Class 2: OX Phos I

Question 1

Mitochondria membrane systems:

Answer 1

Outer membrane: permeable d.t porin VDAC

Inner membrane: impermeable, folded in cristae.

Question 2

2 compartments of the mito. :

Answer 2

Intermembrane space

Matrix: TCA and FA oxidation

Question 3

WHere does ox phos occur?

Answer 3

Inner membrane of mito.

Question 4

Semi-autonomous organelles.
HAVE THEIR OWN DNA, MAKE PROTEINS AND RNAs.
All mito. Derived from rickettsia prowazekii by endosymbiotic event.
Human DNA has 16,569 bp and encodes 13 respiratory chain proteins, rRNAs, tRNAs.

Answer 4

Mitochondrial genome.

Question 5

TCA cycle generates :

Answer 5

Electron carriers. NADH and FADH2

Question 6

Electrons reduce->

Answer 6

O2 to water

Question 7

Which 3 complexes pump H+ into the intermembrane space?

Answer 7

1,3, and 4

Question 8

How do H+s return to the matrix from intermembrane space?

Answer 8

ATP synthase - powers synthesis of ATP

Question 9

NADH Q oxidoreductase

Answer 9

Complex 1

Question 10

Succinct Q reductase

Answer 10

Complex 2

Question 11

Q cytochrome c oxidoreductase

Answer 11

Complex 3

Question 12

Cytochrome c oxidase

Answer 12

Complex 4

Question 13

Electron flow is ________

Answer 13

Exergonic

Question 14

Succincte Q reductase generates FADH2 and has what enzyme from TCA in it?

Answer 14

Succinate dehydrogenase

Question 15

Which complex doesnt pump electrons across membrane to intermembrane space?

Answer 15

Succinate Q reductase

Or

Complex 2

Question 16

Complex 1,3,4 collectively are called

Answer 16

Respirasome

Question 17

Transfers e- from NADH Q oxidoreductase and then succinate Q reductase to Q cytochrome c oxidoreductase

Answer 17

Coenzyme Q

Or

Ubiquinone

Question 18

Shuttles e- from Q cytochrome c oxidoreductase(3) to cytochrome c oxidase (4)

Final component of ETC

Catalyzes the reduction of O2

Answer 18

Cytochrome c

Question 19

Prosthetic groups for complex 1:

Answer 19

FMN

Fe-S

Question 20

Complex 2 prosthetic groups:

Answer 20

FAD

Fe-S

Question 21

Complex 3 prosthetic groups:

Answer 21

Heme b and c

Fe-S

Question 22

Complex 4 prosthetic groups:

Answer 22

heme a

Cu

Question 23

Play a role in reduction reactions.

Oxidation-reduction reactions but the H+’s never leave the protein.

Answer 23

Fe-S clusters

Question 24

Rare inherited RECESSIVE disease.
Caused by mutation in the protein FRATAXIN.
Issue: synthesis of Fe-S clusters.
Affects CNS, PNS, heart, and skeletal system –excitable cells.
Common mutation is trinucleotide expansion in fraxtaxin gene.

Answer 24

Friedreich’s ataxia

Question 25

First point of entry of electrons from NADH.

Pumps 4 protons into intermembrane space.

Answer 25

Complex 1

Question 26

FADH2 enters ETC and doesnt leave through:

Leave ATP synthesized from oxidation of FADH2

Answer 26

Complex 2

Question 27

Electrons from QH2 are passed on to cytochrome c by:

2 protons pumped into intermembrane space

Answer 27

Complex 3

Question 28

Solves problem of cyt c only carrying 1 e- from CoQ

Answer 28

Q cycle

Question 29

Catalyzes transfer of e-‘s from reduced cyt c to molecular O2, the final acceptor

Makes these reactions aerobic, makes ppl breath.

4 e-s funneled to O2 to reduce it to water

Answer 29

Complex 4

Question 30

4 protons are pumped and 4 protons are used to form 2 molecules of water :

Answer 30

Peroxide bridge

Question 31

Complete reduction of O2 forms water.
Partial reduction forms dangerous species.
Can form superoxide anion or hydrogen peroxide.

Hydroxyl radical formed from both

Answer 31

Free radicals

Question 32

Dz asso. W/ free radicals:

Answer 32

Parkinson’s Dz

Ischemia; reperfusion injury

Question 33

Enzymes for antioxidants:

Answer 33

1. Superoxide dismutase (SOD) uses selenium. To turn superoxide anion to H2O2
2. Catalase converted H2O2 to 2 molecules of water.

Question 34

This protein has been conserved throughout nearly all of evo.

Answer 34

Cytochrome c