Quiz 228 Flashcards
Mitochondria store energy as electricity by creating an __________________ across the inner ___________________ (potential energy). Ionic gradients are used to synthesize ATP, which is driven by the energy that’s released from ___________________, a process called ___________________. Substrate level phosphorylation happens when____________ is added to _______________ . Ox phos makes a stupid amount of ATP every day.
ionic gradient , mito membrane , electrons removed during substrate oxidation, oxidative phosphorylation, phosphate group, ADP
Complex 4- Cytochrome C oxidase.
Transfers e- to oxygen. Huge assembly of polypeptides.
O2 can be reduced to water because of
how many anions are produced during the process (?)
For every o2 reduced to h2o by cytochrome oxidase, ___ protons are consumed and ___ are moved across inner mito membrane. First ___ are substrate, latter ___ are pumped. Moving any proton contributes to _______________
- 4, 4, 4, electrochemical gradient
ATPase- uses energy obtained from ATP hydrolysis to _________________-. Can _______________ under certain circumstances, which normally aren’t present in the body.
export Na+ and import K+ against gradient, catalyze formation of ATP
Complex 1- Gateway to _________________, which transfers e- from _______ to _________ to make ____________-.
e- transport chain, NADH, ubiquitone, uniquinol
complex 2 (Succinate dehydrogenase)-
Creates pathway for feeding low evergy electrons from succinate to FAD to ubiquinone.
Complex 3 (Cytochrome bc1)-
Catalyzes e- transfer from ubiquinol to cytochrome c. Releases protons into intermembrane space. Subunits of complex 3 contain redox groups- cytochrome b has 2 heme b molecules with different redox potentials, cytochrome c1, and iron sylfur protein
Movement of electrons creates ____________ of charge, so electron affinity of substances is measured by ______________
separation, voltage
Chain of redox agents progressively ____________ until they get to _____, which accepts energy-less electrons and reduces it to _____. Rate of transfer between carriers depends on _____________ involved
releases energy, O2, H2O, catalytic activities of proteins
4 complexes in ETC + 2 cother components, cytochrome c (_______________________) and ubitquinone (_______________________).
soluble protein in intermembrane space, pool of molecules in lipid bilayer
F1 sphere-
catalytic portion of ATP manufacturing enzyme.
ATP synthesizing enzyme-
ATP synthase with F1 head and Fo, basal unit with toxin bound to it.
When NADH is e- dono in ETC, e- enter resp chain via complex _____, which transfers e- to _______________, making _______________. ________ can move away from soluble dehydrogenases, but _____ binds to it (and complex 2 as a whole).
1, transfers e- to ubiquinone, ubiquinol, NADH, FASH2
__________ serving as e- donor means that e- are passed to ________, not going through complex one because it’s too negative to take less energetic electrons like those present in flavin nucleotide.
FADH2, ubiquinone
Sites where release of energy occurs (coupling sites) happen between carriers part of complexes ____________. Free energy is released as _________ that are passed through the chain, which is saved by ______________________ of______________________. They move through channels by switching places with other protons present in the pathway, creating a proton gradient that drives ____________.
1, 3, and 4, electrons, protons moving across the matrix, inner membrane to intermembrane space through proton pumps, ATP synthesis
Energy released by movement of protons is used to change the ____________________________ for the ATP product. Each active site progresses through 3 conformations with different affinities for substrates and products, but all ATP is produced by an enzyme made by same mechanism. All catalytic sites of enzyme operate identically. ATP is synthesized by rotational catalysis where one part of ATP synthase rotates relative to another part.
binding affinity of the active site
As gamma uit rotates, each binding site interacts with f1 subunits of atp in different conformations, Forms ATP from ADP and Pi
What is the path taken by protons as they move through the Fo complex, and how does this movement lead to the synthesis of ATP?
The c subunits of the Fo base were assembled into a ring that resides within the lipid bilayer
The c ring is physically bound to the γ subunit of the stalk.
The “downhill” movement of protons through the membrane drives the rotation of the ring of c subunits.
The rotation of the c ring of Fo provides the twisting force (torque) that drives the rotation of the attached γ subunit, leading to the synthesis and release of ATP by catalytic subunits of the F1 ring.
The mechanism by which H+ movements drive the rotation of the c ring is summarized by the model shown in Figure 5.30. Keep in mind in the following discussion of this model that (1) the subunits of the c ring move successively past a stationary a subunit and (2) protons are picked up from the intermembrane space one at a time by each c subunit and carried completely around a circle before they are released into the matrix.
