oxidative phosphorylation
chemically removing protons from the matrix
reduction of CoQ and reduction of oxygen
energy needed to phosphorylate ADP is provided by the
flow of protons down the electrochemical gradient
cristae
foldings of inner membrane of mitochondria
protons are pumped
from mitochondrial matrix into the inter membrane space
matrix is inside
inner membrane
oxidative phosphorylation occurs where
inner mitochondrial membrane
where is ETC
inner mitochondrial membrane
inner mitochondria membrane charges of inner and outer due to etc *recheck slide
inner= + outer= - matrix- neg charge
pyruvate is moved where in presence of what it does what then
into mitochondrial matrix in presence of O2 undergoes oxidative decarboxylation producing acetyl co-a
citric acid cycle produces atp or gtp
either depending on cell location
how many atp for every turn of CAC how many CO2
1 ATP 2 CO2 (we breathe out)
3 stages cell respiration
1. foods- acetyl coA 2. CAC- co2 released, 2 units of acetyl coA oxidized from CAC 3. oxidative phosphorylation
1. proton gradient needed for ATP synthesis can be stably established across a membrane that is _____ to ions - give 3 examples 2. this is most important for 3. membrane must contain proteins that couple the " " flow of ______ in the ETC with the " " flow of ____ across the membrane 4. The membrane must contain a protein that couples the "downhill" flow of protons to _________________________________.
1. impermeable - plasma membrane in mitochondria - inner membrane in mitochondria - thylakoid membrane in chloroplasts 2. oxidative phosphorylation- intact membranes 3. uphill flow of electrons downhill flow of protons 4. the phosphorylation of ADP
Which of the molecules is the major regulator of oxygen consumption during oxidative phosphorylation?
ADP High levels of ADP indicate high energy use (for example, in contracting muscle). As energy is used, the ADP concentration rises as the ATP concentration decreases. Regulation of the rate of oxidative phosphorylation by ADP concentration is called acceptor control.
ATP synthase converts the energy of the proton gradient into
ATP
the only gate for H+ to go back in mitochond. and generates ATP?
ATP synthase
Select the true statements about the electron transport chain. Coenzyme Q and cytochrome 𝑐c are components of the electron transport chain. The electron transport chain produces two ATP. The major reactants in the electron transport chain are O2 and either NADH or FADH2. In the electron transport chain, a series of reactions moves electrons through carriers. The electron transport chain is an anaerobic process.
Coenzyme Q and cytochrome 𝑐c are components of the electron transport chain The major reactants in the electron transport chain are O2O2 and either NADH or FADH2. In the electron transport chain, a series of reactions moves electrons through carriers.
actively transporting protons across the membrane
Complex I and Complex IV
complex of ETC
Complex I, III, and IV each participate in electron flow and the movement of protons from the mitochondrial matrix into the intermembrane space. These three complexes are the proton pumps of the electron transport chain - Complex I transfers two electrons from NADH to Q, using the energy of the transfer to pump four protons out of the matrix. Like complex II, complex I is an entry point to the electron transport chain. However, complex I is also a proton pump - Complex III transfers two electrons from QH2 to cytochrome 𝑐c and moves four protons out of the matrix. - complex 4 transfers 2 electron to oxygen and pumps two protons out of the matrix
which complex is not a proton pump *does not pump protons across the inner mitochondrial membrane
Complex II Succinate-Q reductase
complex 2
Complex II is a mitochondrial membrane‑bound component of both the electron transport chain and the citric acid cycle. The electron carrier FADH2 transfers two electrons from the citric acid cycle to complex II. Next, complex II transfers the electrons to Q, reducing it to QH2.
respirasome
Complexes I, III, and IV associate with each other to form a supramolecular assembly called *The respirasome organizes the complexes, enabling the rapid transfer of electrons between the different components of the electron transport chain. This organization allows more efficient proton pumping to the intermembrane space.
