Chapter 9

Question 1

Why do we call cellular respiration a metabolic pathway?

Answer 1

Because it is a catabolic pathway that releases stored energy by breaking down complex molecules.

Question 2

What is the function of cellular respiration?

Answer 2

To break down glucose to make ATP

Question 3

What are the reactants of cellular respiration?

Answer 3

glucose and oxygen

Question 4

What are the products of cellular respiration?

Answer 4

ATP, carbon dioxide, and water

Question 5

Redox reactions

Answer 5

Chemical reactions that transfer electrons between reactants

Question 6

What happens when a substrate is reduced?

reduction

Answer 6

The substance gains electrons

Question 7

What happens when the substrate is oxidized?

oxidation

Answer 7

The substance loses electrons

Question 8

acronym to remember reduction vs oxidation

Answer 8

LEO says GER

L: lose; E: electrons; O: oxidation

G: gain; E: electrons; R: reduction

Question 9

Is cellular respiration a redox reaction?

Answer 9

yes

Question 10

In cellular respiration, which molecule is being oxidized

Answer 10

Na (sodium)

Question 11

in cellular respiration, which molecule is being reduced?

Answer 11

Cl (chlorine)

Question 12

Why is it more favorable for an organism to release energy through the steps of cellular respiration instead of all at once?

Answer 12

If energy is released from fuel all at once, it cannot be harnessed efficiently for constructive work.

Question 13

In what parts of the cell do the metabolic pathways of cellular respiration take place?

Answer 13

mitochondria and cytoplasm

Question 14

What are the energetic and/or product outputs of glycolysis?

Answer 14

2 pyruvate, 2 NADH, 2 H+ and 4 ATP

Question 15

What are the energetic and/or product outputs of the citric acid cycle?

Answer 15

2 ATP, 6 NADH, 2 FADH2

Question 16

What are the energetic and/or product outputs of oxidative phosphorylation?

Answer 16

about 26-28 ATP

Question 17

Where does glycolysis occur? Is this process aerobic?

Answer 17

In the cytoplasm, not aerobic

Question 18

What are the two phases in glycolysis?

Answer 18

Energy investment phase: 2 ATP are used during this

Energy payoff phase: 4 ATP made

Question 19

At what phase in glycolysis is energy used?

Answer 19

first phase (energy investment phase)

Question 20

What enzyme is responsible for starting the reactions of glycolysis?

Answer 20

Hexokinase

Question 21

GLYCOLYSIS: What enzyme is responsible for splitting the glucose molecule in two?

Answer 21

Aldolase

Question 22

GLYCOLYSIS: What enzyme is responsible for converting dihydroxyacetone phosphate into glyceraldehyde-3-phosphate (G3P)?

Answer 22

Isomerase

Question 23

GLYCOLYSIS: What enzyme is responsible for converting phosphoenolpyruvate (PEP) into pyruvate?

Answer 23

Pyruvate kinase

Question 24

At what point in glycolysis are electrons harvested?

Answer 24

Beginning of the second phase (energy payoff phase)

Question 25

GLYCOLYSIS: What molecules are the electrons attached to?

Answer 25

NADH

Question 26

GLYCOLYSIS: What is that molecule called when it has or does not have the electrons?

Answer 26

With electrons is called NADH and without electrons is called NAD+

Question 27

GLYCOLYSIS: Where do the electrons go?

Answer 27

Electrons get transferred to NAD+ to store energy in form NADH

Question 28

At what point is ATP synthesized during glycolysis?

Answer 28

In the energy payoff phase

Question 29

What is the final product of glycolysis?

Answer 29

2 pyruvate, 2 H2O, and 4 ATP

Question 30

For each glucose molecule that enters glycolysis how many of these final products are produced?

Answer 30

2 ATP molecules are produced

Question 31

CITRIC ACID CYCLE: Describe the process that converts pyruvate to Acetyl CoA.

