BIOLOGY 1A03 Lecture Notes - Lecture 1: Lipid Raft, Phospholipid, Amphiphile

• School: McMaster University
• Department: Biology
• Course: BIOLOGY 1A03
• Professor: Rosa Da Silva

Document Summary

Cell membranes are made phospholipids (hydrophobic tails and hydrophilic heads) Tails are hydrophobic due to their long carbon-carbon chains. Longer carbon chains reduce uidity and make the membrane less permeable. Factors affecting membrane uidity: unsaturated vs saturated fatty acids. Saturated is tighter packed and uidity is decreased. Lipid rafts allow for cells to communicate and or crawl. >to aggregate a lipid raft, the membrane must be made left uid. 2. number of carbons in the fatty acid tail. Lipid rafts have longer tails and usually sit up higher on the membrane: temperature. More uidity at higher temperatures due to more vibrations within the membrane: the presence or absence of cholesterol. At lower temperatures, cholesterol allows the membrane to remain uid. In warm temperatures, cholesterol decreases uidity as it can then interact with phospholipid tails (hydrophobic interactions, stack between the phospholipid tails)