Cytochromes are critical participants in the electron transport chains used in photosynthesis and cellular respiration. How do cytochromes donate and accept electrons? Every cytochrome's iron‑containing heme group accepts electrons from oxygen and donates the electrons to the next cytochrome in the chain. The cytochromes donate electrons excited by photons to other cytochromes that accept electrons as replacements for lost electrons. Cytochromes donate electrons directly to the energy‑carrier molecules NAD+NAD+ and FADFAD and accept electrons from less electronegative substances. Each cytochrome has an iron‑containing heme group that accepts electrons and then donates the electrons to a more electronegative substance.
Each cytochrome has an iron‑containing heme group that accepts electrons and then donates the electrons to a more electronegative substance.
Electron transport sets up a proton-motive force
Energy of proton-motive force drives synthesis of ATP.
Which compounds are the final products of the electron transport chain and oxidative phosphorylation?
FAD NAD+ ATP H20
Which compounds donate electrons to the electron transport chain?
FADH2 NADH
what has the ability to accept or donate electrons
Fe- so all are Fe containing proton pumps
ATP synthase allows ___ to go back into matrix uses _____ energy of gradient to force protons into _____, make high energy bonds and make ___
H+ *use potential energy of gradient to force protons into ADP, make high energy bonds and make ATP
function ETC
H+ gradient
What is the advantage of having Complexes I, III, and IV associated with one another in the form of a respirasome? It facilitates the energetically unfavorable electron transfer reactions carried out by Complexes I, III, and IV. The respirasome allows NADHNADH and FADH2FADH2 to interact directly with the inner mitochondrial membrane. It enables the rapid transfer of electrons, thereby increasing the efficiency of proton pumping. A respirasome composed of Complexes I, III, and IV allows the efficient transfer of electrons from FADH2FADH2 to oxygen.
It enables the rapid transfer of electrons, thereby increasing the efficiency of proton pumping.
What is the function of the proton gradient in the mitochondrion?
It is potential energy that the cell uses to generate ATP. The electron transport chain connects the transfer of electrons between electron carriers with the movement of protons across the inner mitochondrial membrane. The proton gradient is potential energy that can power ATP synthesis. NADHNADH and FADH2FADH2 deliver electrons to protein complexes of the electron transport chain. The protein complexes of the electron transport chain transfer electrons down the chain, and this electron flow enables protons (H+)(H+) to be pumped into the mitochondrial matrix, which is the interior of the mitochondria.
What is the function of cytochrome c in the electron transport chain? It transports two electrons from NADH or FADH2 to complex III. It oxidizes FADH2 to FAD. It oxidizes NADH to NAD+. It reduces two molecules of Q to QH2. It transports an electron from complex III to complex IV.
It transports an electron from complex III to complex IV. Cytochrome c, a water‑soluble protein, moves electrons from complex III to complex IV. Complex III, also called the Q‑cytochrome c oxidoreductase complex, reduces cytochrome c using an electron from QH2. Complex IV, also called cytochrome c oxidase, oxidizes cytochrome c by transferring the electron to molecular oxygen. The transfer of electrons by complex III and complex IV is linked to the movement of protons out of the matrix. The other special electron carrier of the chain, Q, transfers electrons from NADH or FADH2 to cytochrome c at complex III. The reduced form, QH2, donates one electron at a time to cytochrome c at complex III. Thus, cytochrome c is the agent for the oxidation of QH2 to Q. Complex I oxidizes NADH to NAD+ and reduces Q to QH2. Complex II reduces Q to QH2 using electrons from the oxidation of FADH2 to FAD
major products of cac WHERE DO THEY GO
NADH FADH2 go in oxidative phosphorylation electron carriers- transfer to o2 but not directly bc need to get energy from them
what gives electrons to ETC
NADH , FADH2
respiratory chain transfers electrons from ____ and _____ to ________ and simultaneously generates a ____ _______
NADH AND FADH2 oxygen proton gradient
electrons flow down an energy gradient from what to what this flow is catalyzed by ?
