What is glycolysis?
the first step in energy metabolism - the process of splitting glucose (sugar) into 2 molecules of pyruvate and in the process harvesting energy in the form of 2ATP and 2NADH.
Glycolysis is a process that occurs in the cytoplasm of cells - it is common in all kingdoms (Plant, Animal, Fungi, Bacteria, Protist, Archaebacteria & Eubacteria).
Glycolysis does not require oxygen and only harvests 2 molecules of ATP (the universal energy carrier/currency of cells).
If oxygen is available, the breakdown of pyruvate into CO2 and further extraction of ATP yields 36-38 ATP.
If Oxygen is not available, the cell will reinvest the energy in the NADH molecules into pyruvate thorugh a process called fermentation. This reinvestment regenerates the NAD+ precursor to NADH so that another round of glycolysis can occur.