The Embden-Meyerhof or glycolytic pathway is undoubtedly
the most common pathway for glucose degradation to pyruvate in
stage two of catabolism. It is found in all major groups of microorganisms
and functions in the presence or absence of O2.
Glycolysis [Greek glyco, sweet, and lysis, a loosening] is located
in the cytoplasmic matrix of procaryotes and eucaryotes.
The pathway as a whole may be divided into two parts.
In the initial six-carbon stage, glucose
is phosphorylated twice and eventually converted to fructose 1,6-
bisphosphate. Other sugars are often fed into the pathway by conversion
to glucose 6-phosphate or fructose 6-phosphate. This preliminary
stage does not yield energy; in fact, two ATP molecules
are expended for each glucose. These initial steps “prime the
pump” by adding phosphates to each end of the sugar. The phosphates
will soon be used to make ATP.
The three-carbon stage of glycolysis begins when the enzyme
fructose 1,6-bisphosphate aldo…