NADH TO O2 by four protein complexes
Complex I transfers electrons from _____ to ______. Complex II transfers electrons from _____ to _________. Complex III transfers electrons from ubiquinone to cytochrome c, and Complex IV transfers electrons from cytochrome c to oxygen. Complexes I, III, and IV are proton pumps that use the energy released from electron transfer reactions to move protons into the intermembrane space.
NADH to ubiquinone FADH2 to ubiquinone
steps of ETC ____ transfers what to ______ _____ transfers ___ to complex _ ___________ accepts _ electrons, can release _ bc complex _ accepts _ electron(s) ________ transfers _ electron(S) to ________ this then transfers electron to -->which then transfers electron to--> last ?
NADH transfers 2 e- to complex 1 FADH 2 transfers 2 e- to complex 2 Ubiquinone accepts 2 electrons, can release 1 bc complex 3 accepts 1 electron(s) Ubiquinone transfers 1 electron to complex 3/ Q-cytochrome c oxidoreductase --> transfers electron to Cytochrome C--> transfers to complex 4--> transfers to O2 making water
complex 1 is called
NADH-Q oxidoreductase
proton gradient is formed using the energy released by _____ ____ protons are moved _____ the _______ ________ using the energy released by ____ _______
electron transport against, electrochemical gradient, electron transport
Which compound is the final electron acceptor?
O2
what maintains H+ gradient
O2- final e- acceptor + H atom 2H+ used from matrix - subtract even protons from matrix
NOTES FROM HOMEWORK
Oxidation is the loss of electrons. The reduced coenzymes NADH and FADH2 are oxidized to NAD+ and FAD, donating electrons and hydrogen in the electron transport chain in a series of exothermic reactions. The energy from these reactions is used to generate ATPATP via oxidative phosphorylation in a reaction with the hydrogen phosphate ion. ADP+HOPO2−3⟶ATP+H2OADP+HOPO32−⟶ATP+H2O The electrons from NADHNADH and FADH2FADH2 are passed from one oxidizing agent to another in the electron transport chain. In the last step, electrons are passed to oxygen, which combines with hydrogen to form water. O2+4e−+4H+⟶2H2OO2+4e−+4H+⟶2H2O Therefore, the final products are NAD+, FAD, H2O, and ATP.
electron transport chian energy of transferring ___ also moves ___ through membrane this does what
electrons, H+ increases H+ concentration in inner membrane mitochondria
The electron transport chain (ETC), or respiratory chain, is linked to proton movement and ATPATP synthesis Select the statements that accurately describe the electron transport chain. Prosthetic groups, such as iron-sulfur centers, are directly involved with electron transfer. The outer membrane of mitochondria is readily permeable to small molecules and hydrogen ions. Electron carriers are organized into four complexes of proteins and prosthetic groups. Electrons generated by the citric acid cycle in the intermembrane space enter the ETC. Electron carriers in the ETC include ubiquinone (coenzyme Q) and cytochrome c. Electron transfer in the ETC is coupled to proton transfer from the matrix to the intermembrane space. The reactions of the ETC take place in the outer membrane of mitochondria.
Prosthetic groups, such as iron-sulfur centers, are directly involved with electron transfer. The outer membrane of mitochondria is readily permeable to small molecules and hydrogen ions. Electron carriers are organized into four complexes of proteins and prosthetic groups. Electron carriers in the ETC include ubiquinone (coenzyme Q) and cytochrome c. Electron transfer in the ETC is coupled to proton transfer from the matrix to the intermembrane space.
complex 3 is called
Q-cytochrome c oxidoreductase
complex 2
Succinate-Q reductase
true or false ATP synthase uses energy from ATP to move H+ into the mitochondrial matrix
The H+H+ concentration gradient is a potential energy source. Because the H+H+ concentration is higher in the intermembrane space, H+H+ can diffuse across the inner mitochondrial membrane through a channel that is part of the ATPATP synthase enzyme complex. The energy released by the flow of H+H+ into the mitochondrial matrix drives the formation of ATPATP from ADPADP .
