Term
| How is ATP formed in oxidative phosphorylation? |
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Definition
| NAD or FADH2, formed from oxidation of glucose and fatty acids, transfer electrons to O2 in a series of redox reactions to form ATP. |
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Term
| Where does oxidative phosphorylation occur? |
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Definition
| In the respiratory assemblies in the inner membrane of mitochondria |
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Term
| What drives ATP synthesis? |
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Definition
| The proton gradient across the inner mitochondrial membrane that is generated by the energy liberated from transfer of electrons |
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Term
| What is the outer mitochondrial membrane permeable to? |
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Definition
|
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Term
| What are the components of the inner mitochondrial membrane? |
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Definition
Respiratory electron carriers (complexes I-IV)
ADP-ATP translocase
ATP synthase
Other membrane transporters (such as proton channels and pumps) |
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Term
| True or false: the inner mitochondrial membrane is permeable to small molecules and ions. |
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Definition
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Term
| Which part of the mitochondrion carries a positive charge? |
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Definition
|
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Term
| Which part of the mitochondrion carries a negative charge? |
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Definition
|
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Term
| What is contained in the mitochondrial matrix? |
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Definition
Pyruvate dehydrogenase complex
Citric acid cycle enzymes
Fatty acid beta oxidation enzymes
Amino acid oxidation enzymes
DNA, ribosomes
Many other enzymes
ATP, ADP, Pi, Mg2+, Ca2+, K+
Many soluble metabolic intermediates |
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Term
| What enables coupling of redox reactions involving NADH and O2 to phosphorylation of ATP? |
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Definition
| Proton channels and pumps on the inner membrane. |
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Term
| What is used to provide free energy for the phosphorylation reaction of ADP to ATP? |
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Definition
| The charge difference between the negative matrix and positive intermembrane space that is set up by the redox reaction of NADH and O2 |
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Term
|
Definition
|
|
Term
|
Definition
|
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Term
| True or false: Free energy has to be positive to drive a reaction. |
|
Definition
| False. It has to be negative. |
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Term
| What causes electrons to be transported down the electron transport chain? |
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Definition
| Difference in reduction potential of electron carriers (from lower potential to higher potential) |
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Term
| Between what two types of carriers are electrons transferred spontaneously? |
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Definition
| From carriers whose reduction results in a small electrical potential change to carriers whose reduction results in increasingly larger electrical potential change |
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Term
What is the change in free energy for the overall reaction for the oxidation of NADH paired with the reduction of O2?
Is it spontaneous or non-spontaneous? |
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Definition
|
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Term
| What is another way of thinking of a hydrogen atom? |
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Definition
| As a proton and an electron |
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Term
| What are the five types of electron carriers in oxidative phosphorylation? |
|
Definition
NAD
Flavoproteins
Ubiquinone (Q)
Cytochromes
Iron-sulfur proteins |
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Term
| Which electron carriers can carry only one electron? |
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Definition
Cytochromes
Iron-sulfur proteins |
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Term
| Which electron carrier can carry only two electrons? |
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Definition
|
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Term
| Which electron carriers can carry one or two electrons, depending on the situation? |
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Definition
|
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Term
|
Definition
| A coenzyme found in all living cells that serves as a two electron donor. It carries electrons from catabolic reactions to the point of entry into the respiratory chain. Oxidixed substrate (R) + NADH + H+ -> NAD+ + reduced substrate (RH2)(backwards reaction as well) |
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Term
| Where do the two electrons go when NADH donates two electrons? |
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Definition
One goes to a proton to make atomic hydrogen
Other stripped off when its own hydrogen leaves
Oxidized substrate (R) + NADH + H+ -> Reduced substrate (RH2) + NAD+ |
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Term
| True or false: NAD can cross the inner mitochondrial membrane. |
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Definition
|
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Term
| What does NADH donate its two electrons to in Complex 1? |
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Definition
|
|
Term
