ETC

Question 0

T or F: ETC can only occur in cells with mitochondria

Answer 0

T

Question 1

Name the 4 complexes

Answer 1

Complex I (NADH dehydrogenase), Complex II (Succinate Dehydrogenase), Complex III (Ubiquinone-Cytochrome C oxidoreductae), Complex IV (Cytochrome oxidase)

Question 2

Which membrane of the mitochondria is more permeable?

Answer 2

Outer membrane. Inner membrane is much more tightly regulated

Question 3

Where does NADH feed into the ETC?

Answer 3

Complex I (NADH dehydrogenase)

Question 4

Where does FADH2 feed into the ETC?

Answer 4

Complex II (Succinate dehydrogenase)

Question 5

Trace an electron from NADH2 through the ETC

Answer 5

Complex I to Complex III via Ubiquinone to Cytochrome C to Complex IV, to Oxygen

Question 6

What is the redox potential? how does it relate to ETC?

Answer 6

The more negative the redox potential the greater the tendency to lose electrons

Question 7

What is the redox potential of Complex I? Complex IV?

Answer 7

-0.32, +0.82

Question 8

NADH donates electrons to Complex I via?

Answer 8

FMN to FMNH2 (sulfur center to accept the Hydride and proton from NADH)

Question 9

NADH donates electrons via? FADH2 donates electrons via?

Answer 9

Hydride ion and proton, 2 hydrogens

Question 10

FADH2 donates electrons via complex II how?

Answer 10

Directly to CoQ

Question 11

FMNH2 is located where and how is it formed? Donates to what?

Answer 11

From NADH2 in the Complex I. Donates to CoQ

Question 12

CoQ is reduced to?

Answer 12

CoQH2

Question 13

What happens to CoQH2?

Answer 13

Donates to Iron in Complex III (cytochrome bc1)

Question 14

T or F: There are pathways for FADH2 to feed into CoQ without using Complex II

Answer 14

T

Question 15

Complex III accepts electrons from CoQH2 by?

Answer 15

Reducing Fe+3 to Fe+2

Question 16

Complex III donates to…?

Answer 16

Cytochrome C via the reduction of Fe+3 to Fe+2

Question 17

Cyto c donates to?

Answer 17

Complex IV via iron

Question 18

Complex IV donates to?

Answer 18

Oxygen (half mole of diatomic oxygen)

Question 19

Complexes I, III, and IV do what?

Answer 19

Using electron donated pump hydrogen from matrix to intermembrane space

Question 20

Which is more acidic: Matrix or intermembrane space?

Answer 20

Intermembrane space

Question 21

What is Complex V also known as?

Answer 21

ATP synthase

Question 22

What is the function of Complex V?

Answer 22

Allows protons to move from IM to MM and in doing so oxidatively phosphorylates ADP and P into ATP.

Question 23

How does ATP/ADP transport across inner membrane of mitochondria?

Answer 23

ATP/ADP co-transport that allows ATP into the IM from MM and ADP from the IM into the MM

Question 24

What are the two domains of ATP synthase?

Answer 24

F0 and F1

Question 25

Amytal rotenone blocks what step of ETC?

Answer 25

Sucicinate Dehydrogenase (electrons to CoQ)

Question 26

Antimycin A blocks what in the ETC?

Answer 26

Cyto bc1 exchange with Cyto c

Question 27

Cyanide, carbon monoxide, and sodium azide block what?

Answer 27

The transfer of electrons from Complex IV to Oxygen

Question 28

What are uncoupling proteins?

Answer 28

Proteins that create proton leaks allowing protons to move from MM to IM without capturing energy as ATP

Question 29

What is the function of Glycerol phosphate shuttle?

Answer 29

DHAP is made into Glycerol 3-phosphate via oxidation of NADH. Glycerol 3-phosphate moves from cytosol to IM. Glycerol 3-phosphate can then reduce FAD to FADH2 which then can donate directly to CoQ

Question 30

Glycerol Phosphate shuttle: What is DHAP made into in the cytosol? How?