complex 4 is called
cytochrome c oxidase
glycolysis occurs in the
cytoplasm
electrons enter the ETC through
either complex 1 or 2
notes from homework
The electron transfer reactions carried out by Complexes I - IV are energetically favorable. The complexes are arranged in a way that allows electrons to flow to compounds with higher electron affinity. Since oxygen has the highest electron affinity, electron flow through the electron transport chain is energetically favorable. The energy released from electron transfer is used to pump protons from the matrix into the intermembrane space. Complex I, which is part of the respirasome, does not transfer electrons from FADH2.FADH2. Instead, complex II, which is not part of the respirasome, transfers electrons from FADH2FADH2 to ubiquinone. Electrons are transferred from ubiquinone to oxygen in the same manner as the electrons from NADH The respirasome does not allow NADHNADH and FADH2FADH2 to interact directly with the inner mitochondrial membrane. NADHNADH and FADH2FADH2 are water‑soluble electron carriers that do not directly associate with lipid membranes. Instead, both electron carriers interact with proteins that can interact with the inner mitochondrial membrane
What is the proton gradient in cellular respiration? a higher concentration of protons (H+)(H+) on one side of a membrane than the other the accumulation of ATPATP on one side of the inner mitochondrial membrane the movement of protons (H+)(H+) across a selectively permeable (semipermeable) membrane the passive transport of electrons across the inner mitochondrial membrane
a higher concentration of protons (H+)(H+) on one side of a membrane than the other A proton gradient is the difference in the concentration of protons (H+) across a membrane. In mitochondria, the proton gradient is set up by the electron transport chain and results in a higher concentration of protons in the space between the inner and outer mitochondrial membranes and a lower concentration of protons inside the mitochondrial matrix.
Which processes yield the most ATP ? When determining the ATP yield for each process, include ATP derived from reduced cofactors.
citric acid cycle
1st carbon of pyruvate lost where
co2 in making of acetyl co-A
protons are pumped from ____ to inner membrane spacing generating
matrix H+ gradient charge inside mitochondria - outside +
Where is the citric acid cycle located?
mitochondrial matrix
where is place for CAC in body
mitochondrial matrix
where is place for pyruvate decarboxylation in cell?
mitochondrial matrix
atp synthase is a
molecular motor
matrix is _____ charged
negatively
do electrons travel alone
no, protons travel nearby molecules grab electrons and proton and transfer to protein in chain, H+ released from first molecule onto opposite side of membrane
what are coupled by transmembrane proton fluxes
oxidation atp synthesis
releasing protons into the intermembrane space
oxidation of QH 2
major way atp produced in body
oxidative phosphorylation
oxidized and reduced versions NADH AND FADH2 NADH is formed when NAD+ accepts electrons during the breakdown of glucose during glycolysis. Additional NADH is formed by the citric acid cycle. FADH2 is formed when FAD accepts electrons in the citric acid cycle
oxidized: FAD and NAD+ (oxidized forms that do not carry electrons) reduced: NADH, FADH2 (electron‑carrying, forms of the molecules that deliver electrons to the electron transport chain)
2 things for oxidative phosphorylation
proteins- ETC atp synthase
inner membrane is impermeable for this causes more
protons much more on one side- gradient
complexes pump what out of what, generating what
protons out of matrix generate proton gradient
inner membrane has huge this causes
surface area more protein factories- more atp made
ADP +P =ATP is highly
thermodynamically unfavorable
Which process will be immediately inhibited if cytochrome c is unable to interact with cytochrome c oxidase? transfer of electrons to H2OH2O transfer of electrons from cytochrome c to O2O2 transfer of electrons from coenzyme Q to cytrochrome c transfer of electrons from cytochrome c to coenzyme Q
transfer of electrons from cytochrome c to O2O2 Cytochrome c is a mobile electron carrier in the respiratory chain. Complex III transfers electrons from Coenzyme Q to cytochrome c. Cytochrome c oxidase, also known as Complex IV, transfers electrons from cytochrome c to oxygen. Oxygen is the final electron acceptor in aerobic respiration, and is reduced to water in this process.
