Scheme 3 shows examples for tetraterpenes having eight isoprene units which are responsible for colours of tomatoes and carrots.

Scheme 3

10.8 Vitamins

• Vitamins A, D, E and F are lipids (Scheme 4). Cleaving of β-carotene generates two molecules of vitamin A that plays important role in vision. Vitamin A is also called as retinol.

Scheme 4