GLOSSARY

Triose Phosphate Isomerase (TPI) interconverts the pathway's two triose phosphates.

For example, after training changes an enzyme result, first ask whether it was measured in blood, tissue or purified protein. Then assess assay conditions, nutrition and time since the last session alongside actual performance; this comparison helps distinguish a regulatory response from a nutritional deficiency or a presumed supplement need.

Cytosolic glycolysis generates pyruvate, reduced carriers and net ATP from glucose or suitable input. It does not directly require oxygen and also runs during aerobic activity. Pyruvate-to-lactate conversion helps regenerate oxidized carrier for continuation. Lactate therefore does not prove absent oxygen, and glycolysis is not only an emergency oxygen-shortage system. The fate of its products depends on demand, compartment and downstream capacity rather than the pathway name alone.

Phosphorylated intermediates retain glucose-derived carbon within cellular networks and support cleavage and group-transfer steps. Glucose phosphate can branch toward glycolysis, glycogen or the pentose pathway; some trioses also link glycerol synthesis. An intermediate's name identifies chemistry, not a guarantee that a higher level means greater flux. Its presence does not create a direct supplement recommendation, and local accumulation may reflect supply, consumption or a downstream constraint.