Exam 9: Pathways That Harvest Chemical Energy

The loss of a(n) _______ by a ferrous ion (Fe²⁺) to yield a ferric ion (Fe³⁺) is called oxidation.

Which reaction is not an oxidation-reduction reaction?

The reaction equation that represents the chemical change resulting from glycolysis followed by cellular respiration is C₆H₁₂O₆ + 6 O₂  6 CO₂ + _______ ATP + 6 _______.

ATP synthase is the protein complex that

Some microbes use non-O₂ electron acceptors to complete the electron transport chain.An example of an organism that carries out this type of electron transport is a soil bacterium that takes in nitrate (NO₃⁻) and releases nitrogen gas (N₂).The nitrate functions as a(n)

Refer to the figure below. Of the two compounds that react as shown in the figure, compound _______ has the greater chemical energy.

Refer to the figure below.A biochemist inoculated a test tube containing liquid medium with a few bacterial cells of a single species.A concentration gradient of oxygen was present in the tube, with very low levels of oxygen at the bottom of the tube and increasingly higher concentrations toward the top of the tube.The highest levels of oxygen were at the top of the liquid medium.Glucose was present in equal concentrations throughout the tube. The particular bacterial species used to inoculate the tube is able to grow either aerobically or anaerobically.Which tube would most likely represent the growth pattern of bacteria under these conditions?

Refer to the figure showing the effects of four allosteric modifiers of the enzyme phosphofructokinase (PFK).Green arrows indicate allosteric activators, and red lines indicate allosteric inhibitors. Which statement correctly explains how one of these regulatory molecules functions to regulate flow of matter through the glycolytic pathway?

How could a carbon atom that was originally present in a glucose molecule end up in a purine base that becomes incorporated in a molecule of DNA?

Refer to the diagram below, showing energy-releasing metabolic pathways. Identify each numbered pathway.

Which event is not a part of oxidative phosphorylation?

The electron transport chain contains four large protein complexes (I, II, III, and IV) plus cytochrome c and ubiquinone.One function of these components is to

Carbon atoms originating in glucose are _______ oxidized after the citric acid cycle than they are after glycolysis.

Compare the amount of glucose consumption needed by an anaerobic fermenting microorganism with that needed by an aerobic organism in order to perform the same functions.The anaerobe would need much (more/less) _______ glucose than the aerobe.

When a cell needs energy, cellular respiration is regulated by isocitrate dehydrogenase, an enzyme of the citric acid cycle.This enzyme is stimulated in part by

Which reaction is not an example of an oxidation-reduction reaction?

Different organisms have different ATP yields from cellular respiration.Organisms with lower yields often have _______ systems that are energy consumptive but enable NADH produced by glycolysis to move into the mitochondria where it can enter oxidative phosphorylation.

The figure below illustrates one type of mechanism used by a cell to regulate its metabolism. This is an example of a(n) _______ mechanism of regulation.

Construct a diagram to explain how the free energy stored in the electrons present in NADH and FADH₂ is transferred to the terminal phosphate bond of ATP.

Humans can exist quite well on high-protein diets with very little carbohydrate.The body still maintains constant blood glucose levels even though very little glucose or other sugars come in through the diet.In this case, liver cells use pathways such as the citric acid cycle and gluconeogenesis to convert _______ from protein breakdown into glucose to maintain glucose levels in the blood.