Chapter 9: Cellular Respiration and Fermentation

Which of the following pairs of pathways and their location in the cell is incorrectly matched? Electron transport chain: mitochondrion All of the responses are correctly matched. Oxidative phosphorylation: mitochondrion Glycolysis: cytosol Citric acid cycle: cytosol

Citric acid cycle: cytosol

After completion of the citric acid cycle, most of the usable energy from the original glucose molecule is in the form of __________. FADH2 ATP CO2 NADH acetyl CoA

NADH

In what molecule(s) is the majority of the chemical energy from pyruvate transferred during the citric acid cycle? Glucose Oxygen and carbon dioxide ADP ATP NADH and FADH2

NADH and FADH2

Which of the following is a correct description of the events of cellular respiration and the sequence of events in cellular respiration? Glycolysis; oxidative phosphorylation; TCA cycle; oxidation of pyruvate Oxidation of glucose to pyruvate; reduction of pyruvate; TCA cycle; oxidative phosphorylation Oxidation of pyruvate; TCA cycle; oxidation of glucose to pyruvate; oxidative phosphorylation Glycolysis; reduction of pyruvate; TCA cycle; oxidative phosphorylation Oxidation of glucose to pyruvate; oxidation of pyruvate; oxidation of acetyl-coA; oxidative phosphorylation

Oxidation of glucose to pyruvate; oxidation of pyruvate; oxidation of acetyl-coA; oxidative phosphorylation

All of the processes involved in cellular respiration produce ATP. Which of the following processes produces the most ATP? Glycolysis Citric acid cycle Oxidative phosphorylation Fermentation Substrate-level phosphorylation

Oxidative phosphorylation

Most of the electrons removed from glucose by cellular respiration are used for which of the following processes? Reducing NAD+ to NADH in glycolysis and the citric acid cycle Reducing NAD+ to NADH in glycolysis and the citric acid cycle AND producing a proton gradient for ATP synthesis in the mitochondria. Driving substrate-level phosphorylation in glycolysis Producing a proton gradient for ATP synthesis in the mitochondria Producing a proton gradient for ATP synthesis in the mitochondria AND driving substrate-level phosphorylation in glycolysis

Reducing NAD+ to NADH in glycolysis and the citric acid cycle AND producing a proton gradient for ATP synthesis in the mitochondria.

Which of the following metabolic pathways produce(s) the most ATP, per glucose molecule metabolized, during cellular respiration? Glycolysis Citric acid cycle Substrate-level phosphorylation Fermentation The electron transport chain and oxidative phosphorylation

The electron transport chain and oxidative phosphorylation

What is the total production of ATP, NADH, and FADH2 in the citric acid cycle from one molecule of glucose? The citric acid cycle does not produce any of these molecules. Four ATP only 32 ATP only Two ATP, six NADH, and two FADH2 One ATP, three NADH, and one FADH2

Two ATP, six NADH, and two FADH2

Glucose is the primary fuel for cellular respiration. Which of the following molecules can also be used by cellular respiration to generate ATP? Amino acids All of the listed responses are correct. Glycerol None of the listed responses is correct. Fatty acids

all

In the overall process of glycolysis and cellular respiration, __________ is oxidized and __________ is reduced. glucose; ATP oxygen; ATP carbon dioxide; water glucose; oxygen ATP; oxygen

glucose; oxygen

In which process is glucose oxidized to form two molecules of pyruvate? Fermentation Chemiosmosis Electron transport chain Glycolysis Citric acid cycle

glycolysis

Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule? Reduction of pyruvate to lactate Synthesis of acetyl CoA from pyruvate The electron transport chain The citric acid cycle Glycolysis

glycolysis

During aerobic respiration, molecular oxygen (O2) is used for which of the following purposes? - At the end of the electron transport chain to accept electrons and form H2O - As a source of O2 in every reaction that produces CO2 - At the end of the citric acid cycle to regenerate citric acid - Between glycolysis and the citric acid cycle to split a carbon from pyruvate, producing CO2 - At the end of glycolysis to oxidize pyruvate

- At the end of the electron transport chain to accept electrons and form H2O

Cells must regulate their metabolic pathways so that they do not waste resources. What is the most common mechanism that regulates cellular respiration in most cells? - Feedback inhibition of glycolysis - Slowing down ATP production from oxidative phosphorylation - Slowing down ATP production from fermentation - Denaturing of the enzymes in glycolysis - Positive feedback

- Feedback inhibition of glycolysis

A molecule becomes more oxidized when it __________. (H+) ion loses a hydrogen loses an electron gains a hydrogen gains an electron changes shape

loses an electron

Fermentation by itself produces no ATP but keeps glycolysis going, which produces a small amount of ATP. How does fermentation do this? - Fermentation oxidizes the carbons in pyruvate to CO2, which is then used in glycolysis. - Fermentation oxidizes NADH to NAD+, which facilitates the production of ATP in glycolysis. - Fermentation produces NADH, which fuels the electron transport chain and facilitates chemiosmosis. - Fermentation produces lactate, which keeps glycolysis going. - Fermentation reduces NAD+ to NADH, which facilitates the production of ATP in glycolysis.

- Fermentation oxidizes NADH to NAD+, which facilitates the production of ATP in glycolysis.

