BIO111 CH.9

In cellular respiration, the energy for most ATP synthesis is supplied by Question options: transferring electrons from organic molecules to pyruvate. high energy phosphate bonds in organic molecules. a proton gradient across a membrane. generating carbon dioxide and oxygen in the electron transport chain. converting oxygen to ATP.

A proton gradient across a membrane

In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of Question options: ATP, CO2, and ethanol (ethyl alcohol). ATP, pyruvate, and acetyl CoA. ATP, NADH, and pyruvate. ATP, CO2, and lactate. ATP, pyruvate, and oxygen.

ATP, CO2, and ethanol (ethyl alcohol)

Where do the catabolic products of fatty acid breakdown enter into the citric acid cycle? Question options: pyruvate α-ketoglutarate acetyl CoA malate or fumarate succinyl CoA

Acetyl CoA

Which one of the following is formed by the removal of a carbon (as CO2) from a molecule of pyruvate? Question options: lactate glyceraldehyde-3-phosphate citrate acetyl CoA oxaloacetate

Acetyl CoA

Which of the following statements describes the results of this reaction? C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy: C6H12O6 is reduced and CO2 is oxidized. O2 is reduced and CO2 is oxidized. C6H12O6 is oxidized and O2 is reduced. CO2 is reduced and O2 is oxidized. O2 is oxidized and H2O is reduced.

C6H12O6 is oxidized and O2 is reduced.

During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level? Question options: NADH FADH2 NAD+ ADP + i ATP

FADH2

A glucose molecule is completely broken down to carbon dioxide and water in glycolysis and the citric acid cycle, but together these two processes yield only a few molecules of ATP. What happened to most of the energy that the cell obtains from the oxidation of glucose? Question options: It is stored in the carbon dioxide and water molecules released by these processes. It is stored in the ATP that was formed by glycolysis and the citric acid cycle. It was lost as heat. It is stored in NADH and FADH2 It is stored in pyruvate.

It is stored in NADH and FADH2

Which of the following describes the process of glycolysis? Question options: Glycolysis produces 30 ATP from each molecule of glucose. It represents the first stage in the chemical oxidation of glucose by a cell. It requires ATP and NADH. It converts one glucose molecule to two molecules of pyruvate and carbon dioxide. Glycolysis occurs in the mitochondria.

It represents the first stage in the chemical oxidation of glucose by a cell.

Why is glycolysis described as having an investment phase and a payoff phase? Question options: It both splits molecules and assembles molecules. It uses glucose and generates pyruvate. It uses stored ATP and then forms a net increase in ATP. It attaches and detaches phosphate groups. It shifts molecules from cytosol to mitochondrion.

It uses stored ATP and then forms a net increase in ATP.

Where are the proteins of the electron transport chain located? Question options: mitochondrial intermembrane space mitochondrial outer membrane mitochondrial matrix cytosol mitochondrial inner membrane

Mitochondrial inner membrane

Which of the following statements describes NAD+? Question options: NAD+ has more chemical energy than NADH. NAD+ is oxidized by the action of hydrogenases. NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle. NAD+ can donate electrons for use in oxidative phosphorylation. In the absence of NAD+, glycolysis can still function.

NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle.

The ATP made during fermentation is generated by which of the following? Question options: oxidative phosphorylation the electron transport chain aerobic respiration chemiosmosis substrate-level phosphorylation

Substrate-level phosphorylation

In most cells, not all of the carbon compounds that participate in glycolysis and the citric acid cycle are converted to carbon dioxide by cellular respiration. What happens to the carbon in these compounds that does not end up as CO2? Question options: They are used to make NADH. These carbon compounds are used to convert ADP to ATP via chemiosmosis. They are used to make ATP from NADH. The carbon compounds are removed from these processes to serve as building blocks for other complex molecules. They are converted to heat energy.

The carbon compounds are removed from these processes to serve as building blocks for other complex molecules.

Which statement about the citric acid cycle is correct? Question options: The citric acid cycle oxidizes glucose to carbon dioxide. The citric acid cycle depends on the availability of NAD+, which is a product of glycolysis. The oxidation of compounds by the citric acid cycle requires molecular oxygen. The last reaction in the citric acid cycle produces a product that is a substrate for the first reaction of the citric acid cycle. The citric acid cycle produces most of the ATP that is subsequently used by the electron transport chain.

The last reaction in the citric acid cycle produces a product that is a substrate for the first reaction of the citric acid cycle.

When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs? Question options: The electrons gain free energy. ATP synthase pumps protons by active transport. The pH of the matrix increases. NAD+ is oxidized. The cytochromes phosphorylate ADP to form ATP.

The pH of the matrix increases.

Inside an active mitochondrion, most electrons follow which pathway? Question options: pyruvate → citric acid cycle → ATP → NADH → oxygen glycolysis → NADH → oxidative phosphorylation → ATP → oxygen citric acid cycle → FADH2 → electron transport chain → ATP electron transport chain → citric acid cycle → ATP → oxygen citric acid cycle → NADH → electron transport chain → oxygen

citric acid cycle -> NADH -> electron transport chain -> oxygen

Which process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent? Question options: the citric acid cycle oxidative phosphorylation chemiosmosis glycolysis electron transport

glycolysis

Which of the following occurs in the cytosol of a eukaryotic cell? Question options: glycolysis and fermentation fermentation and chemiosmosis citric acid cycle oxidative phosphorylation oxidation of pyruvate to acetyl CoA

glycolysis and fermentation

Phosphofructokinase is an allosteric enzyme that catalyzes the conversion of fructose 6-phosphate to fructose 1,6-bisphosphate, an early step of glycolysis. In the presence of oxygen, an increase in the amount of ATP in a cell would be expected to Question options: activate the enzyme and increase the rates of glycolysis and the citric acid cycle. inhibit the enzyme and thus increase the rate of glycolysis and the concentration of citrate. activate the enzyme and thus slow the rates of glycolysis and the citric acid cycle. inhibit the enzyme and thus increase the rates of glycolysis and the citric acid cycle. inhibit the enzyme and thus slow the rates of glycolysis and the citric acid cycle.

inhibit the enzyme and thus slow the rates of glycolysis and the citric acid cycle.

Which of the following best describes the main purpose of the combined processes of glycolysis and cellular respiration? breaking down ATP, so that ADP and P can be reused producing complex molecules from chemical building blocks the breakdown of glucose to carbon dioxide and water transforming the energy in glucose and related molecules in a chemical form that cells can use for work catabolism of sugars and related compounds

transforming the energy in glucose and related molecules in a chemical form that cells can use for work.