Sample Biology Paper on fluidity of the cell membrane

Biological membranes are semipermeable membrane within the cell-protecting the
cytoplasm and nucleoplasm from external contact. Most of the membranes have a phospholipid
bilayer, which allows for the organelle's functioning and the exchange of substances between the
organelle and the external environment (Tortora, 1987). The fluid is formed through transport
activities within the cell. The exchange of substances within the cell through diffusion results in
the fluidity of the cell. The phospholipid bilayer structure maintains the fluidity of the cell. The
fluidity is affected by the surrounding temperature and the length of fatty chains. The fluidity of
the membrane is determined by the cells' arrangement, with fluidity increasing in loosely
arranged cells (Tortora, 1987).
There are two separate cells for the case provided, one having long lipids with nonpolar
tails and no double bond. The other section has both long and short nonpolar lipids, with some of
the long tails having double bonds. The membrane's nonpolar characteristic is due to the
replacement of a fatty acid group in the membrane. Typically, phospholipids are characterized by
a non-covalent bond. For the membrane provided, the second membrane has double bonds
allowing for easy movement of the fluid within the cell. Therefore, the second membrane is
referred to as Jess fluid since it contains both short and long nonpolar tails with a double
covalent bond.




Tortora, G. (1987). Principles of Anatomy and Physiology. New York: Harper and Row.