Chemoorganotrophy Part 2 - Cellular Respiration (E2)

Question 1

What is the final electron acceptor for aerobic respiration?

Answer 1

Molecular oxygen

Question 2

How much ATP does aerobic respiration produce for eukaryotes and prokaryotes, respectively (HINT: It’s the opposite of what you’d expect)?

Answer 2

36 - eukaryotes
38 - prokaryotes

Question 3

Is the Kreb cycle aerobic or anaerobic?

Answer 3

It is considered an aerobic process although oxygen is not directly involved; when in cytoplasm, however, it is definitely anaerobic

Question 4

In which 2 places does the Kreb cycle occur?

Answer 4

1) Cytoplasm
2) Mitochondria

Question 5

What is the purpose of oxaloacetate in the Kreb cycle?

Answer 5

To combine with acetyl-CoA, acting as a “pick-up molecule,” thus, recontinuing the Kreb cycle

Question 6

Per original glucose, what are the 4 major products of the Kreb cycle (including the NADH produced by the prep step)?

Answer 6

1) 6 CO2
2) 8 NADH
3) 2 FADH2
4) 2 ATP

Question 7

Including the oxidation of pyruvate, how many times does the TCA cycle occur per glucose?

Answer 7

Twice

Question 8

The TCA (Kreb) cycle is amphibolic. What does this mean?

Answer 8

It is both catabolic and anabolic

Question 9

What is the anabolic function of the TCA cycle?

Answer 9

To form amino acids

Question 10

What are the 2 electron carriers for the electron transport chain?

Answer 10

NADH & FADH2

Question 11

Give the estimated amount of ATP produced via oxidative phosphorylation.

Answer 11

30+

Question 12

This is generated by an established chemical and electrical gradient.

Answer 12

What is proton motive force (PMF)?

Question 13

How does PMF aid in ATP synthesis?

Answer 13

ATP synthase catalyzes ATP synthesis via chemiosmosis established by the PMF

Question 14

Where will your main source of electron donors come from in respiration?

Answer 14

TCA cycle

Question 15

What are the 4 stages of aerobic respiration?

Answer 15

1) Glycolysis
2) Prep stage
3) Krebs
4) Oxidative phosphorylation

Question 16

In which step of aerobic respiration is oxygen not required?

Answer 16

Glycolysis

Question 17

What are the 3 major products of glycolysis?

Answer 17

2 pyruvates
2 ATP
2 NADH

Question 18

In the prep stage, the pyruvates are converted into…

Answer 18

Acetyl-CoA’s

Question 19

What is the major yield of the prep stage (HINT: electron carrier)?

Answer 19

2 NADH

Question 20

What are the 3 major products of the Krebs cycle?

Answer 20

2 ATP
6 NADH
2 FADH2

Question 21

What are the major products (electron carriers) of the electron transport chain?

Answer 21

10 NADH
2 FADH2

Question 22

What is the minor product of the electron transport chain?

Answer 22

Water

Question 23

Why is anaerobic respiration unique to prokaryotes?

Answer 23

It uses various alternative electron donors/acceptors

Question 24

The final electron acceptors of anaerobic respiration are usually…

Answer 24

Inorganic anions

Question 25

How much ATP does anaerobic respiration produce?

Answer 25

Fewer than 38 but more than 2

Question 26

The reduction of oxidized states of nitrogen for energy yield.

Answer 26

What is dissimilatory denitrification?

Question 27

Why is nitrogen reduction less effective than sulfur reduction?

Answer 27

Less ATP is produced

Question 28

What is dissimilatory metal reduction?

Answer 28

Reduction of metal cations

Question 29

With terminal electron acceptors (TEAs), as reduction potential decreases, the anaerobic environment…

Answer 29

Increases

Question 30

What is the major difference between aerobic and anaerobic benzene derivative (aromatic) catabolism (HINT: think REDOX)?

Answer 30

Aerobic - oxidative
Anaerobic - reductive

Question 31

In what 2 ways is catabolism of aromatic compounds beneficial to the environment?

Answer 31

1) Recycling lignin & other vital substances

2) Removal of pollutants