Module 7 (Cellular Respiration)

Question 1

Cellular Respiration

Answer 1

Converts energy in fuel molecules to ATP
- Allows the cell to do work
- Catabolic

Question 2

Stages of Cellular Respiration

Answer 2

1. Glycolysis
2. Pyruvate Oxidation
3. Citric Acid cycle
4. Oxidative phosphorylation

Question 3

Substrate-level Phosphorylation

Answer 3

ADP becomes phosphorylated through a hydrolysis reaction involving an enzyme pathway (not a lot of energy is made)

Question 4

Oxidative Phosphorylation

Answer 4

• Needs oxygen
• Using electron carriers in the electron transport chain to phosphorylate ADP and create ATP

Question 5

Phosphorylation

Answer 5

Adding Pi to ADP

Question 6

Where does glycolysis take place?

Answer 6

In the cytoplasm

Question 7

Where does Pyruvate Oxidation take place?

Answer 7

Intermembrane space

Question 8

Where does citric acid cycle occur?

Answer 8

Mitochondrial matrix

Question 9

Where does oxidative phosphorylation occur?

Answer 9

Inner membrane

Question 10

What is the purpose of glycolysis?

Answer 10

To partially break down glucose and create pyruvate, and release a small amount of energy

Question 11

What is the purpose of pyruvate oxidation?

Answer 11

To convert pyruvate into acetyl-CoA and CO2

Question 12

What is the purpose of the Kreb’s cycle?

Answer 12

To produce electron carriers from acetyl-CoA (and a little bit of ATP)

Question 13

What is the purpose of oxidative phosphorylation?

Answer 13

Electron carriers lose their electrons and transfer them to the electron transport chain, produces A LOT of ATP

Question 14

In what stages does substrate level phosphorylation occur?

Answer 14

In glycolysis and the citric acid cycle

Question 15

Electron carriers in Cellular respiration

Answer 15

NAD+ and FAD

Question 16

Oxidation in Cellular Respiration

Answer 16

Glucose is oxidized to CO2 while energy is harnessed in electron carriers

Question 17

Reduction in Cellular Respiration

Answer 17

• O2 is reduced to form H2O
• Electrons move from one molecule to the next during cellular respiration through reduction reactions

Question 18

Oxidized forms of NADH and FADH2

Answer 18

NAD+ and FAD

Question 19

Reduced forms of NAD+ and FAD

Answer 19

NADH and FADH2
(high potential energy)

Question 20

Glycolysis is considered a…

Answer 20

Universal pathway (occurs in every cell)

Question 21

Preparatory Phase of glycolysis

Answer 21

Where energy is consumed

Question 22

Cleavage phase of glycolysis

Answer 22

Where glucose is split into two

Question 22

Payoff phase of glycolysis

Answer 22

Where ATP and NADH is produced

Question 23

Events of the preparatory phase

Answer 23

Addition of two phosphate groups, producing fructose 1,6-bisphosphate
- Traps glucose inside cell and destabilizes it

Question 24

Events of cleavage phase

Answer 24

Fructose 1,6-bisphosphate splits into glyceraldehyde 3-phosphate and dihydroxyacetone phosphate (which is then converted into G3P)

Question 25

Events of Payoff phase

Answer 25

• Two pyruvate produced
• Two NADH produced
• Four ATP produced

Question 26

Inter membrane space

Answer 26

Space between two membranes of the mitochondria

Question 27

Mitochondrial matrix

Answer 27

The space inside the inner membrane

Question 28

Pyruvate Oxidation

Answer 28

(aerobic)
- Pyruvate is oxidized to produce carbon dioxide and a acetyl group, and NADH
- Eventually forms acetyl-CoA (added to coenzyme A)

Question 29

What group of enzymes catalyze the reactions of pyruvate oxidation?

Answer 29

Pyruvate dehydrogenase complex

Question 30

Pyruvate oxidation products

Answer 30

1 CO2 x2
1 NADH x2
1 acetyl-CoA x2

Question 31

Citric Acid cycle is also known as…

Answer 31

Krebs cycle and TCA cycle

Question 32

Citric acid cycle

Answer 32

Completes the oxidation of glucose, produces CO2, NADH and FADH2

Question 33

GTP

Answer 33

Guanosine Triphosphate - used to produce ATP

Question 34

How is GTP produced?

Answer 34

Through substrate-level phosphorylation in the Kreb’s cycle

Question 35

Use of Intermediates in the Kreb’s cycle

Answer 35

Some organisms use intermediate products in other metabolic pathways
- a-Ketoglutarate can be modified to form other amino acids and purine bases

Question 36

Electron Transport Chain

Answer 36

(ETC, aeorbic)
- Electrons from NADH and FADH2 move from donor to acceptor until oxygen (final electron acceptor) reduces to H20

Question 37

Proton Gradient in the ETC

Answer 37

Intermembrane space (high)
Mitochondrial matrix (low)
- Stores potential energy for ATP synthesis

Question 38

ATP synthase

Answer 38

Powered by the proton gradient, it allows the protons to travel back to the matrix, which rotates a protein subunit
- Converts chemical energy into energy in bonds of ATP

Question 39

Anaerobic Conditions in bacteria and animals

Answer 39

Lactic Acid pathway
Glucose + 2ADP +2Pi -> lactic acid + 2 ATP + 2 H20

Question 40

In anaerobic conditions, plants and fungi undergo…

Answer 40

Ethanol fermentation

Question 41

Ethanol Fermentation Process

Answer 41

Pyruvate releases CO2 (forms acetaldehyde), electrons from NADH transferred to acetaldehyde to produce ethanol and NAD+

Question 42

Plants store excess glucose as…

Answer 42

Starch

Question 43

Animals store extra glucose as…

Answer 43

Glycogen
(Stored in muscle cells for contraction energy, liver for whole body)

Question 44

Why are lipids an excellent energy source?

Answer 44

They are rich in C-C and C-H bonds

Question 45

beta-oxidation

Answer 45

Shorten fatty acids, lipids are broken down into glycerol and acetyl-CoA
(ATP is not produced directly)