Test 2: Electron Transport and Oxidative Phosphorylation

Question 1

Electron transport chain:

What does complex 2 do?

Answer 1

-moves electrons to complex 3
-does not pump protons “shuttle system”

Question 2

Electron transport chain:

What does complex 4 do?

Answer 2

-moves electrons to complex 4 by cytochrome oxidase
-makes 2 H20
-respiration part?

Question 3

Electron transport chain:

What does complex 3 do?

Answer 3

?

Question 4

Electron transport chain:

Complex 1?

Answer 4

-most “leakage” happens here
-results in superoxide
-redox centers

Question 5

Where does the ETC take place?

Answer 5

mitochondria

Question 6

What is the P side?
the N side?

Answer 6

intermembrane space (positive charges)

matrix (negative charges)

Question 7

What does rate of respiration mean?

Answer 7

How much oxygen is used (in plasma cells is increased)

Question 8

_________ is proportional to rate of respiration.

Answer 8

cristae (number varies depending on metabolic needs)

Question 9

Is the outer or inner membrane more permeable?

Answer 9

outer membrane

Question 10

Q complex?

Answer 10

?

Question 11

What are the two electron shuttle systems from cytoplasm to mitochondria?

Answer 11

1. Glycerol phosphate Shuttle
2. Aspartate - Malate Shuttle

Question 12

What are the Electron Carriers in the Mitochondria?

Answer 12

-NADH + H+ & FADH2
-Iron-sulfur protein
-Ubiquinone (UQ) and Coenzyme Q (move electrons from complex to complex)
-Cytochromes (moves electrons from 3 to 4?)

Question 13

Which complexes are proton pumps?

Answer 13

complex 1, 3, 4

Question 14

Which complex makes ATP?

Answer 14

5

Question 15

How is oxidative phosphorylation regulated?

Answer 15

-availability of substrates (ADP, Pi, O2)
-oxidizable metabolism (NADH/FADH2)

Question 16

How much ATP does NADH make?
How much ATP does FADH2 make?

Answer 16

2.5

2

Question 17

Complexes ___ -___: oxidation and reduction.

Answer 17

1-4

Question 18

Proton gradient, “Chemiosmotic model”:

Were is [H+] increased?
Where is it decreased?

Answer 18

intermembrane

matrix

Question 19

Phosphorylation “complex V”:

ADP + Pi ——-> ATP by the action of ___________.

Answer 19

ATP synthase

Question 20

What are the inhibitors of Complex 1?

Answer 20

Rotenone (insecticide) and Amytal (Barbiturate)

Question 21

What is an inhibitor of complex 3?

Answer 21

Antimycin A antibiotic

Question 22

What is an inhibitor of complex 4?

Answer 22

Cyanide Azide CO

Question 23

What is an inhibitor of complex 5?

Answer 23

Oligomycin

Question 24

What are the two types of “Uncouplers” of Oxidative Phosphorylation?

Answer 24

-chemical
-physiological UC

Question 25

What are the chemical UC?

Answer 25

-2,4-dinitrophenol (DNP)
-Chlorocarbonylcyanide phenylhydrazone
(CCCP)
-Valinomycin

Question 26

What are the physiological UC?

Answer 26

-Thyroxin

-Thermogenin “Brown fat”*
bypass complex V, no
ATP synthesis but heat
generation

Question 27

Where is thermogenin present?

Answer 27

intermembrane space