What determines if a compound can act as an antioxidant? - (answer)if a compound can
donate a hydrogen or electron and not become a radical itself, it is a compound with
antioxidant potential. It is all about the chemical structure of the compound.
What does oxidation and reduction reactions involve? - (answer)involves the transfer of
oxygen, hydrogen, or electrons
What is oxidation and reduction reactions commonly referred to as? - (answer)redox
reactions
What is an antioxidants? - (answer)substances which markedly delay or prevent the
oxidation of a substrate
Resonance stability - (answer)stability of antioxidant after it donates either a H+ or e-
What are the antioxidant actions in a compound? - (answer)3 ways: 1) they can donate
hydrogen or electon to a free radical;; 2) bind metals or compounds that can initate
oxidation;; 3)antioxidant can bind to free radical (servces as stabilizer)
What is oxidation by O2? reduction? - (answer)gain of oxygen --- loss of oxygen
What is redox reaction by H transfer? - (answer)oxidation = loss of a hydrogen ----
reduction = gain of a hydrogen
What is redox reaction by electron transfer? - (answer)oxidation = loss of electrons ---
reduction = gain of electrons
Most common type of redox reaction? - (answer)By transfer of H+
H+ to be extracted from protein, lipid, DNA
,NHM 454 EXAM 2 QUESTIONS WITH COMPLETE SOLUTIONS 2025!!
Hydrogen Atom Transfer Mechanism - (answer)H+ have to be added to the compound
that was oxidized in order to stabilize it
What is the compound stability based on? - (answer)the instability of the valence shell is
in free radicals and where antioxidants come in
What can be a free radical? - (answer)ANY compound that has lost an e- from its valence
shell
Can an O2 become a free radical? How? - (answer)Yes becuase of their role in generation
of ATP -- terminal electron acceptor in mitochondria that in its ground state, oxygen has
two unpaired electrons in outer shell. electrons have the same spin, so oxygen can only
receive one electron at a time int he ETC. the rate of the elctrons in ETC stomeimes slows
or speeds --> free electron linkage occurs. when they link the readily bind oxygen, if the
rate excessed the ability of oxygen to bind, free radicals will form due to a leark OR
superoxide can form from the slowing flow that causes a oxygen to spin out with one free
valence electron in cell
How much of oxygen results in production of reactive oxygen species? - (answer)2-5% of
oxygen in gneeration of ATP
What is a source of oxidative stress? Why? Quenches this stress? - (answer)exercise is a
source of oxidative stress due to increase O2 intake --- food quenches it
What is superoxide? - (answer)an oxygen that became a free radical due to the unpaired
valence electron in its outer cell
What is ROS? - (answer)reactive oxidative species
free radicals containing O2 (w/ unpaired e- in outer shell)
, NHM 454 EXAM 2 QUESTIONS WITH COMPLETE SOLUTIONS 2025!!
are strong oxidants and can be beneficial
detrimental at high levels
What are examples of ROS? - (answer)hydroxyl radical, singlet oxygen, hydrogen
peroxide, peroxyl radical, etc.
What does excess ROS do? - (answer)overwhelms protective enzymes resulting in
oxidative stress (destroying tissues/disrupting DNA)
What is the most potent radical? - (answer)oxygen
What are endogenous antioxidant enzymes? - (answer)superoxide dismutase
gluathione peroxidase
catalase
glutathone reductase
*produced based on amnt of BASAL oxidative stress*
What were endogenous antioxidant enzymes created for? - (answer)By body to:
-quench the radicals created to aeorbic respiration
-detoxify/breakdown oxidative species
What causes disease onset? - (answer)increase oxidative stress and inadequate diet
What are endogenous source for free radicals? - (answer)aerobic respiration
peroxisomes
cytochrome P450