Lipids are important components of cell membranes and include triacylglycerols, olestra, cholesterol, and steroids. Cell membranes have a fluid mosaic structure and are asymmetric, with different compositions on each side of the bilayer. Membranes undergo phase transitions and can fuse together over time.

2. Lipids and Membranes

3. TRIACYLGLYC
EROL
(TAG)

4. OLESTR
A
TAG

5. Head
Tail

11. CHOLESTE
ROL

12. STEROID
S

13. MANY STEROIDS ARE DERIVED
FROM CHOLESTEROL

14. THE FLUID MOSAIC MODEL

15. Fusion
After 40 minutes

17. MEMBRANES ARE
ASYMMETRIC

18. Membrane Phase Transitions

19. PHASE
TRANSITIO
NS