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)
are strong oxidants and can be beneficial
detrimental at high levels
, NHM 454 EXAM 2 QUESTIONS WITH COMPLETE SOLUTIONS 2025!!
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
phagocytic cells
(these sources cant be avoided and diet must compensate)
What do peroxisomes do? - (answer)breaks down fatty acids