Abstract
Studies of the pH decreases that accompany the formation of Compound I from ox liver catalase and peroxoacetic acid in unbuffered systems imply that 1 mol of acetic acid is released/mol of catalase ferrihaem Compound I formed. This result is consistent with results previously obtained (Schonbaum & Lo, 1972) for the formation of peroxidase Compound I by using peroxo acid substrate.