Endotrophic. (Or mycorrhizas), with the mycelium of the fungus within cells of root cortex, e.g.in orchids.

End plate potential. It is the localised depolarization or potential change across the membrane in the motor end plate region of a muscle fibre at a neuro muscular junction.

Entomology. It deals with the study of insects.

Enzyme.
A protein that acts as a catalyst in biochemical reactions. Each enzyme is specific to a particular reaction or group or similar reactions. Many require the association of certain nonprotein cofactors in order to function.

The molecule undergoing reaction (the substrate) binds to a specific active site on the enzyme molecule to form a short lived intermediate; this greatly increases (by a factor of up to 1020) the rate at which the reaction proceeds to form the product. Enzyme activity is influenced by substrate concentration and by temperature and ph, which must lie within a certain range. Other molecule may compete for the active site, causing inhibition of the enzyme or even irreversible destruction of its catalytic properties.

Energy. It is the capacity to do work.

Eosinophilia. An increase in the number of white blood cells from their normal value.

Eosinophil Leucocyte. Polymorphonuclear leucocyte  of vertebrates, containing granules staining in acid dyes such as eosin. In human beings normally about 2-5 per cent of all leucocytes, but become much increased in certain parasitic infections and in allergies.

Ephemeral. A plant that has a very short life cycle. It has many a generation in year.

Epididymis.
Long convoluted tube attached to testis of amniote vertebrates. Receives into one end sperm from testis tubules, which it stores and ripens. Other end leads into was deferents and so to exterior. Embryonically derived from mesonephors and its duct.