Biochemexam3 Lecture 20

Front 1

Which of the following is false regarding the mitochondrial inner membrane:
a) made up of 80% protein
b) rich in unsat. fa's
c) where enzymes involved in transfer of E are involved.
d) contains porphorin and cardiolipin

Back 1

c) where enzymes involved in transfer of E are involved.
(intermembrane space)

Front 2

The matrix contains all of the enzymes for the TCA cycle except 4 of them. These 4 include the following except:
a) succinate dehydrogenase bound to inner membrane
b) enzymes for FA oxidation
c) enzymes for urea synthesis
d) enzymes for porphorin synthesis
e) enzymes for amino acid hydrolysis

Back 2

e) enzymes for amino acid hydrolysis

Front 3

An electron donor is called a __a______.

An electron acceptor is called a _____b______.

Back 3

a) reductant

b) oxidant

Front 4

What's the transfer of electrons from one chemical species to another called?

Back 4

redox rxn

Front 5

What's is called when you have the oxidized plus reduced form of each chemical species?

Back 5

electrochemical half cell

Front 6

What comprises a redox rxn?

Back 6

2 half cells with one common intermediate

Front 7

T/F? Coupled half cell rxns cannot drive energetically unfavored rxns in the same way that thermodynamically coupled rxns do.

Back 7

false (they can!)

Front 8

Redox potential can be determined by measuring the ____a____ ___a___ generated by half-cell with respect to a standard reference half-cell.

Negative redox potential means the cmpd had __b___ e- affinity than H2, and positive redox has ____c____ e- affinity than H2.

Back 8

a) electromotive force

b) lower

c) higher

Front 9

Regarding redox potential, _a___ is a strong reducing agent, whereas __b__ is a strong oxidizing agent.

Back 9

a) NADH

b) O2

Front 10

The oxidation reduction potential can be determined using ____________.

Back 10

the Nernst equation

Front 11

The only factor we really like to look at in the Nernst equation is ___.

Back 11

n=number of transferred electrons because as they INCREASE, we get more energy.
(NADH-->transfer 2e-)

Front 12

Direct chemical analysis shows that for every 2 electrons transferred from NADH to oxygen, _a__ equivalents of ATP are synthesized, and __b__ for FADH2.

Back 12

a) 2.5

b) 1.5

Front 13

Complex I involves:
a) NADH dehydrogenase, FMN, and Fe-S centers
b) succinate dehydrogenase, FAD, Fe-S centers, b-type heme
c) cytochrome bc1 complex, 2 b-type hemes, Rieske Fe-S centers, and c-type heme
d) cytochrome aa3 complex, 2 a-type hemes, Cu ions.

Back 13

a) Complex I
b) Complex II
c) Complex III
d Complex IV

Front 14

Which complex involves the catalyzed xfer of alcohols from ubiquinone to cytochrome C

Back 14

complex III

Front 15

In Complex I, there's an overall oxidation of NADH and transfer of _a__ electrons to ____b_____.

This all occurs btwn the __c___ and ____d____.

You get _e_ protons out of it.

Begins with xfer of 2e- to __f__.

Back 15

a) 2
b) ubiquinone (coenzyme Q)

c) matrix
d) intermembrane space

e) 4 protons
f) FMN

Front 16

Ubiquinone can accept and transfer one and two electrons due to the ___________.

Back 16

semiquinone

Front 17

________ ________ makes CoQ lipid soluble for shuttling e- btwn complexes __ and __.

Back 17

hydrophobic isoprene

I and II

Front 18

The reduction of ubiquinone includes all ____a____ ____a_____ including what?

Back 18

a) flavoprotein dehydrogenases

includes:
-Complex I and II (succinate DH)
-glycerol-3-Pi DH
-electron transferring flavoprotein-ubiquinone oxidoreductase

Front 19

T/F? Complex II contains succinate dehydrogenase and is primarly composed of 2 subunits: 1) 70kD of FAD covalently bound to histadine and 2) 30kD of 3 Fe-S centers and 2 relatively small/hydrophobic proteins

Back 19

true

Front 20

What does the membrane anchoring domain on Complex III contain?

Back 20

heme + Fe-S protein

Front 21

T/F? Complex I has cytochrome C oxidoreductase.

Back 21

false.
(complex III has this!)
Complex I has NADH-Ubiquinone Oxidoreductase

Front 22

The transmembrane domain of complex III contains what?

Back 22

2 heme + Fe-S protein

Front 23

T/F? Complex III transfers e- to cytochrome C and e- goes across membrane.

Back 23

true

Front 24

T/F? Hemes in cytochromes are structurally similar to Hb heme--however unlike Hb, they undergo oxidation-reduction (Fe2-->Fe3)

Back 24

true

Front 25

Regarding the transfer of e- from CoQ to Complex III, which of the following is false:
a) Cytochrome B contains 2 heme groups (a high potential and a low potential heme)
b) cytochrome c contains 3 type of c-hemes
c) 2 protons are taken up on the matric side of the inner membrane to reduce the ubiquinone
d) 4 protons are released on the cytosolic side of the membrane during the transfer of 2e- to the Fe-S proteins and cytochrome c1.

Back 25

b) b) cytochrome c contains 3 type of c-hemes

Front 26

Regarding transfer of e- from CoQ to Complex III, 4 protons are released on the ____a_____ of the membrane during the transfer of 2e- to the ______B_____ and ____c_____.

Back 26

a) cytosolic side
b) Fe-S proteins
c) cytochrome c1

Front 27

The Q-cycle mechanism accounts for the transfer of __a___ across per __b___ transferred from ___c____ to _______d____.

Back 27

a) 4 protons

b) 2 electrons

c) ubiquinol

d) cytochrome c

Front 28

In the transfer of e- from CoQ to Complex III, 2 protons are taken up on the _____ side of the inner membrane to reduce the ubiquinone.

Back 28

matrix side

Front 29

T/F? Each complex is dependent on each other.

Back 29

false
(they each exist independently)

Front 30

Antibx inhibit complex _a_.

Sedatives inhibits complex _b_.

CO and cyanides inhibit complex _c_.

Back 30

a) III

b) I

c) IV