Question 1

Which of the following is FALSE concerning ATP synthase?

Accepted Answer

ATP synthase is not a component of the electron transport chain; rather, it utilizes the proton gradient established by the electron transport chain to synthesize ATP through chemiosmosis in both cellular respiration and photosynthesis.

Question 2

Fatty acids typically have an even number of carbons. They are catabolized by a process called beta- oxidation. The end- products of the metabolic pathway are acetyl groups of acetyl CoA molecules. What is the most likely fate of the acetyl groups?

Accepted Answer

Acetyl groups are directly used in the Krebs cycle for energy production.

Question 3

Which of the following is true in terms of metabolism?

Accepted Answer

The reversible reaction ADP + Pi = ATP is a key reaction in energy metabolism and is linked with many other reactions in metabolic pathways, such as glycolysis and oxidative phosphorylation.

Note: None of the other choices are true. Organisms can have both catabolic and anabolic pathways, metabolic reactions existed long before eukaryotes, and oxidation-reduction reactions occur in all domains of life (including bacteria and archaea).

Question 4

Substrate level phosphorylation occurs in the citric acid cycle when Succinyl CoA is converted to Succinate. Which of the following statements about this event is true?

Accepted Answer

In the citric acid cycle, substrate-level phosphorylation occurs when Succinyl CoA is converted to Succinate, producing GTP from GDP and inorganic phosphate. GTP can then transfer its phosphate to ADP to form ATP.

Question 5

The electron transport chain

Accepted Answer

The electron transport chain is a series of redox reactions that occur in the inner membrane of the mitochondria. The chain consists of a series of electron carriers that transfer electrons from one molecule to the next, ultimately leading to the production of ATP. Substitution reactions do not occur in the electron transport chain, and it does not take place in the cytoplasm of prokaryotic cells. The electron transport chain is driven by the movement of electrons, not ATP consumption.

Question 6

After glycolysis, but before the Krebs cycle and electron transport chain/oxidative phosphorylation, most of the energy from the original glucose is in the form of which molecule?

Accepted Answer

After glycolysis, the majority of the energy from glucose is stored in the form of pyruvate molecules, which are then further processed in the Krebs cycle.

Question 7

The chemiosmotic hypothesis is an important key to understanding general metabolism because

Accepted Answer

The chemiosmotic hypothesis explains how ATP is synthesized by a proton motive force, which is a key aspect of general metabolism. It does not explain the reduction of oxygen to water, substrate-level phosphorylation, or the sequence of electron transport chain molecules.

Question 8

ATP production by ATP synthase, requiring a proton gradient across a membrane, occurs in which of the following?

Accepted Answer

ATP production by ATP synthase, requiring a proton gradient across a membrane, occurs in both oxidative phosphorylation (in aerobic respiration) and photophosphorylation (in photosynthesis). Substrate-level phosphorylation involves the direct transfer of a phosphate group from a phosphorylated substrate to ADP, without the involvement of a proton gradient.

Question 9

Pyruvate oxidation occurs in

Accepted Answer

Pyruvate oxidation occurs in the mitochondrial matrix. This is where the enzymes that convert pyruvate into acetyl CoA are located. The other options are incorrect as the cytosol is where glycolysis occurs, the mitochondrial inner membrane is where the electron transport chain and ATP synthase are located, and the mitochondrial intermembrane space is the space between the inner and outer membranes of the mitochondria.

Question 10

C₆H₁₂O₆glucose) + 6O₂-6 CO₂+ 6H₂O Where is most of the water in this reaction produced?

Accepted Answer

Most of the water in the reaction described, which is the overall equation for cellular respiration, is produced in the electron transport chain. This is the stage where oxygen is used to accept electrons, leading to the formation of water.

Question 11

CS1U1B16S1U1B0HS1U1B11S1U1B0S1U1B12S1U1B0OS1U1B16S1U1B0S1U1B1 S1U1B0+ 6 OS1U1B12S1U1B0S1U1B1 S1U1B0-6 COS1U1B12S1U1B0S1U1B1 S1U1B0+ 6 HS1U1B12S1U1B0O + Energy
-Which of the following statements describes the pathway shown above?

