BioChem - Module 7 - Generation of Energy, Module
7, Mod7,8, Medical Biochemistry Unit 1 Exam, Week
2 Evaluation, Pre-Evaluation Question Bank, 1
Dinitrophenol is an example of an: correct answer: uncoupler
Explanation: DNP is an uncoupler of the electron transport chain
dissipating the proton gradient across the inner mitochondrial
membrane.
Succinate is a substrate for which complex in the electron
transport chain? correct answer: Complex II
Explanation: Complex II or Succinate dehydrogenase is coupled
to the TCA cycle and accepts succinate rather than malate as a
substrate.
The oxidation of double bonds is coupled to correct answer:
reduction of FAD
Explanation: The oxidation of double bonds is most commonly
coupled to the reduction of FAD because FAD can accept two
electrons. NAD+ is usually coupled with the oxidation of
alcohols as it can accept one electron.
An example of mechanical work is: correct answer: the energy
required to change the conformation of hemoglobin
Mechanical work is best described as the conversion of a high
energy bond, such as that in an ATP bond, to instigate a
conformational change in a protein. See figure 19.4
,The last cytochrome in the ETC, cytochrome oxidase, passes
electrons to O2. Cytochrome oxidase is able to do this because it
has: correct answer: lower Km for oxygen then hemoglobin
Explanation: The lower Km for oxygen allows cytochrome
oxidase to 'pull' oxygen from myoglobin and hemoglobin,
additionally it is bound to copper ions that allows for the
collection of 4 electrons required for the reduction of oxygen.
All of the components of the electron transport chain are bound
to the mitochondrial membrane except: correct answer: Co Q
Explanation: CoQ is the only mobile component of the ETC, its
ability to accept both electrons and protons is unique to this part
of the ETC.
In the case of an exothermic reaction: correct answer: ΔG0
would be negative
Explanation: A negative ΔG0 is indicative of a spontaneous
reaction. ΔS is the change in entropy or an increase in disorder,
this value is often negligible.
A ΔG0 that is negative is what kind of reaction? correct answer:
Favorable, Exergenic, releases energy
A ΔG0 that is positive is what kind of reaction? correct answer:
Unfavorable, Endergenic
At eliquilrium the ΔG0 has what properties? correct answer: the
rate of product formation and dissosication is equal
,Which of hte following is a true statement with regards to
determining the direction of the reaction? correct answer: A
reaction can become favorable if the product/substrate ratio
becomes low enough
Which complexes make up the oxidative pathway? correct
answer: I, III, IV
Which complex makes up the phosphorylation pathway? correct
answer: V - ATP synthase
LER correct answer: Loss of Electrons - Oxidation
GER correct answer: Gain of Electrons - Reduction
What are the 3 ways to oxidize compounds? correct answer: 1)
Transfer of electrons from the compound as a hydrogen or
hydride
2) direct addition of oxygen
3) direct donation of electrons
What are the two currencies of energy? correct answer: FAD -
formation of double bonds
NAD - Oxidation of alcohols
ΔE0 is correct answer: the energy change when a compound
becomes reduced.
the more negative, the more energy there is to make ATP
Negative ΔE0 is correct answer: the energy change when a
compound becomes oxidized.
, Complex I is comprised of correct answer: NADH:CoQ
oxidoreductase
Binding site for flavenmononueclotide (FMN) and iron sulfur
(Fe-S) center. Electrons from NADH pass to FMN -> FeS ->
electrons to CoQ, moves 4 electrons to the intermembrane
4H+ protons.
Complex III is comprised of correct answer: Cytochrome b-c1
complex
uses Heme Fe complex to transfer electrons: Fe3+ reduced
(oxidized) to Fe2+
Complex IV is comprised of correct answer: Cytochome
oxidase
Last cytochrome must transfer 4 electrons to Oxygen using a
copper ion (Cu+). Oxygen is the final acceptor in the ETP chain
Complex V is comprised of correct answer: ATP synthase
CoQ correct answer: is a quinone. with a free electron is is a
free radical. in it's fully reduced form it accepts an electron and
protons (dihydroquinol).
enzyme CoQ is the only non bound protein in the protein
complex adn can accept electrons from both Complex I and II.
