Glycolysis

• Glycolysis occurs in the cytosol just outside the mitochondrion
• This phase requires no oxygen and is therefore an anaerobic phase
• Glucose (consists of 6 carbon atoms) is broken down step by step. Two molecules of pyruvic acid, with 3 carbon atoms each, are formed
• Energy rich H-atoms as well as a small amount of energy, is released and stored in ATP
• Coenzymes (hydrogen carriers) carry the energy rich hydrogen atoms to the third phase (oxidative phosphorylation)