Bio Chemistry

BIOCHEMISTRY 3(2+1)

Lesson 8 : Lipids- Introduction, Classification and Functions

Steroids

1. Called isoprenoids because their structure is similar to isoprene.
2. Cholesterol is an important component of cell membranes of animals, but rare in plants and absent in procaryotes.
3. Also have mammalian steroid hormones (estrogen, androgens) and bile salts.
4. Differ in length of side chain at C-17, number and location of methyl groups, double bonds, etc.
5. Cholesterol’s role in membranes is to broaden the phase transition of cell membranes ---> increases membrane fluidity because cholesterol disrupts packing of fatty acyl chains.