Answer 30

DHAP to Glycerol 3-phosphate via Cystolic glycerophosphate dehydrogenase and consuming NADH and H+

Question 31

Glycerol Phosphate Shuttle: In the IM what is glycerol 3-phosphate made into?

Answer 31

DHAP vis Mitochondrial glycerophosphate dehydrogenase and making FADH2

Question 32

T or F: The Glycerol Phosphate shuttle effectively costs 1 ATP from intermediates

Answer 32

T

Question 33

What is the function of Malate aspartate shuttle?

Answer 33

Transport NADH equivalents across the membrane

Question 34

MA shuttle: Oxaloacetate is made into?

Answer 34

Malate via cytosolic malate dehydrogenase consuming a NADH and H+

Question 35

MA Shuttle: What happens to cytosolic malate?

Answer 35

Crosses into MM, and is made into oxaloacetate producing NADH and H+ via mitochondrial malate dehydrogenase

Question 36

Glycerol phosphate shuttled products feed into where in the ETC?

Answer 36

CoQ stage

Question 37

Malate aspartate shuttled products feed into where in the ETC?

Answer 37

Complex I (NADH dehydrogenase)

Question 38

What happens to oxaloacetate in the MM for MA shuttle?

Answer 38

Combines with glutamate and via amino-transferase is made into either aspartate or alpha ketoglutarate

Question 39

What is transported back into the cytosol from the matrix in MA shuttle?

Answer 39

Aspartate and Alpha-ketoglutarate which then via amino-transferase is made back into glutamate and oxaloacetate

Question 40

T or F: In the MA shuttle, glutamate is transported from the cytosol into the MM

Answer 40

T; combines with oxaloacetate to get back across into cytosol

Question 41

NADH at complex I gives how many ATP?

Answer 41

3

Question 42

NADH that is transported via the GP shuttle gives us how many ATP?

Answer 42

2

Question 43

Each FADH2 gives us how many ATP?

Answer 43

2

Question 44

What is the general function of shuttle processes?

Answer 44

Shuttle reducing equivalents from NADH generated in glycolysis from the cytosol to the mitochondria

Question 45

How much more ATP is generated from glycolysis products if MA is used instead of GP shuttle?

Answer 45

2 ATP

Question 46

How many ATP are formed via the complete oxidation of one Acetyl-CoA?

Answer 46

12 ATP

Question 47

What are three types of ROS

Answer 47

Hydroxyl radical, superoxide, and hydrogen peroxide

Question 48

What is the function of superoxide dismutase?

Answer 48

Takes 2 superoxides to Hydrogen peroxide

Question 49

What is the function of catalase?

Answer 49

Breaks down hydrogen peroxide into water and oxygen

Question 50

What happens to hydrogen peroxide in the presence of iron?

Answer 50

Made into hydroxyl radical

Question 51

How is hydrogen peroxide made into JUST water?

Answer 51

Glutathione peroxidase

Question 52

Describe the cycle of glutathione peroxidase/reductase

Answer 52

H2O2 to Water by glutathione peroxidase takes 2GSH to GSSG. GSSG is reduced to 2 GSH by glutathione reductase producing NADP+ from NADPH+

Question 53

Describe the structure of G-SH

Answer 53

Glutamate attached to cysteine attached to glycerine

Question 54

What makes NADPH for the glutathione pathway of H2O2 destruction?

Answer 54

Pentose phosphate pathway

Question 55

GSSG is _______ to 2G-SH by _______

Answer 55

reduced; Glutathione reductase

Question 56

2 G-SH is _______ to G-S-S-G by _______

Answer 56

oxidized; Glutatione peroxidase

Question 57

Which step int he glutathione process degrades H2O2?

Answer 57

Oxidizing of 2 G-SH to G-S-S-G by Glutathione peroxidase

Question 58

Glutathione reductase is accompanied by what rx?

Answer 58

NADPH + H to NADP+