Which of the following statements about biological membranes
     Which of the following statements about biological membranes is not true?  They contain carbohydrates that are covalently bound to proteins and lipids  They are very large, sheetlike structures with closed boundaries  They are symmetric because of the symmetric nature of lipid bilayers  They can be regarded as two-dimensional solutions of oriented proteins and lipids  They contain specific proteins that medicate their distinctive functions 
  
  Solution
Answer: (C) They are symmetric because of the symmetric nature of lipid bilayers.
The above statement is not true.
Lipid bilayer membranes are asymmetric, which means the outside face of membrane is always different from the inner face of the membrane.