| What donates electrons to ubiquinone/CoQ in Complex II? |
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Definition
|
|
Term
| What are the three redox states of Coenzyme Q10? |
|
Definition
Ubiquinone (Q) - fully oxidized
Ubisemiquinone (QH) - semiquinone
Ubiquinol (QH2) - fully reduced |
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Term
|
Definition
| A coenzyme that can accept one electron to from QH (semiquinone radical) or two electrons to form QH2 (ubiquinol). |
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Term
| Does ubiquinone usually accept one or two electrons? |
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Definition
|
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Term
| What is a special characteristic of ubiquinone that the other electron carriers do not share? |
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Definition
| It is hydrophobic and can diffuse within the lipid bilayer of the inner membrane. |
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Term
| What do flavoproteins and ubiquinone have in common? |
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Definition
| They can either participate in one- or two- electron transfers and can therefore act at the junction between a two-electron donor and a one-electron acceptor |
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Term
| What forms can FMN/FAD exist in? |
|
Definition
FMN/FAD - oxidized
FMNH/FADH - semiquinone
FMNH2/FADH2 - reduced |
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|
Term
| What does the reduction potential of flavin nucleotide depend on? |
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Definition
| The protein it's associated with |
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Term
|
Definition
| Proteins with heme groups that can accept one electron. There are three classes in mitochondria: a, b, and c. Type a and b (and some c) are integral inner membrane proteins. |
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Term
| In what sequence do electrons flow between electron carriers in terms of reduction potentional? |
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Definition
| In order of increasing reduction potential; electrons flow flow from carriers of lower electrial potential difference to carriers of higher electrical potential difference |
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Term
| What are iron-sulfur proteins? |
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Definition
| Proteins in which iron associates with inorganic sulfur atoms or sulfur atoms of Cys residues. They participate in one-electron transfers. |
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Term
| What type of iron-sulfur proteins have one Fe atom coordinated with two His residues? |
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Definition
| Rieske iron-sulfur proteins |
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Term
| Which complexes of oxidative phosphorylation have multiple Fe-S clusters? |
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Definition
|
|
Term
| What is the sequence of electron carriers in oxidative phosphorylation? |
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Definition
| NADH -> Q -> Cyt b -> Cyt c1 -> Cyt c -> Cyt (a+a3) -> O2 |
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Term
| Can the sequence of electron carriers in oxidative phosphorylation be spontaneously reversed? |
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Definition
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|
Term
| Which eight compounds inhibit electron transfer in oxidative phosphorylation? |
|
Definition
Cyanide
Carbon monoxide
Antimycin A
Myxothiazol
Rotenone
Amytal
Piericidin A
DCMU |
|
|
Term
| Which four compounds inhibit ATP synthase in oxidative phosphorylation? |
|
Definition
Aurovertin
Oligomycin
Venturicidin
DCCD |
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|
Term
| Which four compunds interfere with oxidative phosphorylation by uncoupling phosphorylation from electron transfer? |
|
Definition
FCCP
DNP
Valinomycin
Thermogenin |
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Term
| What compound interferes with oxidative phosphorylation by inhibiting ATP-ADP exchange? |
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Definition
|
|
Term
| Which compound inhibits adenine nucleotide translocase? |
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Definition
|
|
Term
| Which compounds target hydrophobic proton carriers? |
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Definition
|
|
Term
| Which compound targets K+ ionophore? |
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Definition
|
|
Term
| Which compound forms proton-conducting pores in the inner mitochondrial membrane in brown adipose tissue? |
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Definition
|
|
Term
| Which compound inhibits F1? |
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Definition
|
|
Term
| Which two compounds inhibit F0 and CF0? |
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Definition
|
|
Term
| Which compound blocks proton flow through F0 and CF0? |
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Definition
|
|
Term
| Which compound competes with QB for the binding site in PSII? |
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Definition
|
|
Term
| Which four compounds prevent electron transfer from FE-S center to Ubiquinone? |
|
Definition
Myxothiazol
Rotenone
Amytal
Piericidin A |
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Term
| Which compound blocks electron transfer from cytochrome b to cytochrome c1? |
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Definition
| Antimycin A. It binds to the Qi site of cytochrome c reductase, inhibiting the oxidation of ubiquinol. This disrupts the formation of the proton gradient across the inner membrane, disrupting ATP synthase, and also results in the formation of superoxide. |
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Term
| Which two compounds inhibit cytochrome oxidase (Complex IV)? |
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Definition
|
|
Term
| How are electron carriers organized in oxidative phosphorylation? |
