Glycolysis, part of cellular respiration, is a sequence of reactions that constitute the first phase of most carbohydrate catabolism (catabolism meaning the breaking down of larger molecules into smaller ones). Glycolysis occurs in most organisms in the cytosol of the cell. In glycolysis glucose, which is a form of sugar is eventually converted to pyruvate. The pyruvate end product of glycolysis can be used in either anaerobic respiration if no oxygen is available or in aerobic respiration via the TCA cycle which yields much more usable energy for the cell.
— Electron Transport Chain (ETC) – Oxidative Phosphorylation: https://goo.gl/05oOpi