Glycolysis involves the conversion of glucose to pyruvate, with the formation of ATP. It occurs in the cytosol.
a. The goal of the early portion of the pathway is formation of 3-carbon sugar phosphates.
b. Energy extraction involves oxidation, isomerization, dehydration, and two phosphate transfer reactions.

Notice the reactions that repeat(the capital letters refer to the position of the reaction in the pathway

Kinases:
A. Hexokinase: An enzyme that transfers phosphate from ATP to acceptor molecule is called a kinase.
Mg^{2+-ATP is the form of ATP recognized by these enzymes, because all of their binding sites for ATP
evolved in the presence of the magnesium-ATP complex.
C. Phosphofructokinase
G. Phosphoglycerate kinase (named for reverse reaction)
J. Pyruvate kinase (named for reverse reaction)}

Isomerases:
B. Phosphoglucoisomerase: A reaction that involves shifting the carbonyl carbon from C-1 to C-2.
E. Triose phosphate isomerase

Individual reactions: D. Aldolase:
F. Glyceraldehyde 3-phosphate dehydrogenase: In this reaction an aldehyde group is converted to an acid (with the simultaneous formation of an acid anhydride)
H. Phosphoglyceromutase
I. Enolase (removal of water)

Summary:
Glucose + 2 P_i + 2 ADP + 2 NAD⁺ --> 2 pyruvate + 2 ATP + 2 NADH + 2 H⁺ + 2 HO

Invested = 2 ATPs; Recovered = 4 ATPs; Net = 2