Lipids and Biomembranes

ID #2193

How/why does the lengthening of fatty acid tails increase the stability of a lipid membrane? Also, if steroids are amphipathic, then how are they able to stay inside of the hydrophobic region?

Longer fatty acid tails provide more hydrocarbon atoms for adjacent tails to interact with hydrophobically. More interaction sites from more hydrocarbons = more membrane stability.

Look at the chemical structure of the steroid cholesterol in one of the slides from lecture 8. As you can see, the region marked hydrophilic is just a hydroxyl (OH) group. The majority of the molecule is hydrophobic, so the four rings and small hydrocarbon tail all very happily are buried in the hydrophobic lipid-rich space of the membrane. It is still considered amphipathic though because it has both hydrophilic and hydrophobic regions.

Print this record Print this record
Send to a friend Send to a friend
Show this as PDF file Show this as PDF file
Export as XML-File Export as XML-File