Lecture 25 Flashcards
What is a free radicle?
a highly reactive unpaired electron in the outer orbit
What are free radicles so dangerous?
They have a very short half life (nanoseconds) and can generate other free radicals in a chain reaction causing extensive damage.
What is an examples of a reactive oxygen species?
hydrogen peroxide
What is an example of a reactive nitrogen species?
nitric oxide
What is an example of a chemical that is a free radicle?
carbon tetrachloride
Provide an example of where free radicles are seen in physiological suituations:
neutrophils- they contain granules that contain oxidases that generate free radicles to attack the membrane of bacteria
Name the following in the diagram below:
- molecular oxygen
- superoxide anion
- hydrogen peroxide
- hydroxyl radical
- water
What are some examples of cellular free radical defense?
- All membranes have Vitamin E/A, B-carotene
- Mitchondria have SOD, glutahione peroxidase
- Peroxisomes have catalase
- Cytosol - SOD, Vitamin C, Glutathione peroxidase, Ferretin, Ceruloplasmin
What are the two different types of antioxidants that occur?
Enzymatic antioxidants: enzymes produced by the cell and inside the cell
Non-enzymatic antioxidants: work in two different ways - they can just completely block or they can act as a scavenger. They can make free radicle inert by donating an electron. This then produces a much less dangerous free radicle.
Name the enzymes in the reactions below:
- SOD
- catalse
- GSH-Px
What is the name of Se/Vitamin E deficiency in ruminants and what organs does it mainly affect?
Myocardial necrosis, skeletal muscle disease. Called white muscle disease
What are the signs of free radical disease that are commonly observed with Se/Vitamin E deficiency in poultry?
Encephalamalacia, haemorrhage
Vascular damage with haemorrhage/odema and muscle necrosis (esp.turkeys)
What are the signs of free radical-mediated diseases Se/vitamin E deficiency in pigs?
- Hepatic necrosis: hepatosis dietetica
- Vascular/myocardial necrosis - mulberry heart disease
What is the role of free radicles in inflammation?
Promote synethesis of cytokines, work synergistically to activate endothelial cells and exert toxic effects at sites of inflammation by reacting with cell components.