Accepted Answer

The pathway involves the addition and subtraction of energy (as indicated by the symbols "+ Energy" and "-6" and "+6"). This suggests that it is a catabolic pathway (breaking down molecules to release energy). The specific molecules and reactions involved cannot be determined from the given symbols. The other answer choices cannot be definitively determined from the given information.

Question 12

In cellular respiration, electrons are moved along a series of membrane proteins during the electron transport chain. If there was a mutation in the DNA coding for each of the proton pumps of the electron transport chain such that these proteins became non- functional, what would you predict to occur?

Accepted Answer

Proton pumps in the electron transport chain are responsible for moving protons (H+) from the mitochondrial matrix to the intermembrane space, creating a proton gradient. ATP synthase relies on the flow of these protons back into the matrix to generate ATP. If the proton pumps were non-functional, this gradient would not be established, and ATP synthase would not be activated, leading to a significant decrease in ATP production.

Question 13

-In the figure above, where are the enzymes of the Krebs citric acid) cycle located? Choose the arrow that corresponds.

Accepted Answer

The Krebs cycle enzymes are located in the mitochondrial matrix, which is represented by arrow A.

Question 14

Which metabolic pathway is common to both cellular respiration and fermentation?

Accepted Answer

Both cellular respiration and fermentation begin with glycolysis, the breakdown of glucose into pyruvate.

Question 15

The constituents of the electron transport chain have similar capabilities, with the exception of ubiquinone coenzyme Q). What is different about ubiquinone?

Accepted Answer

Ubiquinone is different from the other constituents of the electron transport chain because it is lipid soluble and can therefore move freely through the inner mitochondrial membrane. This allows it to transfer electrons between the different complexes in the chain.

Question 16

Why are fermentation reactions important for cells?

Accepted Answer

Fermentation reactions are important for cells as they regenerate NAD+ so that glycolysis can continue. Without fermentation, glycolysis would come to a halt due to a lack of NAD+ to accept electrons from glucose during the process. Therefore, cells rely on fermentation to keep producing ATP through glycolysis even in the absence of oxygen. Choices A, C, and D are incorrect as fermentation reactions do not utilize or generate oxygen or produce alcohol as a primary function.

Question 17

The energy of electron transport serves to move translocate) protons to the outer mitochondrial compartment. How does this help the mitochondrion to produce energy?

Accepted Answer

The translocation of protons to the outer mitochondrial compartment creates an electrochemical gradient, with a higher concentration of protons in the outer compartment than in the inner compartment. This gradient can then be used by ATP synthase to generate ATP from ADP and inorganic phosphate, in a process called oxidative phosphorylation. Therefore, translocating protons helps the mitochondria produce energy by creating the electrochemical gradient necessary for ATP synthesis.

Question 18

The inner mitochondrial membrane normally

Accepted Answer

The inner mitochondrial membrane contains the electron transport chain and ATP synthase, which use the proton gradient created by the active transport pump to generate ATP. Therefore, the membrane must be impermeable to hydrogen ions in order for this system to work efficiently. Permease channels and enzymes responsible for glycolysis are located in other parts of the mitochondria, such as the outer membrane and matrix.

Question 19

The ATP made during fermentation is generated by

Accepted Answer

Fermentation produces ATP through substrate-level phosphorylation, in which a phosphate group is transferred from a substrate molecule to ADP to form ATP. It does not involve the electron transport chain, oxidative phosphorylation, or chemiosmosis, which are involved in aerobic respiration.

Question 20

During the electron transport chain, cytochrome oxidase catalyzes the transfer for electrons from cytochrome c to oxygen in the mitochondria. Cyanide is a poison that inhibits the enzyme cytochrome oxidase. When cyanide is present, what will happen?

Accepted Answer

Cyanide inhibits the function of cytochrome oxidase, which is a crucial enzyme in the electron transport chain. As a result, electrons are no longer able to flow through the chain and the electron transport chain shuts down. This leads to a halt in ATP production, which can be fatal for organisms relying on the process for energy. Glycolysis and Kreb's cycle will also be impacted indirectly as they depend on electron transport chain to produce their intermediate products.

