The first region on either side of the bilayer is the hydrophilic headgroup. This portion of the membrane is completely hydrated and is typically around 8-9Å thick. In phospholipid bilayers the phosphate group is located within this hydrated region, approximately 5Å outside the hydrophobic core.[1] In some cases, the hydrated region can extend much further, for instance in lipids with a large protein or long sugar chain grafted to the head. One common example of such a modification in nature is the lipopolysaccharide coat on a bacterial outer membrane,[2] which helps retain a water layer around the bacterium to prevent dehydration.
- ^ Nagle, JF; Tristram-Nagle, S (November 2000). "Structure of lipid bilayers". Biochim. Biophys. Acta. 1469 (3): 159–95. doi:10.1016/s0304-4157(00)00016-2. PMC 2747654. PMID 11063882.
{{cite journal}}: CS1 maint: date and year (link) - ^ Parker J, Madigan MT, Brock TD, Martinko JM (2003). Brock biology of microorganisms. Upper Saddle River, NJ: Prentice Hall.
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