BIOLOGY 1A03 Lecture Notes - Lipid Bilayer, Isoprene, Carboxylic Acid

• School: McMaster University
• Department: Biology
• Course: BIOLOGY 1A03
• Professor: Lovaye Kajiura

Document Summary

Cell membrane encloses the cell it is a layer of molecules surrounding the cell, separating it from the external environment. Chemical reactions necessary for life to occur more efficiently b/c reactants collide more. Selective barrier forms keeping molecules that could cause damage out. The most abundant molecule in the cell membrane is the oily and fatty compound lipids. Two types have been produced in spark-discharge origin of life experiments, indicating existence in prebiotic soup. When shaken, they enclose around water spontaneously forming compartments of water: this could explain how they enclosed around first self-replicating molecule. Carbon containing compounds; largely nonpolar (hydrophobic) because c-h bonds are nonpolar. Lipid building blocks: isoprene five carbon compound; links end to end to form a hydrocarbon chain: fatty acid carboxyl group head and hydrocarbon chain. Lipids are defined by the physical property of solubility; their structures vary widely. Three most important lipids in cells: fats, steroids, phospholipids.