oxidative phosphorylation

Question 1

mitochondria chacteristics

Answer 1

oval shaped

comparable to the size of bacterium

Question 2

outer membrane

Answer 2

permeable due to presence of porin aka VDAC (voltage dependent anion channel)

Question 3

inner membrane

Answer 3

impermeable, has metobolite transporters, folded into cristae

Question 4

2 compartments of mitochondria

Answer 4

intermembrane space

matrix (site of TCA cycle and fatty acid oxidation)

Question 5

where does ox phos occur

Answer 5

inner membrane

Question 6

mitochondria has a _______ relationship with host cells

Answer 6

endosymboitic

Question 7

sequence data shows all mitochondria is derived from rickettsia prowazekii due to a

Answer 7

single endosymbiotic event

Question 8

human mitochondrial DNA has 16,569 base pairs and encodes ______ respiratory chain proteins, rRNAs, and tRNAs

Answer 8

13

Question 9

human mitochondrial DNA is _______ inherited

Answer 9

maternally

Question 10

TCA cycle generates

Answer 10

NADH and FADH₂

Question 11

in OxPhos, high energy electrons (from NADH and FADH₂) flow through

Answer 11

4 protien complexes called the electron transfer chain (ETC)

Question 12

electrons reduce

Answer 12

molecular O₂ to water

Question 13

which complexes pump protons from matrix to intermembrane space

Answer 13

complexes I, III, and IV

Question 14

protons (that have been pumped into intermembrane space) return to matrix by flowing through complex called

Answer 14

ATP synthase

Question 15

a successful OxPhos must accomplish these goals:

1.

2.

3.

Answer 15

1. transfer of electrons from NADH and FADH₂ → O₂
2. establish a proton gradient across the inner mitochondrial membrane
3. synthesize ATP

Question 16

electrons are transferred from NADH to O₂ via which complexes

Answer 16

complex I: NADH-Q oxidoreductase (NADH dehydrogenase)

complex III: Q-cytochrome C oxidoreductase

complex IV: cytochrome c oxidase

Question 17

electron flow is endergonic or exergonic

Answer 17

exergonic (releases energy) that powers flow of protons across inner membrane

Question 18

name of complex II

Answer 18

succinate Q reductase

Question 19

complex II (succinate Q reductase) has what enzyme?

Answer 19

succinate dehydrogenase which generates FADH₂ in TCA cycle

Question 20

electrons from FADH₂ enter ETC through

Answer 20

complex II (succinate Q reductase)

Question 21

coenzyme Q (ubiquinone)

Answer 21

transfers electrons from NADH Q oxidoreductase and the succinate Q reductase to Q cytochrome c oxidoreductase

has a long tail make of 5 - C isoprene units which make it hydrophobic

most common is CoQ 10

Question 22

respirasome

Answer 22

complex I, III, and IV because they produce protons

Question 23

cytochrome c

Answer 23

shuttles electrons from Q cytochrome c oxidoreductase to cytochrome c oxidase

final component of the ETC

catalyzes reduction of O₂

Question 24

what is the largest complex of ETC

Answer 24

NADH-Q oxidoreductase (complex I) (NADH dehydrogenase)

Question 25

complex I is encoded by

Answer 25

both nuclear and mitochondrial genes

Question 26

first entry point of electrons from NADH

Answer 26

complex I

Question 27

reaction catalyzed by complex I

Answer 27

NADH + Q + 5H⁺ _matrix → NAD⁺ + QH₂ + 4H⁺_cytoplasm

Question 28

iron sulfer clusters

Answer 28

undergo oxidation-reduction reactions but the protons ???????? never leave the protein

Question 29

which complex connects TCA to OxPhos

Answer 29

succinate-Q reductase (complex II)

Question 30

in complex II, FADH₂ does not leave the complex, its electrons are transferred

Answer 30

to FeS and then to Q to form QH₂

Question 31

less ATP is synthesized from

Answer 31

oxidation of FADH₂

Question 32

reaction in complex III

Answer 32

electrons from QH₂ (or CoQ) are passed on to cytochrome c by cytochrome c oxidoreductase (complx III)

flow of electrons through this complex leads to transport of 2 protons to cytoplasmic side

Question 33

complex IV (cytochrome c oxidase)

Answer 33

catalyzes transfer of electrons from reduced cytochrome c to molecular oxygen (FINAL ACCEPTOR)

makes these reactions aerobic

makes humans “breathe”

four electrons funneled to oxygen to reduce it to water

at the same time, protons are pumped from matrix to cytoplasmic side of inner membrane

Question 34

cytochrome c oxidase consists of

Answer 34

2 heme and 3 Cu groups

Question 35

partical reduction of O₂ generates

Answer 35

highly reactive oxygen derivatives, called reactive oxygen species (ROS)

Question 36

what is the major free radical generator

Answer 36

mitochondria

Question 37

reactive oxygen species (ROS) includes

Answer 37

superoxide ion, peroxide ion, and hydroxyl radical

Question 38

normal amounts of RNS and ROS are used for

Answer 38

physiological signaling (for growth, hormone synthesis, and inflammation)

Question 39

overproduction of RNS and ROS

Answer 39

damage from oxidation of DNA, proteins, and lipids

Question 40

antioxidants:

superoxide dismutase (SOD):

catalase:

Answer 40

SOD: catalyzes superoxide ion + 2H+ → O₂ + H₂O₂

catalase: catalyzes 2H₂O₂ → O₂ + 2H₂O

Question 41

examples of antioxidants

Answer 41

glutathione peroxidase

Vit-E

Vit-C

Question 42

superoxide dismutase:

Cu/Zn SOD (SOD1) is found:

Mn/Zn SOD (SOD2) is found:

Answer 42

cytosolic

mitochondrial