Quiz 9: Cellular Respiration and Fermentation

Which of the following is FALSE concerning ATP synthase?

Fatty acids typically have an even number of carbons. They are catabolized by a process called beta- oxidation. The end- products of the metabolic pathway are acetyl groups of acetyl CoA molecules. What is the most likely fate of the acetyl groups?

Which of the following is true in terms of metabolism?

Substrate level phosphorylation occurs in the citric acid cycle when Succinyl CoA is converted to Succinate. Which of the following statements about this event is true?

The electron transport chain

After glycolysis, but before the Krebs cycle and electron transport chain/oxidative phosphorylation, most of the energy from the original glucose is in the form of which molecule?

The chemiosmotic hypothesis is an important key to understanding general metabolism because

ATP production by ATP synthase, requiring a proton gradient across a membrane, occurs in which of the following?

Pyruvate oxidation occurs in

C₆H₁₂O₆glucose) + 6O₂-6 CO₂+ 6H₂O Where is most of the water in this reaction produced?

C₆H₁₂O₆+ 6 O₂-6 CO₂+ 6 H₂O + Energy -Which of the following statements describes the pathway shown above?

-In the figure above, where are the enzymes of the Krebs citric acid) cycle located? Choose the arrow that corresponds.

Which metabolic pathway is common to both cellular respiration and fermentation?

The constituents of the electron transport chain have similar capabilities, with the exception of ubiquinone coenzyme Q) . What is different about ubiquinone?

Why are fermentation reactions important for cells?

The energy of electron transport serves to move translocate) protons to the outer mitochondrial compartment. How does this help the mitochondrion to produce energy?

The inner mitochondrial membrane normally

The ATP made during fermentation is generated by

During the electron transport chain, cytochrome oxidase catalyzes the transfer for electrons from cytochrome c to oxygen in the mitochondria. Cyanide is a poison that inhibits the enzyme cytochrome oxidase. When cyanide is present, what will happen?

Quiz 9: Cellular Respiration and Fermentation

Which of the following is FALSE concerning ATP synthase?

Fatty acids typically have an even number of carbons. They are catabolized by a process called beta- oxidation. The end- products of the metabolic pathway are acetyl groups of acetyl CoA molecules. What is the most likely fate of the acetyl groups?

Which of the following is true in terms of metabolism?

Substrate level phosphorylation occurs in the citric acid cycle when Succinyl CoA is converted to Succinate. Which of the following statements about this event is true?

The electron transport chain

After glycolysis, but before the Krebs cycle and electron transport chain/oxidative phosphorylation, most of the energy from the original glucose is in the form of which molecule?

The chemiosmotic hypothesis is an important key to understanding general metabolism because

ATP production by ATP synthase, requiring a proton gradient across a membrane, occurs in which of the following?

Pyruvate oxidation occurs in

C6H12O6 glucose) + 6O2 -6 CO2 + 6H2O Where is most of the water in this reaction produced?

C6H12O6 + 6 O2 -6 CO2 + 6 H2O + Energy -Which of the following statements describes the pathway shown above?

-In the figure above, where are the enzymes of the Krebs citric acid) cycle located? Choose the arrow that corresponds.

Which metabolic pathway is common to both cellular respiration and fermentation?

The constituents of the electron transport chain have similar capabilities, with the exception of ubiquinone coenzyme Q) . What is different about ubiquinone?

Why are fermentation reactions important for cells?

The energy of electron transport serves to move translocate) protons to the outer mitochondrial compartment. How does this help the mitochondrion to produce energy?

The inner mitochondrial membrane normally

The ATP made during fermentation is generated by

During the electron transport chain, cytochrome oxidase catalyzes the transfer for electrons from cytochrome c to oxygen in the mitochondria. Cyanide is a poison that inhibits the enzyme cytochrome oxidase. When cyanide is present, what will happen?

C₆H₁₂O₆glucose) + 6O₂-6 CO₂+ 6H₂O Where is most of the water in this reaction produced?

C₆H₁₂O₆+ 6 O₂-6 CO₂+ 6 H₂O + Energy -Which of the following statements describes the pathway shown above?