1 Aden, Yemen is at 12 49'N, 45 1'E, 3 m (10 ft). 2  See map. 3  Aden has a subtropical desert / low-latitude arid hot climate (K ppen-Geiger classification: BWh). 4  The annual average temperature is 29.2 degrees Celsius (84.5 degrees Fahrenheit).
The core of a sphingolipid is an amino alcohol called sphingosine. Complex sphingolipids located in the plasma membrane of animal cells (especially nerve cells) have a structural function and are believed to protect the cell surface from harmful environmental factors.
Phospholipids are a class of lipids that are a major component of all cell membranes. They can form lipid bilayers because of their amphiphilic characteristic. The structure of the phospholipid molecule generally consists of two hydrophobic fatty acid tails and a hydrophilic head consisting of a phosphate group.n biological systems, the phospholipids often occur with other molecules (e.g., proteins, glycolipids, sterols) in a bilayer such as a cell membrane. Lipid bilayers occur when hydrophobic tails line up against one another, forming a membrane of hydrophilic heads on both sides facing the water.