Lecture 29 - Ox-Phos Intro Flashcards
The ____ is the location of both the TCA cycle and fatty-acid oxidation.
A. Matrix
B. intermembrane space
C. Inner membrane
A. matrix
Oxidative phosphorylation occurs in the _____.
inner mitochondrial membrane
A patient lacks the ability to generate NADH and FADH2 molecules. What would this condition do to the patient’s ability to produce ATP?
A. No change
B. Decrease ATP production
C. Increase ATP production
D. Change the primary mechanism of ATP production to anaerobic metabolism
B. Decrease ATP production; a vast majority of human ATP production arises from oxidative phosphorylation, which requires the production of high energy electron carriers FADH2 and NADH. The ETC is unable to function w/o FADH and NADH2
Electrons are ultimately added to \_\_\_\_ at the end of the ETC. A. Water B. ATP synthase C. Oxygen D. Cytochrome c
C. Oxygen (added to oxygen to produce water)
Trace the flow of electrons from NADH to oxygen.
NADH Q oxidoreductase (Complex I)
Ubiquinone
Q cytochrome c oxidoreductase (Complex III)
Cytochrome c oxidase (Complex IV)
Trace the flow of electrons from FADH2
Succinate Q reductase (Complex II) Ubiquinone Q cytochrome c oxidoreductase (Complex III) Cytochrome C Cytochrome c oxidase (Complex IV)
Why are electrons easily passed between the various components of the ETC?
Each subsequent component (Complex I - Complex IV) is more electronegative the prior. This “pulls” the electrons, and allows them to “lose E*” to pump H+.
Prosthetic group of NADH-Q oxidoreductase
FMN
Fe-S
Prosthetic group of succinate-Q reductase
FAD
Fe-S
Prosthetic group of Q-cytochrome c oxidoreductase.
Heme bH
Heme bL
Heme C1
Fe-S
Prosthetic group of cytochrome c oxidase
Heme a
Heme a3
CuA and CuB
Coenzyme Q may exist in several forms. The fully oxidized form is known as \_\_\_\_\_\_. A. Ubiquinone B. Ubiquinol C. Semiquinone radical D. Semiquinone intermediate
A. Ubiquinone
The fully reduced form of Coenzyme Q is known as \_\_\_\_\_\_. A. Ubiquinone B. Ubiquinol C. Semiquinone radical D. Semiquinone intermediate
B. Ubiquonol
These are highly important in the oxidation-reduction reactions of the ETC.
Fe-S clusters
Friedereich’s ataxia results in trinucleotide repeats of the gene for frataxin. This produces a decrease in mitochondrial protein frataxin. What is the immediate result?
A. CNS/heart damage
B. Complete destruction of mitochondria, which makes Friedereich’s ataxia fatal
C. lack of Fe-S clusters required for ETC function
D. Blindness at an early age
C. lack of Fe-S clusters required for ETC function
The mitochondria consists of two membranes. The outer membrane is permeable to (-) ions via the _____.
A. metabolite transporters
B. VDAC
C. Malate shuttle
B. VDAC (Voltage dependent anion channel)
Which of the ETC complexes does NOT pump electrons?
Complex II (Succinate Q reductase)
This complex utilizes FMN and Fe-S clusters to move electrons. The moved electrons induce changes to the transmembrane proteins and allow for H+ to be pumped into the intermembrane space.
Complex I (NADH-Q oxidoreductase)
Flavin mononucleotide exists in what chemical formula when fully reduced?
A. FMN
B. FMNH
C. FMNH2
C. FMNH2
Complex I pumps ____ into the cytoplasm.
4 H+
Complex II binds _____ and transfers the electrons to the _____.
FADH2; Q pool to form QH2
Complex III passes electrons from ___ to ___. Complex III is known as ______
QH2; cyctocrhome C; cytochrome C reductase
Complex III (Q-cytochrome C oxidoreductase) contans what specialized Fe-S centers?
Rieske Iron-Sulfur Centers; these utilize Cys and His residues
How is ubiquinone regenerated in the Q cycle?
After the first 1/2 of the Q cycle, a semiquinone (Qe-) is produced. When another QH2 passes its electrons off, another e- is added to semiquinone, forming ubiquinol (Q 2e-). Two H+ atoms are bound to the ubiquinol, which regenerates QH2, and it is “recycled.”
What are the final products of the reaction of Complex III (cytochrome c oxidoreductase)
2 QH2 oxidized to Q
4 H+ atoms (pumped out)
2 reduced cytochrome c molecules formed
Complex IV (cytochrome c oxidase) produces what product?
water
