There are three parts to cell respiration, each of which take place in different areas of the cell. The first stage, glycolysis, takes place in the cytosol (the liquid part of the cytoplasm). Glycolysis breaks glucose molecules down into smaller ones of pyruvate. Then the pyruvate moves into the matrix of the mitochondrion, where the Krebs cycle takes place. This creates chemical energy. The energy is released in the third part of respiration, which takes place along the inner membranes of the mitochodria.