Cellular Respiration

Question 1

What are the inputs of cellular respiration?

Answer 1

Glucose + Oxygen

Question 2

What are the outputs of cellular respiration?

Answer 2

Carbon dioxide, water, and ATP

Question 3

What is the main function/purpose of cellular respiration for cells and organisms?

Answer 3

To break down glucose (or other metabolites) in order to extract energy and produce ATP molecules to run cellular processes

Question 4

Where does glycolysis occur?

Answer 4

The cytoplasm of the cell

Question 5

Does glycolysis require oxygen?

Answer 5

No, it is an anaerobic process

Question 6

Glycolysis begins with __________. (Input)

Answer 6

Glucose

Question 7

Glycolysis ends with _____________, __________, and _________. (Outputs)

Answer 7

2 pyruvate molecules
2 net ATP
2 NADH

Question 8

How much ATP is produced per glucose molecule as a direct result of glycolysis?

Answer 8

2 net ATP
(4 ATPs are made, but 2 ATPs were used at the start of the reaction, so there is only a net gain of 2 ATPs at the end of glycolysis)

Question 9

What electron carrier is reduced in glycolysis to be used later in the electron transport chain?

Answer 9

NADH (from NAD+)

Question 10

If oxygen is available, where will the pyruvate go next?

Answer 10

To the prep reactions in the mitochondria

Question 11

What is the option after glycolysis if no oxygen is available?

Answer 11

Glycolysis can lead to fermentation (alcoholic or lactic acid fermentation) if oxygen is not available for the aerobic cellular respiration pathway in the mitochondria

Question 12

What types of organisms will use glycolysis?

Answer 12

All organisms, both prokaryotic and eukaryotic. Glycolysis occurs in the cytoplasm, so no specialized cellular structure is required, allowing the reaction to occur in simple prokaryotic cells, as well as in complex eukaryotic cells.

Question 13

Each of the following is a product of cellular respiration EXCEPT
ATP
Carbon dioxide
Oxygen
Water

Answer 13

Oxygen

Question 14

Per glucose molecule, the net gain of ATP molecules from glycolysis is

Answer 14

2

Question 15

A pathway that begins with glucose and ends with pyruvate is…

Answer 15

Glycolysis

Question 16

The pyruvate created by glycolysis can be used for

Answer 16

Entering the mitochondria for the prep reactions if oxygen is available.
Converting to alcohol or lactic acid in fermentation if oxygen is not available.

Question 17

Where do the prep reactions occur

Answer 17

matrix

Question 18

Where does the Krebs reaction occur

Answer 18

matrix

Question 19

Where does the ETC occur

Answer 19

Inner membrane

Question 20

If a certain enzyme inhibitor affects enzymes in glycolysis reactions, what types of organisms will this inhibitor impact?

Answer 20

All organisms, both prokaryotic and eukaryotic, would be affected b/c all organisms perform glycolysis.

Question 21

What are the inputs of the Prep Reaction

Answer 21

Pyruvates (also coA and NAD+)

Question 22

What are the outputs of the Prep Reaction

Answer 22

Acetyl CoA, NADH, and CO2

Question 23

Steps of the Prep Reaction

Answer 23

Prep reactions convert a 3-carbon pyruvate into a 2-carbon acetyl CoA.
Carbon is removed from pyruvate forming the 2-c acetyl and CO2 is released.
Coenzyme A is added to the acetyl and forms acetyl CoA which enters the Krebs cycle.
(This process is the same for both pyruvates.)

Question 24

What molecules are produced from the Krebs cycle?

Answer 24

CO2, 2 ATP, NADH, and FADH2

Question 25

Which of these molecules is/are given off as waste? CO2, 2 ATP, NADH, and FADH2

Answer 25

CO2

Question 26

Which of these molecules continue on to the Electron transport chain? CO2, 2 ATP, NADH, and FADH2

Answer 26

NADH and FADH2

Question 27

What are the inputs of the ETC?

Answer 27

O2, NADH, FADH2 (also ADP + P)

Question 28

What are the outputs of the ETC?

Answer 28

H2O, 32-34 ATP (also NAD+ and FAD)

Question 29

What happens to the electrons in the ETC?

Answer 29

High-energy electrons will be released from the electron carriers (NADH and FADH2) and move along the inner membrane of the mitochondria, passing from one carrier protein to the next, giving energy as they go for the pumping of H+. Electrons will then be received by oxygen, the final electron acceptor.

Question 30

What happens to the NAD+ and FAD after the ETC?

Answer 30

They will return to the earlier stages to be reduced/“recharged” again.

Question 31

Energy from the ETC is used to pump H+ from _______ to _______________________.

Answer 31

Matrix Intermembrane space

Question 32

During chemiosmosis in mitochondria, H+ builds up in the _____________. When these H+ flow _________ their concentration gradient into the matrix, _______ is produced from ADP + P.

Answer 32

Intermembrane Space Down ATP

Question 33

Explain the importance of oxygen in the ETC.

Answer 33

Oxygen is the final electron acceptor and needs to be there to collect the electrons at the end of the ETC. ETC relies on oxygen to be present in order to occur. Since the bulk of ATP is made in the ETC, without oxygen, aerobic cellular respiration could not happen, which greatly reduces the amount of energy that can be released for the cell to use.

Question 34

Water is the final product of cellular respiration. How is this water produced?

Answer 34

Oxygen picks up the electrons from the ETC and the H+ that have diffused through the ATP Synthase, forming water molecules, which will be released from the mitochondria

Question 35

Cellular respiration yields what percentage of the energy of the glucose input?

Answer 35

About 39% of the energy in glucose is harvested to produce ATP

Question 36

ATP can be produced by substrate-level phosphorylation and oxidative phosphorylation. In which stages of respiration will you find each type?

Answer 36

Glycolysis and Krebs's cycle use substrate-level phosphorylation ETC uses oxidative phosphorylation (chemiosmosis)

Question 37

How much ATP is produced in each stage of cellular respiration?

Answer 37

Glycolysis: 2 (net) ATP Prep Reactions: 0 ATP Krebs Cycle: 2 ATP ETC: 32-34 ATP Total: 36-38 ATP

Question 38

The process that evolved first was Chemiosmosis Glycolysis The electron transport chain Krebs cycle

Answer 38

Glycolysis

Question 39

Which is NOT an event of the prep reactions? Breaks down pyruvate Converts a citric acid molecule Oxidizes pyruvate Generates acetyl-CoA

Answer 39

Converts a citric acid molecule

Question 40

Select the process with the greatest yield of NADH per glucose molecule. Glycolysis Krebs cycle Prep reaction Electron transport chain

Answer 40

Kreb's Cycle

Question 41

Which of the following does NOT result in NADH? Glycolysis Krebs cycle Electron transport chain Prep reaction

Answer 41

ETC

Question 42

The coenzyme that carries the acetyl group from the prep reactions to the Krebs cycle is

Answer 42

Coenzyme A

Question 43

The final acceptor of electrons in cellular respiration is

Answer 43

Oxygen

Question 44

Which of the following reactions occurs in the cristae of the mitochondria?

Answer 44

ETC

Question 45

The process directly responsible for most of ATP formed during cellular respiration is

Answer 45

Chemiosmosis

Question 46

FADH2 is only produced where?

Answer 46

Kreb's Cycle