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Definition
|
|
Term
| In which complex are electrons passed to ubiquinone via FMN and Fe-S proteins? |
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Definition
|
|
Term
| What are two other names for Complex I? |
|
Definition
NADH-CoQ reductase
NADH dehydrogenase |
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|
Term
| What is contained in the mitochondrial matrix? |
|
Definition
| Enzymes for the oxidation of amino acids, carbohydrates, and fatty acids |
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Term
| What types of molecules can be broken down for entry of electrons into oxidative phosphorylation? |
|
Definition
Carbohydrates
Fatty Acids
Amino acids |
|
|
Term
| What is another name for Complex I? |
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Definition
|
|
Term
| What is another name for complex II? |
|
Definition
|
|
Term
| What is another name for complex II? |
|
Definition
|
|
Term
| What is another name for Complex III? |
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Definition
|
|
Term
| What is another name for Complex IV? |
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Definition
|
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Term
| What is the only enzyme that participates in both the citric acid cycle and the electron transport chain? |
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Definition
|
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Term
| What is the name of the enzymes that catalyze reversible reactions with NAD+/NADP+? |
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Definition
| Nicotinamide nucleotide-linked dehydrogenases |
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Term
| Is NADH water soluble or lipid soluble? Are its reactions reversible? |
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Definition
|
|
Term
| Can NADH be carried across the inner mitochondrial membrane? |
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Definition
| No, but its electrons can be shuttled across. |
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Term
| Which electron carrier plays a central role in coupling electron flow to proton movement, as it carries both electrons and protons? |
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Definition
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|
Term
| Which electron carrier is a soluble protein that associates through electrostatic interactions with the outer surface of the inner mitochondrial membrane? |
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Definition
|
|
Term
| What are the only two mobile electron carriers in the electron transfer chain? |
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Definition
|
|
Term
| How are Rieske iron-sulfur proteins unique? |
|
Definition
| One Fe atom is coordinated to two His residues (not Cys) |
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|
Term
| How many Fe-S proteins function in electron transfer in mitochondria? |
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Definition
|
|
Term
| Besides entering through complexes I or II, how else can electrons be transferred to Q in ETC? |
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Definition
| Electrons from B oxidation of fatty acids can also enter through Q |
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Term
| What are the two components of the proton-motive force? |
|
Definition
1. Chemical PE (gradient of H+)
2. Electrical PE (separation of charge) |
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|
Term
| Can pH change the strength of the free energy released in ETC ? |
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Definition
|
|
Term
|
Definition
|
|
Term
| What does superoxide dismutase catalyze? |
|
Definition
Superoxide and protons to peroxide and oxygen
2 .O2- + 2H+ ---> H2O2 + O2 |
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|
Term
| Which enzyme in ETC contains copper? |
|
Definition
| Cytochrome oxidase (Complex IV) |
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|
Term
| Can ATP synthesis occur without electron transfer, or vice versa? |
|
Definition
|
|
Term
| What part of ATP synthase makes ATP? |
|
Definition
|
|
Term
| What part of ATP synthase keeps the proton gradient working? |
|
Definition
|
|
Term
| What allows ATP to dissociate from F1? |
|
Definition
| Release of free energy caused by H+ flowing down its conc gradient |
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|
Term
| How many ATP are synthesized per one rotation of F0? |
|
Definition
|
|
Term
| How many ADP are moved in for every ATP moved out by adenine nucleotide translocase? |
|
Definition
|
|
Term
| What is the P/O ratio for NADH? |
|
Definition
|
|
Term
| What is the P/O ratio for FADH2/succinate? |
|
Definition
|
|
Term
| What is indicated by the P/O ratio? |
|
Definition
| The nummber of ATP's made per 2 electrons passed down ETC and each O atom consumed by mit. resp. |
|
|
Term
| How many protons are required to make 1 ATP? |
|
Definition
|
|
Term
| How many degrees does F0 have to rotate through to make 1 ATP? |
|
Definition
|
|
Term
| How is phosphate transported into the matrix? |
|
Definition
| By moves HPO4(2-) through the phosphate transporter |
|
|
Term
| What is the malate-aspartate shuttle? |
|
Definition
Asp -> OAA -> Malate oxidizes NADH
Mal -> OAA -> Asp reduces NAD+
It transfer's e-'s from NAD+ to NADH without moving NAD+/NADH across the inner mit membrane
Glutamate, transaminase, and malate dehydrogenase are also involved |
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|
Term
| What role does the glycerol 3-phosphate shuttle play in ETC? |
|
Definition
| Glycolysis oxidizes NAD+,DHAP is converted to G-3-P. G-3P is converted back into DHAP, which converts FAD to FADH2, which contributes electrons to QH@ in ETC. The electrons enter at complex III. |
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|
Term
| How does thermogenin uncoupling protein work? |
|
Definition
| It is a pore that allows H+ to flow back into matrix. This uncouples ATP synthesis from electron transfer and the energy produced from ETC is released as heat. |
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