Which statement correctly describes the difference between alcohol fermentation and lactic acid fermentation? - Alcohol fermentation is an aerobic pathway, and lactic acid fermentation is an anaerobic pathway. - Lactic acid fermentation produces lactate, and alcohol fermentation produces ethanol. - Only lactic acid fermentation produces NAD+ to facilitate the production of ATP in glycolysis. - None of the listed responses is correct. - Alcohol fermentation produces lactate, and lactic acid fermentation produces ethanol.

- Lactic acid fermentation produces lactate, and alcohol fermentation produces ethanol.

During the energy payoff phase of glycolysis, __________. - ATP is produced - NADH is produced - NADH and ATP are produced - glucose is phosphorylated before it is split into two three-carbon molecules - glucose is phosphorylated after it is split into two three-carbon molecules

- NADH and ATP are produced

In preparing pyruvate to enter the citric acid cycle, which of the following steps occurs? - Pyruvate is reduced and decarboxylated, and the resulting electrons oxidize an NAD+ to an NADH. - Pyruvate is oxidized and decarboxylated, and the resulting electrons are donated to NADH to produce NAD+. - Pyruvate is oxidized and decarboxylated, and the removed electrons are used to reduce an NAD+ to an NADH. - Pyruvate is ionized directly to acetyl-coA. - Pyruvate is reduced to acetyl-coA, which involves the reduction of pyruvate, the addition of a carbon dioxide from the environment, and its reduction by NADH.

- Pyruvate is oxidized and decarboxylated, and the removed electrons are used to reduce an NAD+ to an NADH.

Which part of the catabolism of glucose by cellular respiration requires molecular oxygen (O2) and produces CO2? - The citric acid cycle - Glycolysis - The electron transport chain - The combination of the citric acid cycle and electron transport - The combination of glycolysis and the citric acid cycle

- The combination of the citric acid cycle and electron transport

The ATP synthase in a human cell obtains energy for synthesizing ATP directly from which of the following processes? - The reduction of oxygen - The movement of electrons through a series of carriers - The oxidation of glucose - The flow of H+ across the inner mitochondrial membrane through the ATP synthase enzyme - The oxidation of NADH and FADH2

- The flow of H+ across the inner mitochondrial membrane through the ATP synthase enzyme

The energy from the electrons in NADH and FADH2 fuel what process in the electron transport chain? - The pumping of H+ across the cristae of the mitochondrion - The oxidation of oxygen - The movement of H+ through ATP synthase - The electrons in NADH and FADH2 are not involved in the electron transport chain. - Chemiosmosis

- The pumping of H+ across the cristae of the mitochondrion

A small amount of ATP is made in glycolysis by which of the following processes? - Attachment of a free inorganic phosphate (Pi) group to ADP to make ATP - Harnessing energy from the sun - Transport of electrons through a series of carriers - Transfer of electrons and hydrogen atoms to NAD+ - Transfer of a phosphate group from a fragment of glucose to ADP by substrate-level phosphorylation

- Transfer of a phosphate group from a fragment of glucose to ADP by substrate-level phosphorylation

Fermentation is essentially glycolysis plus an extra step in which pyruvate is reduced to form lactate or alcohol and carbon dioxide. This last step __________. - removes poisonous oxygen from the environment - enables the cell to recycle the reduced NADH to oxidized NAD+ - enables the cell to make pyruvate into substances it can use - prevents pyruvate from accumulating - extracts a bit more energy from glucose

- enables the cell to recycle the reduced NADH to oxidized NAD+

During the energy investment phase of glycolysis, __________. - NADH is produced - glucose is phosphorylated after it is split into two three-carbon molecules - ATP is produced - glucose is phosphorylated before it is split into two three-carbon molecules - carbon dioxide is produced

- glucose is phosphorylated before it is split into two three-carbon molecules

Most of the ATP in cellular respiration is produced by the process of chemiosmosis. How does this process produce ATP? Phosphates are stripped from phosphorylated sugars during the energy payoff phase. Electrons from NADH and FADH2 are used to add a phosphate to ADP. Pyruvate is oxidized, providing energy to add a phosphate to ADP. Through substrate-level phosphorylation H+ flows across the inner mitochondrial membrane through the enzyme ATP synthase.

H+ flows across the inner mitochondrial membrane through the enzyme ATP synthase.

What is the role of oxygen in the electron transport chain? It is reduced to form water. It is oxidized with carbon to form CO2. It is oxidized to form ADP. Oxygen has no role in the electron transport chain. It is reduced to form CO2.

It is reduced to form water.

Most of the NADH that delivers electrons to the electron transport chain comes from which of the following processes? Anabolic pathways The citric acid cycle Substrate-level phosphorylation Oxidative phosphorylation Glycolysis

The citric acid cycle

The function of cellular respiration is to __________. reduce CO2 produce carbohydrates synthesize macromolecules from monomers extract usable energy from glucose extract CO2 from the atmosphere

extract usable energy from glucose

Muscle tissues make lactate from pyruvate to do which of the following? utilize the energy in pyruvate speed up the rate of glycolysis get rid of pyruvate produced by glycolysis produce additional CO2 regenerate NAD+

regenerate NAD+