Answer 31

Before the citric acid cycle can begin, pyruvate must be converted to acetyl Coenzyme A (acetyl CoA), which links glycolysis to the citric acid cycle

Question 32

CITRIC ACID CYCLE: What enzyme complex converts pyruvate into Acetyl CoA?

Answer 32

Pyruvate dehydrogenase complex

Question 33

CITRIC ACID CYCLE: At what point is CO2 released and why?

Answer 33

When the pyruvate enters the mitochondria

Question 34

Where in the cell does the citric acid cycle take place?

Answer 34

In the mitochondria

Question 35

CITRIC ACID CYCLE: Does substrate-level phosphorylation occur, how many times per cycle?

Answer 35

Yes, 1 time per cycle

Question 36

CITRIC ACID CYCLE: What is produced as a result of each cycle?

Answer 36

Each cycle produced 3 NADH, 1 FADH2, and 1 ATP

Question 37

Is the citric acid cycle aerobic?

Answer 37

Yes.

Question 38

CITRIC ACID CYCLE: where substrate-level phosphorylation is occurring

Answer 38

Phosphorylation occurs in step 5

Question 39

CITRIC ACID CYCLE: Where do the electrons that are harvested go?

Answer 39

The electron transport chain

Question 40

CITRIC ACID CYCLE: At what point is CO2 released and why?

Answer 40

- When the D- isocitrate is converted to a-ketoglutarate | - When the a-ketoglutarate is converted to succinyl CoA

Question 41

Where in the mitochondria does oxidative phosphorylation occur?

Answer 41

In the inner membrane, far right

Question 42

What molecules carry electrons to the machinery of oxidative phosphorylation?

Answer 42

Cytochromes

Question 43

Explain how the electron transport chain builds up a hydrogen ion (proton) gradient across the membrane.

Answer 43

Electron transfer in the electron transport chain causes proteins to pump H+ from the mitochondrial matrix to the intermembrane space.

Question 44

Where is the concentration the greatest? (electron transport chain)

Answer 44

In the inner membrane space

Question 45

Is the process of oxidative phosphorylation aerobic?

Answer 45

Yes. Without oxygen, the electron transport chain will cease to operate.

Question 46

Compared to glycolysis and the citric acid cycle, how would you describe the amount of ATP that oxidative phosphorylation produces?

Answer 46

It produces the most ATP. Around 26 or 28 ATP.

Question 47

Is glucose the only substrate that can be metabolized through aerobic cellular respiration?

Answer 47

No. Proteins, lipids, and carbohydrates can also be metabolized through aerobic cellular respiration.

Question 48

Fermentation

Answer 48

Fermentation uses substrate-level phosphorylation instead of an electron transport chain to generate ATP

Question 49

What are the reactants of fermentation?

Answer 49

glucose and yeast

Question 50

What are the products of fermentation?

Answer 50

Ethanol, CO2, and ATP

Question 51

Lactic Acid fermentation

Answer 51

NADH is reduced to NADH with no release of CO2. Humans use lactic acid fermentation to generate ATP when O2 is scarce

Question 52

Ethanol fermentation

Answer 52

pyruvate is converted to ethanol in two steps and Co2 is released.

Question 53

Explain how anaerobic respiration is different from aerobic respiration and fermentation.

Answer 53

Anaerobic respiration does not require o2 to produce ATP. And fermentation uses substrate-level phosphorylation instead of an electron transport chain to generate ATP.

Question 54

Compare and contrast the similarities and differences between a facultative anaerobe and an obligate anaerobe.

Answer 54

Obligate anaerobes carry out fermentation or anaerobic respiration and cannot survive in the presence of O2.

Question 55

What groups of organisms exhibit each of these adaptations? (facultative anaerobe)

Answer 55

Yeast and many bacteria are facultative anaerobes, meaning they survive using fermentation or cellular respiration,

Question 56

Chemiosmosis

Answer 56

Involves the pumping of protons through special channels in the membranes of mitochondria from the inner to the outer compartment which makes ATP. Hydrogen ions in the intermembrane space diffuse back into the matrix by diffusion via ATP Synthase.