Unit 2 Objective_AI
Module7
1. Define and briefly explain the role of entropy, and enthalpy in biochemical
reactions
Entropy
o Disorder in a reaction
o Every reaction tends towards a state of disorder
Enthalpy
o Heat in a reaction
2. Give examples of biochemical, mechanical and transport work.
Mechanical Work
o Movement of an enzyme; conformation change in Enzyme (Hgb)
o Charging of the myosin head group.
Transport Work
o ATPases
o Na/K transport (Module 2) (req’s ATP to move shit)
Biochemical work – Main focus of this module.
o Energy of reactions
o Synthesis of large molecules from smaller compounds., proteins
3. Calculate the overall delta G of a series of reactions if given the delta G for each
individual reaction
Delta G knot = Negative (-)
o Exergonic, favorable reaction
Delta G knot = Positivie (+)
o Energonic, unfavorable reaction, requiring energy.
In conjuction with P/S ratio (=Keq)
o Decrease in the ratio of P/S provides a driving force for the reaction to move in
the forward direction.
4. Describe the role of ATP as an energy carrier, specifically the role of the high
energy phosphate bonds (Figure 19.2)
, It does so with high energy phosphor-anhydride bonds.
o Phosphate groups are negatively charged.
ATP has 3 neg charges, highly unstable and want to repel.
We couple the cleavage of the phosphor-anhydride bond with a reaction requiring less
energy, in order for that reaction to happen.
5. Compare the redox coenzymes, FAD, NAD and NADPH as the cell's electron
carriers (Figure 19.9, 19.10)
All synthesized through fuels in Phase 1 of resp.
NAD+ accepts 2 electrons as a hydride ion
o Reduction of NAD+
Releases a proton into the medium.
FAD involved in the formation of double bonds
FAD can accept 2 electrons as hydrogen atoms, separately.
The Electrons from NADH are passed to the flavinmononucleotide, and the flavin
mononucleotide passes those 2 electrons individually to the iron-sulfur center within
the protein.
Complex 1 = NADH
Complex 2 = FADH
6. Define oxidation, reduction, reducing agent and oxidizing agent.
Oxidation
o Loss of Electrons
Reduction
o Gain of Electrons
Reducing agent
o Losses or donates electrons
Oxidizing Agent
o Gains or accepts electrons
7. Describe the purpose of Complexes I, III, and IV in oxidative phosphorylation and
ATP synthase in ATP generation (Figure 21.1).
, 3 complexes responsible for pumping of protons across the mitochondrial membrane
Complex 1 or NADH oxidoreductase
o Binds NADH and receives 2 electrons to it’s FMN, then sends the 2 E’s to the Fe-S
center.
o Fe-S center can transfer E’s to CoQ
This moves 4 protons to the intermembrane space.
Complex 3 or Cytochrome b-c1
o Cytochromes uses Heme Fe Complex to transfer electrons:
Fe3+ reduced to Fe2+ as electrons move down the chain.
The Heme prosthetic group differs slightly in that the redox potential is
maintained as electrons are transported down the proteins.
Complex IV cytochrome oxidase
o Last cytochrome must transfer 4 electrons to oxygen (final acceptor of the chain)
Does this using copper ion.
8. Relate the proton motive force to the pH on either side of the mitochondrial membrane
(Figure 21.2)
The electrochemical potential is called the proton motive force because it
represents the potential energy driving protons to return to the more negative
charged alkaline matrix.
9. Describe the role of Complex II (succinate dehydrogenase) in the electron transport chain
(Figure 21.5)
Binds FADH
Also part of the TCA cycle
Transfer electrons to CoQ
It does not span the membrane so has no proton pumping ability like the other
complexes.
Electrons from FADH are again transferred to an Fe-S center then again to CoQ.
Again, the transfer of electrons has facilitated the pumping of protons to the Cytosol,
OUT of the mitochondria.
10. Discriminate between electron transport inhibitors and uncouplers of oxidative
phosphorylation
Inhibitors
o Inhibitor BLOCKS electron transport = NO ATP generation
Uncouplers
o Dissrupts membrane, allows H+ back into the matrix but still allows e- to
transport, increasing O2 consumption.
o Dissipates the proton gradient = NO ATP Generation
o Increase in O2 consumption due to free e- movement.
