Use Zimmerman & Snow p 407.

Respond to classmate discussion board

Part 1.  Use Zimmerman & Snow p 407. What are free radicals? How do they damage cells?

 Atoms consist of protons and neutrons in the nucleus and electrons in the electron cloud surrounding the nucleus. When the electrons are paired, the atom is stable. When the electrons are not paired, the atom becomes unstable and is now considered a free radical. Free radicals can cause damage to cells by stealing electrons from other atoms in an attempt to pair their own electrons. The result is a new free radical that attempts to steal electrons, creating a chain reaction in cells that causes damage over time. This chain reaction will continue until a defense mechanism is encountered.

 Free radical detoxifying enzymes: Use Zimmerman & Snow pp 408-409. Identify three free radical detoxifying enzymes and describe the function of each of them.

 One defense mechanism in the body is free radical detoxifying enzymes. These enzymes help protect cells in the body from damage caused by free radicals. The three free radical detoxifying enzymes are Superoxide Dismutases (SOD), Catalase, and Glutathione Peroxidases.

 SOD enzymes usually have a cofactor of manganese, copper, or zinc. With these cofactors, SOD converts free radicals like superoxides into hydrogen peroxide and oxygen. Breaking down free radicals into other elements makes them less reactive, which reduces the damage to the cells in the body. Catalase works with the cofactor iron to further break down the hydrogen peroxide leftover from the SOD enzymes. Glutathione Peroxidases work with the cofactor selenium to break down hydrogen peroxide into water and oxygen.

References:

Zimmerman, M., & Snow, B. (2012). An Introduction to Nutrition 1.0