Quan Flashcards
Is oxygen inert or reactive at body temperature?
inert at body temperature, but highly reactive at high temperatures
Most of the oxygen usage is committed to
oxidative phosphorylation (90%)
oxidation is the ____ of electrons or and ____ in oxidation state by a molecule/atom
loss of electrons, increase in oxidation
Reduction is the ____ of electrons or and ____ in oxidation state by a molecule/atom
gain of electrons, decrease in oxidation
free redox active metal ions are usually ____?
generally sequestered (hidden away)
_________ are partially reduced, reactive forms of oxygen
ROS (Reactive oxygen species)
The main ROS you should know:
H202
superoxide
hypochlorite ion
OH radical (OH is the most reactive and damaging!)
What is a radical?
also called a free radical, is a cluster of atoms, one of which contains an unpaired electron in the outermost shell of electrons; thus radicals are extremely unstable and quickly react with others
The three ways of formation of a ROS:
1) O2 with reactive metal
2) in mitochondrial electron transfer reactions
3) enzymatic reaction
Fenton reaction
Fe+2 + H2O2 —>
Fe+3 + OH` + OH-
note: OH`= OH with an unpaired electron = radical!
Oxidative stress is balanced by:
ROS producing factors and antioxidants
________ is generated during ischemia/reperfusion. Results from the disruption of the _______.
Oxidative stress; electron transfer chain
ROS damages cell membrane by interacting with ___________ to create ________.
polyunsaturated fatty acids to create lipid peroxide
ROS damages DNA by causing ______ to break
DNA
ROS oxidize ________ to damage protein function
amino acids
ROS are also important for the production of ______ and for the killing of _______
bio-active molecules and killing of bavcterial
A critical enzyme in bacteral killing is
myeloperoxidase