Chapter 9: Cellular Respiration and Fermentation Flashcards
What is the purpose of using multiple steps, rather than a single step, in glycolysis and the Krebs cycle to convert glucose and oxygen to carbon dioxide and water?
A) The multistep approach is the only way to convert glucose to carbon dioxide.
B) The multistep approach increases the amount of heat produced in the reaction.
C) The multistep approach increases the amount of potential energy change in the reaction.
D) The multistep approach makes better use of the potential energy in the reaction.
D) The multistep approach makes better use of the potential energy in the reaction.
Considering the reaction CH4 (methane) plus O2 yields CO2 plus H2O plus energy, which of the following is true?
A) Carbon dioxide has more potential energy than methane.
B) Methane acts as an electron donor.
C) Oxygen gas acts as an electron donor.
D) The overall reaction is endergonic.
B) Methane acts as an electron donor.
If ATP hydrolysis took place in an acidic solution such that it no longer carried negative charges, predict how the free energy released would change.
A) There will be more free energy released.
B) Less free energy will be released.
C) Hydrolysis will not take place under acid conditions.
D) There will be no change in the free energy released.
B) Less free energy will be released.
Acetyl-CoA is used in ____.
A) anabolic pathways only
B) neither anabolic nor catabolic pathways
C) catabolic pathways only
D) both anabolic and catabolic pathways
D) both anabolic and catabolic pathways
One of the purposes of the citric acid cycle is to _____.
A) oxidize NADH
B) oxidize NAD+
C) reduce NADH
D) reduce NAD+
D) reduce NAD+
Which of the following statements is true for prokaryotes that perform aerobic respiration?
A) These prokaryotes contain mitochondria.
B) They oxidize NADH at the plasma membrane.
C) They are unable to use oxygen.
D) They do not make ATP.
B) They oxidize NADH at the plasma membrane.
In the Buchner experiment, why did boiling of the yeast extract prevent the processing of sugar?
A) Yeast cells were killed.
B) Sucrose was destroyed.
C) Phosphate required for the reactions was destroyed.
D) Proteins were denatured.
D) Proteins were denatured.
Why is a different enzyme involved in each step of glycolysis?
A) Each step occurs in a different subcellular location.
B) Each step involves a different change in potential energy.
C) Each step occurs in a different cell.
D) Each step involves a different chemical reaction.
D) Each step involves a different chemical reaction.
Which of the following is true of glycolysis?
A) It only requires five distinct enzymes.
B) ATP is produced via oxidative phosphorylation.
C) It leads to the reduction of NAD+.
D) It occurs in the matrix of mitochondria.
C) It leads to the reduction of NAD+.
Which of the following compounds inhibits pyruvate dehydrogenase via feedback inhibition?
A) AMP
B) pyruvate
C) coenzyme A
D) NADH
D) NADH
During cellular respiration, the carbons present in pyruvate initially are derived from _____ and are ultimately converted to _____.
A) NAD+; ATP
B) glucose; CO2
C) glucose; ATP
D) acetyl CoA; CO2
B) glucose; CO2
As shown in Figure 9.10, citrate is the initial carboxylic acid in the citric acid pathway and oxaloacetate is the final carboxylic acid. To determine if the citric acid pathway was cyclic, Krebs treated cells with radioactive oxaloacetate. What would have been the result of Krebs’ experiment if the pathway were linear instead of circular?
A) Radioactive oxaloacetate + pyruvate would produce no radioactive citric acid cycle intermediates.
B) Radioactive oxaloacetate + pyruvate would produce radioactive acetyl CoA.
C) Radioactive oxaloacetate + pyruvate would produce radioactive citric acid.
D) Radioactive oxaloacetate + pyruvate would produce radioactive glucose.
A) Radioactive oxaloacetate + pyruvate would produce no radioactive citric acid cycle intermediates.
If glucose is fully labelled with 14C (a radioisotope of carbon), what molecule will become radioactive as glycolysis and the citric acid cycle are completed?
A) water
B) carbon dioxide
C) ATP
D) NADH
B) carbon dioxide
Under which conditions will the citric acid cycle be activated?
A) high levels of AMP
B) high levels of ATP
C) high levels of NADH
D) The citric acid cycle is not regulated; it just runs at a constant rate.
A) high levels of AMP
Which of the following is true of NADH and FADH2?
A) Only NADH donates electrons to the electron transport chain.
B) Only NADH is produced in the citric acid cycle.
C) Only FADH2 can become oxidized.
D) NADH has more potential energy than FADH2.
D) NADH has more potential energy than FADH2.