Complex II correct answer: binds FADH, part of TCA cycle
is not transmembrane and can not pump protons
7, Mod7,8, Medical Biochemistry Unit 1 Exam, Week
2 Evaluation, Pre-Evaluation Question Bank, 1
Dinitrophenol is an example of an: correct answer: uncoupler
Explanation: DNP is an uncoupler of the electron transport chain
dissipating the proton gradient across the inner mitochondrial
membrane.
Succinate is a substrate for which complex in the electron
transport chain? correct answer: Complex II
Explanation: Complex II or Succinate dehydrogenase is coupled
to the TCA cycle and accepts succinate rather than malate as a
substrate.
The oxidation of double bonds is coupled to correct answer:
reduction of FAD
Explanation: The oxidation of double bonds is most commonly
coupled to the reduction of FAD because FAD can accept two
electrons. NAD+ is usually coupled with the oxidation of
alcohols as it can accept one electron.
An example of mechanical work is: correct answer: the energy
required to change the conformation of hemoglobin
Mechanical work is best described as the conversion of a high
energy bond, such as that in an ATP bond, to instigate a
conformational change in a protein. See figure 19.4
,The last cytochrome in the ETC, cytochrome oxidase, passes
electrons to O2. Cytochrome oxidase is able to do this because it
has: correct answer: lower Km for oxygen then hemoglobin
Explanation: The lower Km for oxygen allows cytochrome
oxidase to 'pull' oxygen from myoglobin and hemoglobin,
additionally it is bound to copper ions that allows for the
collection of 4 electrons required for the reduction of oxygen.
All of the components of the electron transport chain are bound
to the mitochondrial membrane except: correct answer: Co Q
Explanation: CoQ is the only mobile component of the ETC, its
ability to accept both electrons and protons is unique to this part
of the ETC.
In the case of an exothermic reaction: correct answer: ΔG0
would be negative
Explanation: A negative ΔG0 is indicative of a spontaneous
reaction. ΔS is the change in entropy or an increase in disorder,
this value is often negligible.
A ΔG0 that is negative is what kind of reaction? correct answer:
Favorable, Exergenic, releases energy
A ΔG0 that is positive is what kind of reaction? correct answer:
Unfavorable, Endergenic
At eliquilrium the ΔG0 has what properties? correct answer: the
rate of product formation and dissosication is equal
,Which of hte following is a true statement with regards to
determining the direction of the reaction? correct answer: A
reaction can become favorable if the product/substrate ratio
becomes low enough
Which complexes make up the oxidative pathway? correct
answer: I, III, IV
Which complex makes up the phosphorylation pathway? correct
answer: V - ATP synthase
LER correct answer: Loss of Electrons - Oxidation
GER correct answer: Gain of Electrons - Reduction
What are the 3 ways to oxidize compounds? correct answer: 1)
Transfer of electrons from the compound as a hydrogen or
hydride
2) direct addition of oxygen
3) direct donation of electrons
What are the two currencies of energy? correct answer: FAD -
formation of double bonds
NAD - Oxidation of alcohols
ΔE0 is correct answer: the energy change when a compound
becomes reduced.
the more negative, the more energy there is to make ATP
Negative ΔE0 is correct answer: the energy change when a
compound becomes oxidized.
, Complex I is comprised of correct answer: NADH:CoQ
oxidoreductase
Binding site for flavenmononueclotide (FMN) and iron sulfur
(Fe-S) center. Electrons from NADH pass to FMN -> FeS ->
electrons to CoQ, moves 4 electrons to the intermembrane
4H+ protons.
Complex III is comprised of correct answer: Cytochrome b-c1
complex
uses Heme Fe complex to transfer electrons: Fe3+ reduced
(oxidized) to Fe2+
Complex IV is comprised of correct answer: Cytochome
oxidase
Last cytochrome must transfer 4 electrons to Oxygen using a
copper ion (Cu+). Oxygen is the final acceptor in the ETP chain
Complex V is comprised of correct answer: ATP synthase
CoQ correct answer: is a quinone. with a free electron is is a
free radical. in it's fully reduced form it accepts an electron and
protons (dihydroquinol).
enzyme CoQ is the only non bound protein in the protein
complex adn can accept electrons from both Complex I and II.
Complex II correct answer: binds FADH, part of TCA cycle
is not transmembrane and can not pump protons
