Although non-enzymatic oxidation is possible in juice and must, the affinity of PPO for molecular oxygen
effectively prevents chemical oxidation.
Oxidative stress and lipid peroxidation: Lipid peroxidation basically consists of the incorporation of molecular oxygen
into a poly-unsaturated fatty acid, resulting in oxidative degradation of the later.
In our study, the absorbance measurements were different in untreated and chromotized sampl .Reduction of molecular oxygen
to superoxide, and of peroxide to hydroxyl radicals is "spin forbid-den" and thus is slow unless catalyzed by a heavy ion .
The intense exercise is related to higher consumption of molecular oxygen
([O.sub.2]) and resulting increased generation of ROS in cells and tissues [18-20].
undergoes photolysis to give oxygen atoms, which in the presence of an inert body (M) reacts with more oxygen to give ozone.
Then the electron transfer reaction [Q.sup.8-] + 02 [right arrow] Q + 02 converts molecular oxygen
into superoxide anion.
It catalyzes the oxidation of b-glucose to glucono-1,5-lactone, which spontaneously hydrolyzes nonenzymatically to gluconic acid, using molecular oxygen
and releasing hydrogen peroxide.
Each chlorine atom can convert up to 100,000 molecules of ozone to molecular oxygen
. The depletion of the Earth's ozone layer has reached record levels, especially in polar regions.
In photosynthetic systems, the ubiquitous chlorophyll molecule is involved in the harvesting of light energy, the transfer of this energy and the primary electron transfer events that culminate in the release of molecular oxygen
, all without a change in the molecule's geometric structure.
This was first made evident when significant levels of molecular oxygen
were detected in a medium containing the discharging spores.
3 The single oxygen atom combines with molecular oxygen
(O2) in the air to form three atoms of oxygen, or ozone (O3): O + O2 = 03
Air flows between the panels, and the radio frequency dissociates molecular oxygen
into atomic oxygen.
This initiates an electron flux from NADPH via the activated phox to molecular oxygen
leading to the generation of superoxide (4).
Ozone is the unstable molecule formed by three atoms of oxygen, one atom more than molecular oxygen
. That extra oxygen atom is just enough to transform the very gas that is required by all aerobic life forms into a deadly oxidizing agent that, in sufficient concentration, can kill most anything.
Today, our cells contain active remnants of those bacteria in the form of organelles known as mitochondria, which we use to extract us-able forms of biological energy from food and molecular oxygen