Bio Ch 9

When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a hydrogen ion) the molecule becomes redoxed. oxidized. reduced. a reducing agent. hydrogenated.

Reduced

The ATP made during glycolysis is generated by photophosphorylation. electron transport. chemiosmosis. substrate-level phosphorylation. oxidation of NADH to NAD+.

Substrate-level phosphorylation

What process occurs within Box B? The figure shows the scheme of the cellular respiration. At the box A, which is located in cytosol, glucose turns into pyruvate with releasing ATP and electrons carried in NADH. The pyruvate from this stage is used in the box B, which is located in the mitochondrion. In the box B, pyruvate gets to the cycle. As a result - releasing ATP, carbon dioxide and electrons carried by NADH and FADH2. The electrons carried by NADH and FADH2 from stage A and B are used in box C for the transformation of the substance marked D into substance marked E with releasing ATP. photophosphorylation glycolysis oxidative phosphorylation the citric acid cycle electron transport

The citric acid cycle

The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation is -oxidation of glucose to CO2 and water. -the thermodynamically favorable flow of electrons from NADH to the mitochondrial electron transport carriers. -the final transfer of electrons to oxygen. -the difference in H+ concentrations on opposite sides of the inner mitochondrial membrane. -the thermodynamically favorable transfer of phosphate from glycolysis and the citric acid cycle intermediate molecules of ADP.

The difference in H+ concentrations on opposite sides of the inner mitochondrial membrane

Carbon dioxide (CO2) is released during which of the following stages of cellular respiration? -oxidation of pyruvate to acetyl CoA and the citric acid cycle -fermentation and glycolysis -the citric acid cycle and oxidative phosphorylation -oxidative phosphorylation and fermentation -glycolysis and the oxidation of pyruvate to acetyl CoA

Oxidation of pyruvate to acetyl CoA and the citric acid cycle

Which of the following produces the most ATP when glucose (C6H12O6) is completely oxidized to carbon dioxide (CO2) and water? oxidation of pyruvate to acetyl CoA fermentation oxidative phosphorylation (chemiosmosis) citric acid cycle glycolysis

Oxidative phosphorylation (chemiosmosis)

What molecule is indicated by the letter D? The figure shows the scheme of the cellular respiration. At the box A, which is located in cytosol, glucose turns into pyruvate with releasing ATP and electrons carried in NADH. The pyruvate from this stage is used in the box B, which is located in the mitochondrion. In the box B, pyruvate gets to the cycle. As a result - releasing ATP, carbon dioxide and electrons carried by NADH and FADH2. The electrons carried by NADH and FADH2 from stage A and B are used in box C for the transformation of the substance marked D into substance marked E with releasing ATP. glucose ATP water oxygen pyruvate

Oxygen

For each molecule of glucose that is metabolized by glycolysis and the citric acid cycle, what is the total number of NADH + FADH2 molecules produced? 10 4 12 6 5

12

How would anaerobic conditions (when no O2 is present) affect the rate of electron transport and ATP production during oxidative phosphorylation? (Note that you should not consider the effect on ATP synthesis in glycolysis or the citric acid cycle. -Both electron transport and ATP synthesis would stop. -Electron transport would stop but ATP synthesis would be unaffected. -Electron transport would be unaffected but ATP synthesis would stop. -Neither electron transport nor ATP synthesis would be affected.

Both electron transport and ATP synthesis would stop

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

C6H12O6 is oxidized and O2 is reduced

What is the term for metabolic pathways that release stored energy by breaking down complex molecules? bioenergetic pathways fermentation pathways catabolic pathways thermodynamic pathways anabolic pathways

Catabolic pathway

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

Citric acid cycle to NADH to electron transport chain to oxygen

When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is the lowering of pH in the mitochondrial matrix. reduction of NAD+. formation of ATP. restoration of the Na+/K+ balance across the membrane. creation of a proton gradient.

Creation of a proton gradient

NADH and FADH2 are both electron carriers that donate their electrons to the electron transport chain. The electrons ultimately reduce O2 to water in the final step of electron transport. However, the amount of ATP made by electrons from an NADH molecule is greater than the amount made by electrons from an FADH2 molecule. Which statement best explains why more ATP is made per molecule of NADH than per molecule of FADH2? -The H+ gradient made from electron transport using NADH is located in a different part of the mitochondrion than the H+ gradient made using FADH2. -Fewer protons are pumped across the inner mitochondrial membrane when FADH2 is the electron donor than when NADH is the electron donor. -FADH2 is made only in the citric acid cycle while NADH is made in glycolysis, acetyl CoA formation, and the citric acid cycle. -There is more NADH than FADH2 made for every glucose that enters cellular respiration. -It takes more energy to make ATP from ADP and Pi using FADH2 than using NADH.

Fewer protons are pumped across the inner mitochondrial membrane when FADH2 is the electron donor than when NADH is the electron donor

What process occurs in Box A? The figure shows the scheme of the cellular respiration. At the box A, which is located in cytosol, glucose turns into pyruvate with releasing ATP and electrons carried in NADH. The pyruvate from this stage is used in the box B, which is located in the mitochondrion. In the box B, pyruvate gets to the cycle. As a result - releasing ATP, carbon dioxide and electrons carried by NADH and FADH2. The electrons carried by NADH and FADH2 from stage A and B are used in box C for the transformation of the substance marked D into substance marked E with releasing ATP. electron transport electron transport and oxidative phosphorylation oxidative phosphorylation glycolysis the citric acid cycle

Glycolysis

Where is ATP synthase located in the mitochondrion? outer membrane mitochondrial matrix cytosol inner membrane electron transport chain

Inner membrane

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

Mitochondrial inner membrane

Energy released by the electron transport chain is used to pump H+ ions into which location? mitochondrial intermembrane space cytosol mitochondrial matrix mitochondrial outer membrane mitochondrial inner membrane

Mitochondrial intermembrane space

In mitochondrial electron transport, what is the direct role of O2? -to provide the driving force for the production of a proton gradient -to function as the final electron acceptor in the electron transport chain -to provide the driving force for the synthesis of ATP from ADP and Pi -to oxidize NADH and FADH2 from glycolysis, acetyl CoA formation, and the citric acid cycle

To function as the final electron acceptor in the electron transport chain