Oxygen can be toxic
Which of theses are reasons that oxygen is essential?
Oxidation reactions
Generation of ATP (oxidative phosphorylation)
Detoxification reactions
Anaerobic glycolysis
Bio synthetic reactions
Why is oxygen classified as toxic?
When it accepts single electrons it is transformed into highly reactive oxygen radicals than can damage things.
When it accepts double electrons it is transformed into highly reactive oxygen radicals than can damage things.
When it accepts single electrons it is transformed into non-reactive oxygen radicals than can damage things.
It takes part in unnecessary reactions
What do oxygen radicals damage?
Cellular lipids
Proteins
DNA
Glucose
Starch
What are the major sources of primary ROS in the cell?
CoQ generates superoxide in ETC
Respiration in lungs
Oxidase, oxygenates and peroxidases
Ionizing radiation
Non-ionizing radiation
Where can evidence of free radical damage be seen?
>100 disease states
<100 disease states
>1000 disease states
Where is evidence of free radical damage in disease states described?
As primary cause of the disease
By enhancing complications
In the lumen of cells
Superoxide and the hydroxyl radical Initiate lipid peroxidation in..
Cellular membrane
Mitochondrial membrane
Nuclear membrane
ER membrane
Increase in membrane permeability due to radical-mediated damage leads to..
A further influx of ca2+
Repair of the mtiochondria
Ca2+ leaving the cell
Further escaping of radicals
Oxidation of nuclear and mitochondrial DNA results in ...
Strand breaks
Various damages
RNOS
Influx of Ca2+
Disruption of the mitochondrial membrane may augment free radical damage
Oxygen derived free radicals are a minor source of DNA damage
The non-specific binding of Fe2+ to DNA...
facilitates localized production of the hydroxyl radical
Can attack the deoxyribose backbone
Can cause strand breaks
Will cause apoptosis
Can be protective
At high concentrations nitrogen combines with oxygen or superoxide to form reactive and toxic species which contain both N and O.
RNOS’s are implicated in ...
Neurodegenerative diseases
Chronic inflammatory diseases
Hay fever
Alcoholism
Hunger
What are some of the consequences of high concentrations of NO during inflammation?
Inhibition of enzymes
Mitochondrial lipid peroxidation
Inhibition of ETC and energy depletion
Single or double strand breaks in DNA
Modification of bases in DNA
