Question

How antioxidants in egg yolk are vital in preventing damage to developing bird embryos from free radicals ? Please explain in detail and type out answer. Thank you very much.

Answer 1

The yolk of embryo acts like antioxidant beacuse as follows

1. The egg of birds contains nutrients which are essential for the development of embryo.

2, Apart from nutrients it also contain antioxidants. There are three types of antioxidants. They are

a. Fat soluble antioxidants includes VitaminA, E, ubiquinones and carotenoids etc.

b. Water-soluble antioxidants includes uric acid, taurin and ascorbic acid etc.

c. Antioxidant enzymes includes catalase, superoxide dismutase, glutathione peroxidase etc.

3. Free radicals are atoms or molecules contain unpaired electrons. These free radicals derive from oxygen and nitrogen and are unstable, very reactive damage biological molecules such as DNA, proteins, lipids and carbohydrates.

4. Superoxide radical is the main first level of free radical produced in the cells during embryo development. The enzyme superoxide dismutase, dismutates the superoxide to form hydrogen perxides. This hydrogen peroxide detoxified by GSH-Px or catalase which can reduce it into water.

5. The second level of defence consists of chain-breaking antioxidants such as ligases, polymerases, transferases, phospholipases etc.

6. The second level antioxidants inhibit peroxidation by keeping the chain length as small as possible so that they can prevent propagation of lipid peroxidation by removing peroxyl radical intermediates.

7. Third level of defense includes eliminating damaged molecules or reparing them. The third level antioxidants are lipases, nucleases, proteases or peptidases, polymerases, phospholipases.

8. All these antioxidants associated with each other to form integrated antioxidant system. This is very essential for maximum protection from toxic products of thier metabolism.