Ch 7

Question 1

What happens during oxidation?

Answer 1

A substance loses electrons.

Question 2

What occurs during reduction?

Answer 2

A substance gains electrons.

Question 3

What is reduced in the process of reduction?

Answer 3

The amount of positive charge.

Question 4

To which coenzyme are electrons from organic compounds first transferred?

Answer 4

NAD+.

Question 5

What is the role of NADH in cellular respiration?

Answer 5

It stores energy by presenting reduced electrons.

Question 6

What do NADH electrons pass to during cellular respiration?

Answer 6

The electron transport chain.

Question 7

What is the purpose of the energy yielded from the electron transport chain?

Answer 7

To regenerate ATP.

Question 8

What are the three stages of energy harvesting from glucose?

Answer 8

• Glycolysis
• Pyruvate oxidation
• Citric acid cycle
• Oxidative phosphorylation

Question 9

What process breaks down glucose into two molecules of pyruvate?

Answer 9

Glycolysis.

Question 10

Where does glycolysis occur?

Answer 10

In the cytosol.

Question 11

What must happen to pyruvate before the citric acid cycle can begin?

Answer 11

It must be converted to acetyl coenzyme A (acetyl CoA).

Question 12

In which organelle does pyruvate enter for oxidation in eukaryotic cells?

Answer 12

The mitochondrion.

Question 13

What completes the energy-yielding oxidation of organic molecules?

Answer 13

The citric acid cycle.

Question 14

Fill in the blank: Glycolysis is also known as _______.

Answer 14

[sugar-splitting].

Question 15

What is another name for the citric acid cycle?

Answer 15

Krebs cycle

Question 16

What does the citric acid cycle complete the breakdown of?

Answer 16

Pyruvate

Question 17

What are the products generated from one turn of the citric acid cycle?

Answer 17

• 1 ATP
• 3 NADH
• 1 FADH2
• 2 CO2

Question 18

What process couples electron transport to ATP synthesis?

Answer 18

Chemiosmosis

Question 19

What do the electron carriers donate to the electron transport chain?

Answer 19

Electrons

Question 20

What is formed when oxygen is used at protein complex IV?

Answer 20

Water

Question 21

What happens if the electron transport chain stops operating?

Answer 21

Pyruvate would not be able to enter the mitochondria, resulting in anaerobic respiration

Question 22

What are the products of anaerobic respiration in the absence of oxygen?

Answer 22

• Alcohol
• Lactic acid

Question 23

Where do electrons transfer from NADH or FADH2 go?

Answer 23

To the electron transport chain

Question 24

Does the electron transport chain generate ATP directly?

Answer 24

No

Question 25

What is the result of electron transfer in the electron transport chain?

Answer 25

Protons are pumped from the mitochondrial matrix to the intermembrane space

Question 26

What does most cellular respiration require to produce ATP?

Answer 26

Oxygen

Question 27

What will happen to the electron transport chain without oxygen?

Answer 27

It will cease to operate

Question 28

What process couples with fermentation or anaerobic respiration to produce ATP?

Answer 28

Glycolysis ## Footnote Glycolysis is the first step in both aerobic and anaerobic pathways for ATP production.

Question 29

In lactic acid fermentation, what is pyruvate reduced by to form lactate?

Answer 29

NADH ## Footnote NADH donates electrons to pyruvate in this process.

Question 30

What are the end products of lactic acid fermentation?

Answer 30

Lactate ## Footnote Lactate is produced as a result of the reduction of pyruvate.

Question 31

Which organisms are involved in lactic acid fermentation used to make cheese and yogurt?

Answer 31

Some fungi and bacteria ## Footnote Specific strains of bacteria are used in the fermentation process for dairy products.

Question 32

In alcohol fermentation, what is pyruvate converted to?

Answer 32

Ethanol ## Footnote Ethanol is produced in two steps from pyruvate.

Question 33

What is alcohol fermentation primarily used for?

Answer 33

Brewing, winemaking, and baking ## Footnote Yeast is commonly used in these fermentation processes.

Question 34

What occurs if oxygen is not present in the electron transport chain?

Answer 34

Fermentation (anaerobic respiration) occurs ## Footnote This leads to the formation of either alcohol or lactic acid.

Question 35

How many ATP are produced per glucose molecule during cellular respiration?

Answer 35

32 ATP ## Footnote This is significantly higher than the ATP yield from fermentation.

Question 36

How many ATP are produced per glucose molecule during fermentation?

Answer 36

2 ATP ## Footnote This is a much lower yield compared to cellular respiration.