Question 1

The most commonly accepted hypothesis for the production of ATP that results from electron transport system is called the __________ hypothesis.

Accepted Answer

The answer of The most commonly accepted hypothesis for the...

Question 2

Bacterial electron transport chains may be comprised of fewer components and have lower P/O ratios than mitochondrial transport chains.

Accepted Answer

Bacterial electron transport chains typically have fewer components, such as fewer cytochromes and fewer complexes, and may have a lower P/O ratio (ATP produced per oxygen molecule reduced) than mitochondrial transport chains.

Question 3

In aerobic conditions, it takes __________ sugar to produce the same amount of ATP when compared to anaerobic conditions.

Accepted Answer

In aerobic conditions, the process of cellular respiration can occur, which produces a much larger amount of ATP from the same amount of sugar compared to anaerobic conditions. Therefore, less sugar is required in aerobic conditions to produce the same amount of ATP.

Question 4

When mitochondria pass electrons donated by NADH through the electron transport chain to molecular oxygen, a theoretical maximum of __________ molecules of ATP can be made per oxygen molecule reduced.

Accepted Answer

The answer of When mitochondria pass electrons donated by NADH...

Question 5

The theoretical maximum net gain of ATP per molecule of glucose metabolized aerobically in eukaryotes is

Accepted Answer

The theoretical maximum net gain of ATP per molecule of glucose in eukaryotes is 38, which is the result of the complete oxidation of glucose through aerobic respiration. This includes the production of 2 ATP from glycolysis, 2 ATP from the Krebs cycle, and 34 ATP from oxidative phosphorylation. While some sources may list a maximum of 36 ATP due to variations in the number of protons required for ATP synthase activity, the most widely accepted value is 38 ATP.

Question 6

In addition to being used in the making of ATP, proton motive force is used directly to power the rotation of bacterial flagella.

Accepted Answer

Proton motive force is used to power the rotation of bacterial flagella in a process called chemotaxis. This allows bacteria to move towards or away from certain chemicals in their environment.

Question 7

Fermentation involves the use of pyruvate and/or other organic molecules as electron acceptors.

Accepted Answer

In fermentation, organic molecules such as pyruvate are used as electron acceptors. This allows for the regeneration of NAD+ which is needed for glycolysis to continue.

Question 8

In higher eukaryotes, most aerobically generated ATP is produced by

Accepted Answer

While glycolysis and the TCA cycle generate a small amount of ATP, the majority of aerobic ATP production occurs during oxidative phosphorylation in the electron transport chain. This involves a membrane-bound proton translocating ATP synthase generating ATP by coupling the movement of protons down their concentration gradient to the phosphorylation of ADP.

Question 9

Organisms that form lactate, ethanol, and CO₂ as end products of glucose metabolism are called __________ fermenters.

Accepted Answer

The answer of Organisms that form lactate, ethanol, and CO₂...

Question 10

Which of the following is NOT true regarding ATP synthases?

Accepted Answer

The proton flow is actually inward during ATP synthesis in mitochondria. Therefore, statement C is not true.

Question 11

The electron transport systems in eukaryotes and prokaryotes use different electron carriers.

Accepted Answer

Eukaryotic electron transport systems use NADH and FADH2 as electron carriers, while prokaryotic systems can use a variety of electron carriers including quinones, cytochromes, and iron-sulfur proteins.

Question 12

Which of the following can be used as electron acceptors during anaerobic respiration?

Accepted Answer

All of the choices can be used as electron acceptors during anaerobic respiration. Nitrate is commonly used by bacteria such as Escherichia coli and Pseudomonas aeruginosa, sulfate is commonly used by bacteria such as Desulfovibrio and Desulfobacter, and carbon dioxide can be used by some methanogenic archaea.

Question 13

Production of ATP using the energy liberated when electrons from reduced chemical bonds are passed through the electron transport system is generally referred to as __________.

Accepted Answer

The answer of Production of ATP using the energy liberated...

Question 14

The major function(s) of the TCA cycle is(are)

Accepted Answer

The TCA cycle (also known as the Krebs cycle or citric acid cycle) serves two main functions: (1) energy production in the form of ATP, through the oxidation of acetyl CoA and the transfer of electrons to the electron transport chain, and (2) provision of carbon skeletons (such as oxaloacetate, alpha-ketoglutarate, and succinyl-CoA) for use in biosynthesis of other molecules, such as amino acids, fatty acids, and nucleotides. Therefore, choice D is the best choice since it encompasses both functions of the TCA cycle.

Question 15

When cells of a facultative anaerobe such as Paracoccus denitrificans are growing under anaerobic conditions and using nitrate as the terminal electron acceptor, ______________ nitrate reduction is occurring.

Accepted Answer

The answer of When cells of a facultative anaerobe such...

Question 16

The number of ATP molecules generated per atom of oxygen that is reduced when electrons are passed from NADH or reduced FAD (FADH) to O₂ is called the

Accepted Answer

The P/O ratio (phosphate/oxygen) is defined as the number of ATP molecules generated per atom of oxygen that is reduced when electrons are passed from NADH or reduced FAD (FADH) to O₂ through the electron transport chain. It represents the efficiency of oxidative phosphorylation, which is the final step of cellular respiration where ATP is produced by the phosphorylation of ADP using energy released by the ETC. Therefore, the P/O ratio is the best choice for this question as it directly relates to the energy yield of cellular respiration.

Question 17

Prokaryotes may use several different terminal oxidases for the electron transport system.

Accepted Answer

Prokaryotes have multiple terminal oxidases that can be used in their electron transport chain, allowing for flexibility in energy production depending on the available oxygen and other electron acceptors in their environment.

Question 18

Reduction of nitrate to nitrite by Paracoccus denitrificans is an example of anaerobic respiration.

Accepted Answer

Nitrate reduction to nitrite is a type of anaerobic respiration as it occurs in the absence of oxygen. Paracoccus denitrificans is a facultative anaerobe that is capable of performing this process.

Question 19

The hypothesis that proton motive force drives ATP synthesis is called the __________ hypothesis.

Accepted Answer

The answer of The hypothesis that proton motive force drives...

Question 20

Mitochondrial electron transport takes place

Accepted Answer

Mitochondrial electron transport takes place on the inner mitochondrial membrane. This is where the electron transport chain proteins are embedded and where the proton gradient is formed during oxidative phosphorylation.

Quiz 10: Catabolism Energy Release and Conservation