Cellular Respiration

Question 1

___ is the process that breaks down complex carbon compounds into simpler molecules and simultaneously generates the ATP used to power other metabolic processes.

Answer 1

cellular respiration

Question 2

What are the two (2) types of respiration?

Answer 2

1. aerobic
2. fermentation

Question 3

In anaerobic and aerobic respiration, respectively, what are their reactant/s?

Answer 3

anaerobic: glucose
aerobic: glucose and oxygen

Question 4

In anaerobic and aerobic respiration, respectively, what type is their combustion?

Answer 4

anaerobic: incomplete
aerobic: complete

Question 5

In anaerobic and aerobic respiration, respectively, what is their energy yield?

Answer 5

anaerobic: low (2 ATP)
aerobic: high (36-38 ATP)

Question 6

In anaerobic and aerobic respiration, respectively, what are their product/s?

Answer 6

anaerobic: lactic acid (animals), ethanol + CO2 (yeast)
aerobic: CO2 and H2O

Question 7

In anaerobic and aerobic respiration, respectively, where are they located?

Answer 7

anaerobic: cytoplasm
aerobic: cytoplasm and mitochondria

Question 8

In anaerobic and aerobic respiration, respectively, what are their stage/s?

Answer 8

anaerobic: (1) glycolysis, (2) fermentation
aerobic: (1) glycolysis, (2) link reaction, (3) Krebs cycle, (4) electron transport chain

Question 9

Is cellular respiration an anaerobic or aerobic process?

Answer 9

Cellular respiration is an aerobic process. It consumes oxygen and produces carbon dioxide (CO2).

Question 10

What is the purpose of cellular respiration?

Answer 10

to provide cells with the energy they need to function

Question 11

What are the stages of cellular respiration? (3)

Answer 11

1. glycolysis
2. citric acid cycle
3. oxidative phosphorylation

Question 12

Where does each stage of cellular respiration occur?

Answer 12

1. glycolysis - cytoplasm
2. citric acid cycle - matrix of mitochondrion
3. oxidative phosphorylation - inner membrane of cristae of the mitochondrion, electron transport, chemiosmosis

Question 13

What happens during glycolysis?

Answer 13

ATP is produced by substrate-level phosphorylation and NAD+ is reduced to NADH by electrons released from the oxidation of glucose.

Question 14

How much is the net energy yield during glycolysis?

Answer 14

2 ATP + 2 NADH

Question 15

Give a 4 step-by-step process of glycolysis.

Answer 15

1. Glucose is broken down into (2) three carbon molecules.
2. The (2) three-carbon molecules then donate high-energy electrons to (2) NAD+, forming (2) NADH.
3. Glycolysis also “banks” (4) ATP molecules directly when enzymes transfer phosphate groups from fuel molecules to ADP.
   - 2 ATP is then returned to the energy investment phase yielding 2 ATP.
4. At the end of glycolysis are two molecules of pyruvic acid.

Question 16

Before the citric acid cycle begins pyruvate is split apart and combined with an enzyme known as CoA forming a two-carbon molecule called ____.

Answer 16

acetyl-CoA

Question 17

Provide a summary of how acetyl CoA is formed from pyruvate. (3)

Answer 17

1. Each pyruvic acid loses CO2 forming (2) acetic acid.
2. Acetic acid oxidizes while (2) NAD+ reduces resulting in the formation of (2) NADH.
3. Each acetic acid is attached to coenzyme A (CoA) forming acetyl CoA.

Question 18

The citric acid cycle is also referred to as ____ or _____.

Answer 18

tricarboxylic acid cycle or Krebs cycle

Question 19

The citric acid cycle was discovered by ____.

Answer 19

Hans Adolf Krebs

Question 20

____ functions as a metabolic furnace that
oxidizes organic fuel derived from pyruvate. It breaks down acetyl CoA into carbon dioxide.

Answer 20

citric acid cycle

Question 21

The electron transport chain converts the chemical energy to a form used for ATP synthesis in the process called ____.

Answer 21

chemiosmosis

Question 22

Oxidative phosphorylation occurs in what stages? (2)

Answer 22

1. electron transport
2. chemiosmosis

Question 23

What happens during electron transport? (4)

Answer 23

1. The NADH and FADH2 release two electrons that enter an electron transport chain, a series of electron carrier molecules.
2. As the electrons pass through the ETC, it creates a concentration gradient.
3. Oxygen is the final electron acceptor at the end of the ETC and is essential for electron transport.
4. The oxygen binds with hydrogen ions forming water molecules.

Question 24

What happens during chemiosmosis? (2)

Answer 24

1. Due to the concentration gradient, the hydrogen diffuses through the inner membrane through an integral membrane protein called ATP synthase.
2. This diffusion causes the formation of ATP.

Question 25

How much is the net energy yield after glycolysis?

Answer 25

2 NADH

Question 26

How much is the net energy yield in the Krebs cycle?

Answer 26

2 ATP + 6 NADH + 2 FADH2

Question 27

How much is the net energy yield in oxidative phosphorylation?

Answer 27

34 ATP + 2 NADH