(1) Glycolysis represents phase I of respiration.
(2) This pathway is common to both aerobic
and anaerobic respiration.
(3) These reactions are completed in the cell
cytoplasm (cytosol). Therefore, glycolysis is also called cytoplasmic
(4) Glycolysis involves a series of reactions
in which a molecule of 6-C glucose is broken down in a step-wise
manner into two molecules of 3-C pyruvic acid.
(5) Each step (reaction) is controlled by a
specific enzyme and is reversible.
(6) Reactions in the glycolysis are anaerobic
in nature,( i.e. they do not require molecular oxygen).
6-C Glucose is the most commonly used organic substrate
for respiratory breakdown because
(i) It is most readily available.
(ii) It is soluble and can be easily transported
Reactions of glycolysis (EMP pathway) involve :
(A) Phosphorylation of glucose (preparatory
phase), isomerization to fructose-6-phosphate, and phosphorylation
to fructose-I, 6-biphosphate.
(B) Cleavage of Fructose 1, 6 diphosphate to
2 3-C PGAL.
(C) Formation of 3-C pyruvic acid (end product
of glycolysis). Various steps (intermediate reactions) in
glycolysis are as follows.