19.1 Oxidative Phosphorylation 731-747 Flashcards Preview

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Flashcards in 19.1 Oxidative Phosphorylation 731-747 Deck (17)

Q # 2 Why does it make physiological sense that heart mitochondria have more sets of electron transfer components than liver mitochondria?

The heart is a muscle producing contractions constitutively, while the liver is a less motile organ.


Q # 3 How does the structure of the mitochondrion provide for physical separation of metabolic processes in the cell?

The selectively permeable inner membrane segregates the intermediates and enzymes of cytosolic metabolic pathways from those of metabolic processes occurring in the matrix.


Q # 5 what is the cellular role of NADH? NADPH?

water soluble electron carriers that associate reversibly with dehydrogenases, and give their electrons up to the electron transport chain.


Can NADH or NADPH cross the inner mitochondrial membrane?

No, but their electrons can be shuttled independently.


Reduction potential

The relative tendency of a given chemical species to accept electrons in an oxidation-reduction reaction


Q # 7 Which chemical characteristics of ubiquinone make it uniquely useful in the electron transfer chain?

Ubiquinone is small and hydrophobic making it freely diffusible within the lipid bilayer of the inner mitochondrial membrane and can shuttle reducing equivalents between other less mobile electron carriers in the membrane.


Reducing equivalent

a single electron equivalent transferred in an oxidation-reduction reaction.



Co-enzyme Q; a lipid-soluble benzoquinone with a long isoprenoid side chain; responsible for carrying electrons in membrane-associated electron transfer chains


How many H+ and e- does NADH carry?

1 H+ and 2 e-


How many H+ and e- does FADH2 carry?

1 or 2 H+ and e-


How many H+ and e- does Ubiquinone carry?

1 or 2 H+ and e-


How many H+ and e- do Iron sulfur groups carry?

iron sulfur groups can only carry 1 e- and no protons.


How many H+ and e- do cytochrome carry?

carry 1 e- only


What electron carrier acts as a prosthetic group?

FADH2 is a prosthetic group.


How many electron carrying prothetic groups are generated from one glucose? Are they on the same enzyme?

4, No


What is the role of cytochrome c is electron transport?

Cytochrome C is a soluble of electrons; it carries electrons between complexes III and IV.


If we purified mitochondrial membranes, could we make the electron transport chain work in a test tube?

No; cytochrome C wouldn't be present, because it is hydrophillic and soluble.

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