Molecular medicine-Physiology of the Adipocyte

Physiology of the Adipocyte
Perhaps the most well-established function
of adipose tissue in man is as a
reservoir for the storage and mobilization
of energy. Cells of the body utilize energy
continuously, yet fuel is obtained from
external sources intermittently. Thus, animals
have a need to be able to efficiently
store energy when food is available and access
that energy during periods of fasting.
Adipose tissue is highly specialized for
the storage of lipid energy in the form of
triglycerides and the mobilization of that
energy in the form of free fatty acids. Of
the energy substrates utilized by tissues,
lipid is most efficiently stored and provides
greater than twice the energy per
gram than either carbohydrate (glycogen)
or protein. The significance of this energy
reserve is readily appreciated when considering
that a man of normal body weight
(70 kg, 10% body fat) can survive 40 days
on energy reserves stored in adipose tissue.