energy metabolism Flashcards
this enzyme protects aerobic organisms from the product formed when one electron is transferred to a molecule of oxygen
superoxide dismutase
all of the following are true regarding cytochrome P450, EXCEPT
a nonheme protein
in the reaction which is the reductant
Fe2+ - Cu2+ –> Fe3+ - Cu1+
Fe2+ (Ferrous)
In the krebs cycle,
malate is oxidized 🡆oxaloacetate, wherein the electron carrier goes to complex 1 of the respiratory chain. the reaction is catalyzed by what oxidoreductase
pyridine-linked dehydrogenase (PYR-LD)
synthesis of ATP 🡰 ADP and inorganic phosphate by the free energy provided through hydrolysis of creatinine phosphate is an example of
substrate level phosphorylation
which of the following enzymes is inhibited by oligomycin?
ATP synthase
this subunit serves as proton channel in ATP synthase
F0 ATPase complex
which of these inhibitors uncouples the respiratory chain and oxidative phosphorylation
2,4 dinitophenol and pentachlorophenol
component of the respiratory chain which is NOT a proton pump
complex II
which of these protein complexes of the ETC is inhibited by malonate?
succinate- Q reductase
Standard G when ATP is hydrolyzed to ADP and Pi
-7.3 Kcal
which of the ff limit the rate of respiration at state 2
availability of substrate only
2nd law of thermodynamics states
the total entrophy of a system must increase if a process is to occur spontaneously
which of the ff limit rate of respiration ate state 4
availability of ADP only
which is not a site of energy conservation
complex II
the energy that phosphorylates ADP to ATP in complex V is called
Proton motive force
NADH dehydrogynase transfers electron to
FMN (flavin mononucleotide)
Vitamin B7
which ROS is acted upon by dismutase
superoxide anion
which of the ff enzymes is inhibited by malonic acid
NADH dehydrogenase
which protein complex is inhibited by amytal
complex I (amytal & rotenin =com I) (malonate=com II) (antimycin A= com III) (cyanide, hydrogen sulfide and carbon monoxide = com IV)
in what subunit of ATP synthase is ATP synthesized
BETA
in this reaction, which is the oxidant
Fe2+ - Cu2+ –> Fe3+ - Cu1+
Cu2+ (cupric ion)
how would you interpret a H that is negative
reaction releases heat
-H=exo= release heat
+H=endo=absorbed heat
P:O ratio if FADH2 is the electron carrier in the ETC
1.5
which protein complex is not a proton pump
succinate - Q reductase (complex IV)
cytochrome that transfer electrons directly to oxygen
Cytochrome a3
which of the ff protects the RBC from oxidative stress due to H202
glutathione peroxidase
what kind of oxidoreductase is cytochrome P450
Monooxygenase
what will be produced if molecular oxygen is reduced by 2 electrons
hydrogen peroxide
which inhibitor removes the link between ETC and oxidative phosphorylation?
dinitrophenol & pentachlorophenol (DTP, PCP)
what do you call the energy that is used to phosphorylate ADP to form ATP
proton-motive force
cyanide inhibits cytochrome oxidase binding to
cuprous Cu+= reducing agent (Cu2O)
what is the principal high energy intermediate or carrier compound
ATP
when H is Zero, the reaction is
isothermic
all of the following about the first law of thermodynamics are true, except
the total entrophy of a system must increase if a process is to occur spontaneously
which of the following thermodynamic concepts is correct
S is the degree of disorder
which of the ff is true if the G is negative
exergonic
amount of energy that is released from hydrolysis of ATP to ADP and Pi
-7.3 kcal/mol
the collecting point of electrons obtained from reduced NAD and FAD is
ubiquinone
what will be the consequence just in case NADP is not reduced to NADPH
decrease in the biosynthetic pathway at the level of reducatse
which if the ff enzyme incorporates an atom of oxygen 🡲 substrate 🡲 forming a hydroxylated product
monooxygenase
True about the 3rd law of thermodynamics
state known as “absolute zero” w/c is the bottom point on the kelvin temp scale
hydrolysis of ATP to ADP and Pi by the action of myosin ATPase releases energy which powered muscle contraction. this is made possible because according to the first law of thermodynamics
energy may be transformed into another form of energy
which of the following true if AG is positive
reaction is not spontaneous
how much energy is released when the beta high energy phosphate bond of ATP is cleaved to form AMP+PPi
G=-7.7 kcal/mol
a patient diagnosed with G-6PD deficiency is in danger of having hemolytic anemia because of increased levels of oxidative stress in his erythrocytes. normally the RBC has this enzyme which decomposes this toxic substance to water and oxygen
peroxidase
metabolism of lipophilic drugs is catalyzed by CP450 through hydroxylation which renders them water-soluble by
incorporating an atom of oxygen
one of the following oxidoreductase catalyzes the removal of hydrogen from a reduced substrate using NAD or FAD as intermediate electron acceptor
dehydrogenase
it uses 2 hydrogen peroxide as electron donor and electron acceptor
catalase
Cytochrome c links what protein complexes
complexes I and II to complex III
Synthesis of ATP through direct transfer of phosphate group from a high-energy substrate to ADP is called
substrate level phosphorylation
In the reaction: NADPH + GSSG → NADP + GSH.
Which is an oxidizing agent?
GSSG (glutathione disulfide)
Which of the following directly transfers electrons to oxygen?
Cytochrome a3
Which of the following removes the link between
the respiratory chain and oxidative phosphorylation?
2, 4-dinitrophenol
Which of the following protein complexes of the ETC produces one molecule of water?
Complex IV
The type of oxidoreductase that protects the body against damage by superoxide anion
dismutase
Transfer of 4 electrons to a molecule of oxygen results in the formation of
2 water molecules
Which of these conditions limit the rate of
respiration at state 4?
availability of ADP only
There is no translocation of proton in this protein complex of the ETC.
Complex II
The energy that phosphorylate ADP to ATP in
Complex V is called
proton motive force
In the respiratory chain, electrons from complexes I and II are transferred to
ubiquinone
NADH dehydrogenase uses this prosthetic group as electron acceptor in complex I
FMN
Transfer of one electron to one O2 molecule will produce
superoxide anion
Which protein complex of the respiratory chain is inhibited by malonate?
complex II
Which protein complex is inhibited by amytal?
complex I
What is the P:O ratio for FADH?
1.5
In what subunit of ATP synthase is ATP synthesized?
beta
