2.  Vitamin A is known as retinol and occurs only in animal products.  Plants have a yellowish dye known as beta-Carotene (provitamin) which in animal cells can be easily split into two molecules of vitamin A.

3. RETINOL C 20 H 29 OH BETA-CAROTENE C 40 H 56

4.  soluble in fat  relatively stable  sensitive to the light  sensitive to oxygen (administered with vitamin E which is antioxidant)

5.  play an important role in vision, bone growth, reproduction, cell differentiation and cell division.  helps regulate the immune system which helps prevent or fight off infections by making white blood cells that destroy harmful bacteria and viruses.  help lymphocytes fight infections more effectively.

6. Better absorption of vitamin A will give us: -the presence of fat -vitamin D -complex vitamins of the B group -vitamin C -vitamin E -calcium -zinc -phosphorus Worse absorption of vitamin A: -sodium benzoate, -vitamin D - deficiency, -caffeine, -nicotine, -alcohol, -nitrites, -steroids -laxatives, -damaged pancreas.

7.  Medicine In the treatment of: -acne -Stretch marks -dyskeratosis -psoriasis -photoaging of the skin -lack of vitamin A  In cosmetiscs -creams -lotions These cosmetiscs are very helpful for people with skin problems.

8.  egg  butter  cod-liver oil  cheese  whole milk  fish  meat  spinach  grapes  carrote  yellow pumpkin  tomatos  avocado

9.  liver abnormality (symptoms of poisoning)  central nervous system disorders  birth defects  reduced bone mineral density that may result in osteoporosis

10.  skin changes  respiratory infections  anemia and apathy  increased intracranial pressure  night blindness  damaged cornea of eye  inhibition of growth

11.  http://www.witaminaa.com.pl/wchlanianie- witamina-a/ http://www.witaminaa.com.pl/wchlanianie- witamina-a/  http://portal.abczdrowie.pl/naturalne- wystepowanie-witamin http://portal.abczdrowie.pl/naturalne- wystepowanie-witamin  http://www.biotechnologia.uni.opole.pl/bibliote ka/docs/WITAMINY-PRAWDA-I-MITY.pdf http://www.biotechnologia.uni.opole.pl/bibliote ka/docs/WITAMINY-PRAWDA-I-MITY.pdf  http://forumsportowe.us/viewtopic.php?t=179 http://forumsportowe.us/viewtopic.php?t=179  http://www.nhs.uk/Conditions/vitamins- minerals/Pages/Vitamin-A.aspx http://www.nhs.uk/Conditions/vitamins- minerals/Pages/Vitamin-A.aspx  http://jejzdrowie.pl/dzialanie-witaminy-a http://jejzdrowie.pl/dzialanie-witaminy-a  Claude A.Villee- „Biologia”  Phil Bradfield and Steve Potter -LONGMAN GCSE Biology

12.  Weronika Kielar  Karolina Grzeszek  Magdalena Adamowicz  Karolina Kurys THANK YOU FOR YOUR ATTENTION