3. The dioxygenase pathway of oxidation . Differences from the monooxidase pathway . Examples of reactions . Cofactors and coenzymes of the process. Antioxidant:5. Mechanisms of antioxidan t defence (AOP) their classification. Pro-oxidants of peroxidation of phospholipids of cell membranes,proteins and nucleic acids .Formation of malonic dialdehyde and diene conjugates.

The dioxygenase pathway of oxidation involves the incorporation of molecular oxygen (O2) into the substrate, resulting in the formation of two oxygen-containing products. This pathway is different from the monooxidase pathway, which involves the removal of one oxygen atom from the substrate, forming a single oxygen-containing product.<br /><br />Examples of reactions in the dioxygenase pathway include the conversion of amino acids to alpha-keto acids, the conversion of fatty acids to hydroxy fatty acids, and the conversion of aromatic compounds to dihydroxy compounds.<br /><br />The cofactors and coenzymes involved in the dioxygenase pathway include NADH, NADPH, and molecular oxygen (O2). These molecules play a crucial role in the oxidation reactions that occur in this pathway.<br /><br />Antioxidants are molecules that can prevent or slow down the oxidation of other molecules. They can neutralize free radicals and reactive oxygen species, preventing cellular damage. There are several mechanisms of antioxidant defense, including the scavenging of free radicals, the chelation of metal ions, and the inhibition of oxidative enzymes. Antioxidants can be classified into different categories based on their mechanism of action, such as chain-breaking antioxidants, metal-chelating antioxidants, and enzyme inhibitors.<br /><br />Pro-oxidants are molecules that can promote oxidation reactions. They can initiate the formation of free radicals and reactive oxygen species, leading to cellular damage. One example of a pro-oxidant is hydrogen peroxide (H2O2), which can be converted into reactive oxygen species that can damage cellular components. The peroxidation of phospholipids, proteins, and nucleic acids can lead to the formation of malonic dialdehyde and diene conjugates, which are markers of oxidative stress and can contribute to cellular damage and aging.