Exam 3 ETC

Question 1

What is the name of complex 1 in the ETC?

How many H+ are sent into intermembrane space for each electron dropped off by NADH?

Answer 1

• NADH: Ubiquinone oxidoreductase
• 2 hydrogens for each electron

Question 2

How many electrons does Complex I carry at a time?

Why is complex I NOT a pump?

Answer 2

• 1
• Psyche - its a pump

Question 3

1. What is the name of Complex II?
2. Is this a pump or shuttle?
3. How many H+ are pumped for each electron deposited?

Answer 3

1. Succinate: Ubiquinone oxidoreductase
2. Shuttle - NOT A PUMP
3. None - since this shuttel is powered by FADH2, there is not enough energy to pump hydrogens into the intermembrane space

Question 4

What 4 “objects” reduce ubiquinone around Complex II?

Answer 4

1. Succinate: Ubiquinone oxidoreductase
2. Succinate
3. Glycerol-3-phosphate - shuttle system
4. Fatty Acyl CoA dehydrogenase

Question 5

What molecule that sounds very similar to a glycolysis intermediate shuttles electrons to the mitochondria?

Answer 5

Glycerol 3-phosphate

Question 6

What is the name of Complex III in the ETC?

Answer 6

Ubiquinol: Cytochrome C Oxidoreductase

Question 7

How many redox centers are in Complex III?

Answer 7

3!!

Question 8

What are the 3 redox centers in Complex III

Answer 8

Cytochrome C

Cytochrome B

ISP - Iron Sulfur Proteins

Question 9

How many electrons are used by Complex III at a time and how many H+ are pumped through at once?

Answer 9

• 1 electron is used
• 2 H+ are pumped
• 2 H+: 1 electron

Question 10

Is Ubiquinol:Cyctochrome C oxidoreductase a pump?

Answer 10

No

Question 11

How many ubiquinols are consumed at Complex III, NET?

Answer 11

• 1 is consumed
• 2 originally come to complex III to drop of electrons, but 1 is REMADE

Question 12

What is the name of Complex IV?

Is this complex a shuttle or pump?

Answer 12

Cyctochrome C Oxidase

Pump

Question 13

How many electrons does Cyc C deliver to Complex IV at a time?

Answer 13

1 electron

Question 14

When Cytochrome C delivers its electrons to Complex IV, how many protons are pumped to the intermembrane space?

Answer 14

1 electron : 1 H+

Question 15

• If 1 NADH starts at Complex I…how many protons will be pumped into the intermembrane space once NADH’s electrons reach Complex IV?
• What is the breakdown per Complex?
  
  • Com I
  • Com III
  • Com IV

Answer 15

• 10 H+ in total
• Complexes
  
  • I - 4 H+
  • III - 4 H+
  • IV - 2 H+

Question 16

In mammalian cells, only [] % of the energy results from proton concentration difference, while [] % is from charge difference

Answer 16

1. 20%
2. 80%

Question 17

High levels of ADP will stimulate [] production

Answer 17

ATP

Question 18

How many H+ will be needed for the synthesis of one ATP?

Answer 18

4

Question 19

Gradient energy of a single H+ is [] kcal/mol?

Synthesis of ATP requires []-[] kcal/mol

Answer 19

4.7

9-12

Question 20

How many ATP are formed from the following high energy molecules?

NADH (10 H+)

FADH2 (6 H+)

Answer 20

• NADH - 2.5
• FADH2 - 1.5

Question 21

How many turns does an ATP Synthase turn per H+ and how many total turns to make how many ATP?

Answer 21

1. 1/12 turn per H+ introduced to enzyme
2. 1, 360 degree turn equals 3 ATPs

Question 22

What did Peter Mitchell discover?

Answer 22

The kimeosmotic coupling

Question 23

What did Paul Boyer discover?

Answer 23

• The binding change mechanism of the ATP Synthase
  
  • changing of the Alpha/Beta subunits without energy expenditure

Question 24

Which subunits on the ATP synthase bind ADP and “create” the ATP?

Answer 24

Beta

Question 25

What subunit on ATP Synthase control the speed of rotation?

Answer 25

Sigma, E

Question 26

Which subunit on the ATP Synthase interacts with the Alpha/Beta subunits and coordinates their conformational change?

Answer 26

Gamma, Y

Question 27

In what conformation is ATP produced, within the ATP Synthase

Answer 27

When the Beta subunit is in the TIGHT conformation.

Question 28

What conformation, of the ATP Synthase, has a high affinity for ADP+ Pi?

Answer 28

Loose

Question 29

List examples for the following mitochondrial transporter...ie what is tranported? Monocarboxylate (requires []+?) Dicarboxylate (Depletes []+?) Tricarboxylate

Answer 29

1. Pyruvate In......OH- out -------requires H+ 2. Phosphate In.....Malate out----------depletes H+ 3. Malate In......Citrate out

Question 30

What does the Phosphate transporter do and why is it important?

Answer 30

* Transports phosphates and H+ into the mitochondria for use by ATP Synthase

Question 31

ADP is brought into the mitochondria and ATP is moved out by what transporter?

Answer 31

Adenine nucleotide translocase

Question 32

What do the following transporters transport in/out of the mitochondria? Aspartate-glutamate Trans Malate - Alpha Ketoglutarate Trans

Answer 32

1. Glutamate In......Aspartate Out 2. Malate In.......Alpha-ketoglutarate Out Used to move around Carbons and Nitrogens.

Question 33

Adenine Nucleotide Translocase 1. Transport of ATP to cytosol and ADP to lumen is favored based on []? 2. [] transport facilitate by a carrier protein

Answer 33

1. charge 2. Active transport

Question 34

What are the three substrate shuttles we learned?

Answer 34

1. Glycerol Phosphate Shuttle 2. Malate Aspartate Shuttle 3. Acetly CoA transport

Question 35

What are the 3 defense systems against reactive oxygen species that we learned?

Answer 35

1. Superoxide dismutase/catalase 2. Glutathione peroxidase/glutathione reductase 3. Dietary antioxidants

Question 36

What are 2 examples of dietary antioxidants?

Answer 36

* Vitamin E * Vitamin C

Question 37

During the reduction of Oxygen to water - what are the 3 possible reactive oxygen species that could be created?

Answer 37

1. Superoxide 1. O₂- 2. Hydrogen Peroxide 1. H₂O₂ 3. Hydroxy Radical 1. OH•

Question 38

What complex from the ETC generates the most reactive O₂?

Answer 38

Complex 1