Chapter 9: Cellular Respiration and Fermentation

A small amount of ATP is made in glycolysis by which of the following processes?

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

The function of cellular respiration is to __________

extract usable energy from glucose; The most prevalent and efficient energy-yielding pathway is cellular respiration, in which oxygen is consumed as a reactant, along with the organic fuel (frequently glucose).

Glucose is the primary fuel for cellular respiration. Which of the following molecules can also be used by cellular respiration to generate ATP? a) Glycerol b) none of the listed responses is correct c) all of the listed responses are correct d) Fatty acids e) Amino acids

All of the listed responses is correct Free glucose molecules are not common in the diets of humans and other animals. We obtain most of our calories in the forms of fats, proteins, sucrose and other disaccharides, and starch, a polysaccharide. All these organic molecules in food can be used by cellular respiration to make ATP.

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

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

Fermentation by itself produces no ATP but keeps glycolysis going, which produces a small amount of ATP. How does fermentation do this?

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

In which process is glucose oxidized to form two molecules of pyruvate?

Glycolysis

Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule?

Glycolysis

Most of the ATP in cellular respiration is produced by the process of chemiosmosis. How does this process produce ATP?

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

Which statement correctly describes the difference between alcohol fermentation and lactic acid fermentation?

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

After completion of the citric acid cycle, most of the usable energy from the original glucose molecule is in the form of __________.

NADH

During the energy payoff phase of glycolysis, __________.

NADH and ATP are produced

In what molecule(s) is the majority of the chemical energy from pyruvate transferred during the citric acid cycle?

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? a) Oxidation of pyruvate; TCA cycle; oxidation of glucose to pyruvate; oxidative phosphorylation b) Oxidation of glucose to pyruvate; oxidation of pyruvate; oxidation of acetyl-coA; oxidative phosphorylation c) Oxidation of glucose to pyruvate; reduction of pyruvate; TCA cycle; oxidative phosphorylation d) Glycolysis; reduction of pyruvate; TCA cycle; oxidative phosphorylation e) Glycolysis; oxidative phosphorylation; TCA cycle; oxidation of pyruvate

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? a) Glycolysis b) Oxidative phosphorylation c) Citric acid cycle d) Substrate-level phosphorylation e) Fermentation

Oxidative phosphorylation

In preparing pyruvate to enter the citric acid cycle, which of the following steps occurs?

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

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 AND producing a proton gradient for ATP synthesis in the mitochondria.

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

The citric acid cycle

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

The citric acid cycle does not occur in the cytosol >Glycolysis occurs in the cytosol. >The electron transport chain occurs on the cristae of the mitochondrion. >Oxidative phosphorylation occurs in the mitochondrion.

Which part of the catabolism of glucose by cellular respiration requires molecular oxygen (O2) and produces CO2?

The combination of the citric acid cycle and electron transport chain

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

The electron transport chain and oxidative phosphorylation

The ATP synthase in a human cell obtains energy for synthesizing ATP directly from which of the following processes?

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

What is the total production of ATP, NADH, and FADH2 in the citric acid cycle from one molecule of glucose?

Two ATP, six NADH, and two FADH2

Fermentation is essentially glycolysis plus an extra step in which pyruvate is reduced to form lactate or alcohol and carbon dioxide. This last step __________.

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

During the energy investment phase of glycolysis, __________.

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

In the overall process of glycolysis and cellular respiration, __________ is oxidized and __________ is reduced.

glucose; oxygen

A molecule becomes more oxidized when it __________.

loses an electron

Muscle tissues make lactate from pyruvate to do which of the following?

regenerate NAD+