Exam 2: Electron Transport Chain

Question 1

Which stage of respiration is the ETC?

Answer 1

Stage 4

Question 2

What is the final electron acceptor of the ETC?

Answer 2

Oxygen

Question 3

Which molecules bring electrons to complexes?

Answer 3

NADH and FADH2

Question 4

Which enzyme do protons move through?

Answer 4

ATP Synthase

Question 5

Which type of phosphorylation is used in the ETC?

Answer 5

Oxidative phosphorylation

Question 6

How many complexes are the ETC proteins organized into?

Answer 6

4 (I-IV)

Question 7

Which complexes pump protons?

Answer 7

I, III, and IV

Question 8

Where do the complexes pump protons to?

Answer 8

From the mitochondrial matrix into the intermembrane space

Question 9

What transfers electrons between complexes?

Answer 9

Q and cytochrome c

Question 10

Which complex does NADH bring electrons to?

Answer 10

Complex I

Question 11

Which complex does FADH2 bring electrons to?

Answer 11

Complex II

Question 12

What is Q?

Answer 12

The electron carrier, ubiquinone

Question 13

Q transfers electrons (and protons) between which complexes?

Answer 13

Complex I to Complex II, and Complex II to Complex III

Question 14

Cytochrome c transfers electrons between which complexes?

Answer 14

Complex III to Complex IV

Question 15

What is chemiosmosis?

Answer 15

Movement of hydrogen ions into the mitochondria

=> A process in which the proton-motive force from the ETC electrochemical gradient is used to make ATP

Question 16

Why is there a proton gradient?

Answer 16

The complexes pump protons out of the mitochondria, which means there are more protons on the outside than on the inside

Question 17

What are the 2 units of ATP synthase?

Answer 17

F0 and F1

Question 18

Which unit do protons enter ATP synthase through?

Answer 18

F0

Question 19

Once protons enter the F0 unit, what spins?

Answer 19

the rotor

Question 20

The rotor spins what?

Answer 20

the F1 unit

Question 21

Where does ATP synthesis occur?

Answer 21

on the protein subunits of the F1 unit

Question 22

How much ATP is made from the ETC?

Answer 22

25

Question 23

What polyatomic ion does E coli use as an electron acceptor?

Answer 23

nitrate (NO3-)

Question 24

Oxygen, the final electron acceptor, forms what after it receives the electrons?

Answer 24

Water

Question 25

When does anaerobic respiration occur?

Answer 25

When there is no oxygen

Question 26

What are two ways to produce ATP when there is no oxygen?

Answer 26

1. Use something other than oxygen as the final electron acceptor
2. Use only the ATP made from glycolysis (only 2 net atp)

Question 27

What happens in lactic acid fermentation?

Answer 27

Pyruvate accepts electrons from NADH, forming NAD+ and lactate

Question 28

Which types of organism undergo alcohol fermentation?

Answer 28

Yeast and bacteria

Question 29

What happens in alcohol fermentation?

Answer 29

Pyruvate is converted to acetaldehyde and CO2, acetaldehyde accepts electrons from NADH, ethanol and NAD+ are produced