NHM 454 Exam 2 Questions with Detailed
Verified Answers
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
,2 | Page
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
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
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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)
, 4 | Page
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:
Verified Answers
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
,2 | Page
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
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
,3 | Page
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)
, 4 | Page
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:
