Question

When cross sectional area of the head group and acyl side chain is similar, which of the following lipid aggregates formation is favored?

Seleccione una:

a. Liposome

b. Micelles

c. Bilayer

d. Myelin sheath

e. Any of these may be formed, it depends on the acyl side chain polarity

Answer 1

c. Bilayer

Cellular membranes are composed of phospholipids and sphingolipids Bilayer formation is favored in glycerophospholipids and sphingolipids, where the cross-sectional area of the head group and the acyl side chain are similar. Glycerophospholipids are made by combining glycerol, two fatty acids, one phosphate group, and one functional group .Glycerophospholipids are synthesised from dihydroxy acetone phosphate.  Glycerophospholipids are the most abundant phospholipids,which are found in highest amounts in the membranes of all cells. Sphingolipids are similar to glycerophospholipids, contain the fatty acid sphingosine and contain a phosphate group attached to both sphingosine and a functionl group.They are all derivatives of ceramides. Complex sphingolipids are located in the plasma membrane of animal cells mainly in nerve cells with a function to protect the cell surface from harmful environmental factors.They also act as antigenic determinants of the cell membrane. Sphingolipids are the second large class of membrane lipids. Glycerophospholipids and sphingolipids spontaneously self-associate in water to form bilayer vesicles.