7.5 The Electron Transport Chain and Oxidative Phosphorylation Flashcards Preview

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Flashcards in 7.5 The Electron Transport Chain and Oxidative Phosphorylation Deck (31)
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1
Q

the complete oxidation of glucose during the first three stages of cellular respiration results in the production of:

A

two kinds of reduced electron carriers: NADH and FADH2

2
Q

the energy in electron carriers is released in a series of:

A

redox reactions that occur as electrons pass through a chain of protein complexes in the inner mitochondrial membrane to the final electron acceptor, oxygen, which is reduced to water

3
Q

the passage of electrons is coupled to the transfer of protons across the inner mitochondrial membrane creating:

A

a concentration and charge gradient: this electrochemical gradient provides a source of potential energy that is used to drive the synthesis of ATP

4
Q

the inner mitochondrial membrane is:

A

selectively permeable (Protons can’t passively diffuse across, other molecules’ movement controlled by transporters and channels)

5
Q

what are the two components of a proton gradient?

A

chemical-difference in concentration, electrical-difference in charge =e electrochemical gradient

6
Q

the proton gradient is a source of:

A

potential energy

7
Q

ATP synthase

A

an enzyme that couples the movement of protons through the enzyme with the synthesis of ATP

8
Q

the gradient of protons provides a source of potential energy that is converted into:

A

chemical energy stored in ATP

9
Q

chemiosmotic hypothesis

A

the hypothesis that the gradient of protons across a membrane provides a source of potential energy that is converted into chemical energy stored in ATP

10
Q

where do electrons enter the electron transport chain?

A

at complex I (NADH) or complex II (FADH2)

11
Q

the transport of electrons in complex I, III, and IV is coupled with:

A

the transport of protons across the inner membrane, from the mitochondrial matrix to the intermembrane space

12
Q

within each protein complex of the electron transport chain, electrons are passed from:

A

electron donors to electron acceptors

13
Q

each electron donor and acceptor is a:

A

redox couple, consisting of an oxidized and a reduced form of a molecule

14
Q

the final reduction of oxygen to water is catalyzed by which complex?

A

complex IV

15
Q

coenzyme Q (CoQ) AKA ubiquinone (hydrophobic)

A

in respiration, a mobile electron acceptor that transports electrons from complies I and II to complex III in the electron transport chain and moves protons from the mitochondrial matrix to the intermembrane space

16
Q

once two electrons and two protons are transferred to CoQ, it forms:

A

CoQH2

17
Q

cytochrome c (hydrophilic)

A

the enzyme to which electrons are transferred in complex III of the electron transport chain

18
Q

once electrons are transferred from CoQH2 to cytochrome c, what happens to the protons?

A

they are released into the intermembrane space

19
Q

the electron transfer steps are associated with the release of energy as electrons are passed from the reduced electron carriers (NADH, FADH2) to the final electron acceptor O2

A

some of the energy is used to reduce the next carrier, some used to pump protons across the inner mitochondrial membrane

20
Q

the result of transfer of electrons being coupled with the pumping of protons is an:

A

accumulation of protons in the intermembrane space

21
Q

where are protons in higher concentration?

A

in the intermembrane space, low concentration in the mitochondrial matrix. protons can’t diffuse into matrix because membrane blocks it, the gradient stores potential energy

22
Q

the oxidation of the electron carriers NADH and FADH2 which formed during glycolysis, pyruvate oxidation, and the citric acid cycle leads to:

A

the generation of a proton electrochemical gradient (a source of potential energy) which is used to synthesize ATP

23
Q

the ATP synthase enzyme is composed of two distinct subunits called:

A

F0 and F1

24
Q

Fo forms the:

inner mitochondrial membrane

A

channel in the inner mitochondrial membrane through which protons flow, rotates as protons pass through

25
Q

F1 is the :

mitochondrial matrix

A

catalytic unit that synthesizes ATP, uses rotational energy of Fo to synthesize ATP

26
Q

proton flow through the Fo channel causes it to rotate, converting the energy of the proton gradient into:

A

mechanical rotational energy (kinetic energy), leads to the rotation of the F1 subunit in the mitochondrial matrix

27
Q

the rotation of the F1 subunit causes:

A

conformational changes that allow it to catalyze the synthesis of ATP from ADP and Pi, converting mechanical energy into the chemical energy of ATP

28
Q

what are sufficient components to produce ATP?

A

a membrane, proton gradient, and ATP synthase

29
Q

for each molecule of NADH that donates electrons, how many ATP are produced?

A

2.5 molecules

30
Q

for each molecule of FADH2 that donates electrons, how many ATP are produced?

A

1.5 molecules

31
Q

overall, the complete oxidation of glucose yields how many ATP?

A

32