Module7
1. Define and briefly explain the role of entropy, and enthalpy in biochemical
reactions
Entropy
o Disorder in a reaction
o Every reaction tends towards a state of disorder
Enthalpy
o Heat in a reaction
2. Give examples of biochemical, mechanical and transport work.
Mechanical Work
o Movement of an enzyme; conformation change in Enzyme (Hgb)
o Charging of the myosin head group.
Transport Work
o ATPases
o Na/K transport (Module 2) (req’s ATP to move shit)
Biochemical work – Main focus of this module.
o Energy of reactions
o Synthesis of large molecules from smaller compounds., proteins
3. Calculate the overall delta G of a series of reactions if given the delta G for each
individual reaction
Delta G knot = Negative (-)
o Exergonic, favorable reaction
Delta G knot = Positivie (+)
o Energonic, unfavorable reaction, requiring energy.
In conjuction with P/S ratio (=Keq)
o Decrease in the ratio of P/S provides a driving force for the reaction to move in
the forward direction.
4. Describe the role of ATP as an energy carrier, specifically the role of the high
energy phosphate bonds (Figure 19.2)
, It does so with high energy phosphor-anhydride bonds.
o Phosphate groups are negatively charged.
ATP has 3 neg charges, highly unstable and want to repel.
We couple the cleavage of the phosphor-anhydride bond with a reaction requiring less
energy, in order for that reaction to happen.
5. Compare the redox coenzymes, FAD, NAD and NADPH as the cell's electron
carriers (Figure 19.9, 19.10)
All synthesized through fuels in Phase 1 of resp.
NAD+ accepts 2 electrons as a hydride ion
o Reduction of NAD+
Releases a proton into the medium.
FAD involved in the formation of double bonds
FAD can accept 2 electrons as hydrogen atoms, separately.
The Electrons from NADH are passed to the flavinmononucleotide, and the flavin
mononucleotide passes those 2 electrons individually to the iron-sulfur center within
the protein.
Complex 1 = NADH
Complex 2 = FADH
6. Define oxidation, reduction, reducing agent and oxidizing agent.
Oxidation
o Loss of Electrons
Reduction
o Gain of Electrons
Reducing agent
o Losses or donates electrons
Oxidizing Agent
o Gains or accepts electrons
7. Describe the purpose of Complexes I, III, and IV in oxidative phosphorylation and
ATP synthase in ATP generation (Figure 21.1).
, 3 complexes responsible for pumping of protons across the mitochondrial membrane
Complex 1 or NADH oxidoreductase
o Binds NADH and receives 2 electrons to it’s FMN, then sends the 2 E’s to the Fe-S
center.
o Fe-S center can transfer E’s to CoQ
This moves 4 protons to the intermembrane space.
Complex 3 or Cytochrome b-c1
o Cytochromes uses Heme Fe Complex to transfer electrons:
Fe3+ reduced to Fe2+ as electrons move down the chain.
The Heme prosthetic group differs slightly in that the redox potential is
maintained as electrons are transported down the proteins.
Complex IV cytochrome oxidase
o Last cytochrome must transfer 4 electrons to oxygen (final acceptor of the chain)
Does this using copper ion.
8. Relate the proton motive force to the pH on either side of the mitochondrial membrane
(Figure 21.2)
The electrochemical potential is called the proton motive force because it
represents the potential energy driving protons to return to the more negative
charged alkaline matrix.
9. Describe the role of Complex II (succinate dehydrogenase) in the electron transport chain
(Figure 21.5)
Binds FADH
Also part of the TCA cycle
Transfer electrons to CoQ
It does not span the membrane so has no proton pumping ability like the other
complexes.
Electrons from FADH are again transferred to an Fe-S center then again to CoQ.
Again, the transfer of electrons has facilitated the pumping of protons to the Cytosol,
OUT of the mitochondria.
10. Discriminate between electron transport inhibitors and uncouplers of oxidative
phosphorylation
Inhibitors
o Inhibitor BLOCKS electron transport = NO ATP generation
Uncouplers
o Dissrupts membrane, allows H+ back into the matrix but still allows e- to
transport, increasing O2 consumption.
o Dissipates the proton gradient = NO ATP Generation
o Increase in O2 consumption due to free e- movement.
