Chapter 4 - Cellular Respiration

Question 1

What is aerobic respiration?

Answer 1

Process that uses oxygen to harvest energy from organic compounds
Process that extracts energy from food in the presence of oxygen

Question 2

What are Obligate Aerobes?

Answer 2

These are organisms that cannot survive without oxygen

Question 3

Aerobic cellular respiration can be broken down into how many stages?

Answer 3

4 stages

Question 4

Each stage of the cellular respiration produces ATP using how many methods? What’re they?

Answer 4

2;
Substrate-level Phosphorylation
Oxidative Phosphorylation

Question 5

What is substrate level phosphorylation?

Answer 5

ATP that can be directly formed through an enzyme-catalyzed reaction that transfers a phosphate group from a substrate to ADP

Question 6

What is oxidative phosphorylation?

Answer 6

Forming ATP indirectly through a series of redox reactions involving a final electron acceptor

Question 7

What is the first stage of cellular respiration?

Answer 7

Glycolysis

Question 8

Where does Glycolysis occur?

Answer 8

In the cytosol

Question 9

What occurs during Glycolysis?

Answer 9

Enzymes break down a molecule of glucose into 2 pyruvate molecules. Some ATP and NADH is synthesized as well

Question 10

What is the second step in cellular respiration?

Answer 10

Pyruvate Oxidation

Question 11

What occurs during Pyruvate Oxidation?

Answer 11

The 2 pyruvate molecules made in glycolysis are transported to the Mitochondria and they’re oxidized resulting in NADH and Acetyl-coA (coenzyme A), along with CO2 as a waste product

Question 12

Where does Pyruvate Oxidation occur?

Answer 12

In the Mitochondria

Question 13

What is the third step in cellular respiration?

Answer 13

Citric Acid Cycle

Question 14

Where does the Citric Acid Cycle occur?

Answer 14

In the Mitochondria

Question 15

What happens during the Citric Acid Cycle?

Answer 15

Acetyl-CoA which was made during pyruvate oxidation enter a cycle where the acetyl group is completely oxidized to CO2. ATP and electron carried NADH and FADH2 are synthesized.

Question 16

What is the last step in cellular respiration?

Answer 16

Electron transport chain

Question 17

What occurs during the electron transport chain?

Answer 17

The NADH and FADH2 from the Citric Acid Cycle are oxidized. Their high energy electrons are passed from one oxidizing agent to another until they are transferred to O2, producing water. The free energy released during electron transport is indirectly used to synthesize ATP by oxidative phosphorylation

Question 18

What 3 steps of cellular respiration use substrate level phosphorylation to synthesize ATP?

Answer 18

Glycolysis, pyruvate oxidation, and citric acid cycle

Question 19

What step used oxidative phosphorylation to synthesize ATP?

Answer 19

Electron transport chain

Question 20

Describe the structure of the mitochondria?

Answer 20

• Comprised of 2 membranes
• Outer and inner membranes define 2 compartments
• Intermembrane space is between inner and outer membrane
• Matrix is the inner aqueous environment of the organelle

Question 21

How many processes are there which allow cells to oxidize fuel molecules WITHOUT oxygen? What are they?

Answer 21

2;

• Anaerobic respiration
• Fermentation

Question 22

What is anaerobic respiration?

Answer 22

Similar to aerobic respiration in using a series of electron transferring steps, but it uses an INORGANIC molecule other than oxygen as the final oxidizing agent

Question 23

What is Fermentation?

Answer 23

Doesn’t use the electron transport system and instead it relies on an ORGANIC compound as the final oxidizing agent

Question 24

What are obligate anaerobes?

Answer 24

These are organisms that cannot survive IN the presence of oxygen

Question 25

What are facultative anaerobes?

Answer 25

These are organisms that can live with or without oxygen