Biology 1002B Lecture 13: lecture 5

• School: Western University
• Department: Biology
• Course: Biology 1002B
• Professor: Beth Mac Dougall- Shackleton

Document Summary

Readings: what are the fundamental aspects of the fluid mosaic model. The lipid molecules of all biological membranes exist in a double layer called a bilayer. Proteins move more slowly in the fluid environment of the membrane because they are larger than lipid molecules. The term lipid refers to a diverse group of water- insoluble molecules that include fats, phospholipids (dominant in membranes), and steroids. Lipids are non- polar biological molecules composed mostly of hydrogen and carbon (hydrocarbons) Since they are nonpolar, lipids dissolve much more rapidly in nonpolar solvents (acetone, chloroform) Lipids are not large enough to be considered true macromolecules and they are not considered polymers of defined monomeric subunits. The structural backbones of all lipids is derived form one of two hydrocarbon molecules: isoprene and fatty acid. Isoprenes are 5 carbon molecules that when linked together can form long hydrocarbon chains (structural unit in steroids, phospholipids)