How is hydrogen peroxide produced in cells?
Hydrogen peroxide (H2O2) can be produced in cells through several pathways including:
1. Enzymatic reactions: Enzymes such as oxidases, peroxidases and catalases catalyze the production of H2O2 from molecular oxygen (O2) and water (H2O).
2. Mitochondrial respiration: During the process of oxidative phosphorylation, reactive oxygen species (ROS) are generated as byproducts, including H2O2.
3. Nitric oxide (NO) metabolism: Nitric oxide synthase (NOS) catalyzes the synthesis of NO, which can react with ROS to form H2O2.
4. Inflammation: Inflammation triggers the production of ROS, and H2O2 is one of the oxidants generated.
Overall, the production of H2O2 in cells occurs through multiple pathways and is tightly regulated to prevent harmful levels of oxidative stress.