NHM 454 Exam 2 Questions with Correct Answers Latest Update 2025-2026
What determines if a compound can act as an antioxidant? - Answers 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? - Answers involves the transfer of oxygen,
hydrogen, or electrons
What is oxidation and reduction reactions commonly referred to as? - Answers redox reactions
What is an antioxidants? - Answers substances which markedly delay or prevent the oxidation
of a substrate
Resonance stability - Answers stability of antioxidant after it donates either a H+ or e-
What are the antioxidant actions in a compound? - Answers 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? - Answers gain of oxygen --- loss of oxygen
What is redox reaction by H transfer? - Answers oxidation = loss of a hydrogen ---- reduction =
gain of a hydrogen
What is redox reaction by electron transfer? - Answers oxidation = loss of electrons --- reduction
= gain of electrons
Most common type of redox reaction? - Answers By transfer of H+
H+ to be extracted from protein, lipid, DNA
Hydrogen Atom Transfer Mechanism - Answers H+ have to be added to the compound that was
oxidized in order to stabilize it
What is the compound stability based on? - Answers the instability of the valence shell is in free
radicals and where antioxidants come in
What can be a free radical? - Answers ANY compound that has lost an e- from its valence shell
Can an O2 become a free radical? How? - Answers 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? - Answers 2-5% of
oxygen in gneeration of ATP
What is a source of oxidative stress? Why? Quenches this stress? - Answers exercise is a
source of oxidative stress due to increase O2 intake --- food quenches it
What is superoxide? - Answers an oxygen that became a free radical due to the unpaired
valence electron in its outer cell
What is ROS? - Answers reactive oxidative species
free radicals containing O2 (w/ unpaired e- in outer shell)
are strong oxidants and can be beneficial
detrimental at high levels
What are examples of ROS? - Answers hydroxyl radical, singlet oxygen, hydrogen peroxide,
peroxyl radical, etc.
What does excess ROS do? - Answers overwhelms protective enzymes resulting in oxidative
stress (destroying tissues/disrupting DNA)
What is the most potent radical? - Answers oxygen
What are endogenous antioxidant enzymes? - Answers superoxide dismutase
gluathione peroxidase
catalase
glutathone reductase
*produced based on amnt of BASAL oxidative stress*
What were endogenous antioxidant enzymes created for? - Answers By body to:
-quench the radicals created to aeorbic respiration
-detoxify/breakdown oxidative species
What causes disease onset? - Answers increase oxidative stress and inadequate diet
What are endogenous source for free radicals? - Answers aerobic respiration
peroxisomes
cytochrome P450
What determines if a compound can act as an antioxidant? - Answers 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? - Answers involves the transfer of oxygen,
hydrogen, or electrons
What is oxidation and reduction reactions commonly referred to as? - Answers redox reactions
What is an antioxidants? - Answers substances which markedly delay or prevent the oxidation
of a substrate
Resonance stability - Answers stability of antioxidant after it donates either a H+ or e-
What are the antioxidant actions in a compound? - Answers 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? - Answers gain of oxygen --- loss of oxygen
What is redox reaction by H transfer? - Answers oxidation = loss of a hydrogen ---- reduction =
gain of a hydrogen
What is redox reaction by electron transfer? - Answers oxidation = loss of electrons --- reduction
= gain of electrons
Most common type of redox reaction? - Answers By transfer of H+
H+ to be extracted from protein, lipid, DNA
Hydrogen Atom Transfer Mechanism - Answers H+ have to be added to the compound that was
oxidized in order to stabilize it
What is the compound stability based on? - Answers the instability of the valence shell is in free
radicals and where antioxidants come in
What can be a free radical? - Answers ANY compound that has lost an e- from its valence shell
Can an O2 become a free radical? How? - Answers 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? - Answers 2-5% of
oxygen in gneeration of ATP
What is a source of oxidative stress? Why? Quenches this stress? - Answers exercise is a
source of oxidative stress due to increase O2 intake --- food quenches it
What is superoxide? - Answers an oxygen that became a free radical due to the unpaired
valence electron in its outer cell
What is ROS? - Answers reactive oxidative species
free radicals containing O2 (w/ unpaired e- in outer shell)
are strong oxidants and can be beneficial
detrimental at high levels
What are examples of ROS? - Answers hydroxyl radical, singlet oxygen, hydrogen peroxide,
peroxyl radical, etc.
What does excess ROS do? - Answers overwhelms protective enzymes resulting in oxidative
stress (destroying tissues/disrupting DNA)
What is the most potent radical? - Answers oxygen
What are endogenous antioxidant enzymes? - Answers superoxide dismutase
gluathione peroxidase
catalase
glutathone reductase
*produced based on amnt of BASAL oxidative stress*
What were endogenous antioxidant enzymes created for? - Answers By body to:
-quench the radicals created to aeorbic respiration
-detoxify/breakdown oxidative species
What causes disease onset? - Answers increase oxidative stress and inadequate diet
What are endogenous source for free radicals? - Answers aerobic respiration
peroxisomes
cytochrome P450
