-carotene
what is retinaldehyde?
- used iin the eye to form rhodopsin
what is retinyl palmitate?
- ester of palmitic acid and retinol
- main form of diet - converted to retinol in SI.
- retinol = storage form
what is retonoic acid?
- synthesised from retinol in male gonads
what is xeropthalmia
- thickening of surface layers of the eye
what is keratomalacia
inability to synthesise specialist tissues of eye surface
what is nyctalopia?
- lack of retinaldehyde
- night blindness
what is photophobia?
- aversion to bright light due to lack of light absorbing rhodopsin in retina
what issues does hypovitaminosis A cause?
- xerophthalmia
- keratomalcia
- nyctalopia
- photophobia
- weight loss
vitamers of vitamin d?
- ergocalciferol (D2), cholecalciferol (D3),
22-dihydroergocalciferol (D4), sitocalciferol (D5).
symptoms of hypovitaminosis D?
- rickets
- osteoporosis
- clinical depression
schizophrenia - muscular pain
- muscle twitching
properties of vitamin E?
- eight vitamers = 4 are tocopherols, 4 are
tocotrienols. - potent antioxidants = heads can donate electrons and hydrogens to oxidising agents. PROTECTS CELL MEMBRANE
symptoms of hypovitaminosis E?
neurological damage
vitamers of vitamin K?
- phylloquinone (K 1) and menaquinone (K 2)
symptoms of hypovitaminosis of vitamin K?
- issues with blood clotting
vitamers of vitamin c?
L - ascorbic acid
- dehydroascorbic acid
why is vit c known as a potent antioxidant?
what are steroids?
- organic compounds with 4 joint rings arranged in specific way
