Below are the quiz questions for this module. A programmer should create a database of questions matched with answers. When a user enters this mode, they should be presented with an option to be asked a question. This should prompt a random question from the database and a button offering an answer, which appears when pressed. This then cycles over again until the user clicks an exit button.

Category - Definitions

Query - What definition best describes the term below?

Reversal

Category - Term Recognition

Query - What term does the description below refer to?

(Terms are shown on left, descriptions in middle, figures on right)

2,4-Dinitrophenol (DNP) | A chemical which permeabilizes the inner mitochondrial membrane to protons and uncouples oxidative phosphorylation from electron transport. Another such chemical is FCCP. |
Amytal | Barbiturate drug that inhibits electron transport by blocking electron flow between NADH and coenzyme Q. | Figure 15.9
Anaerobic | Refers to the absence of oxygen or the absence of a need for it. |
Antimycin A | A Streptomyces antibiotic that inhibits electron transport by blocking electron flow from cytochrome b to c1. | Figure 15.9
Antioxidants | Compounds that help prevent oxidative damage by scavenging oxygen radicals or by chemically reducing oxidized compounds. |
Antiport | A transport system that moves two molecules in opposite directions across a membrane. |
ATP |  | Figure 15.1
ATP Synthase Complex | Another name for Complex V | Figure 15.14
Azide | An inhibitor of electron transport that works by inhibiting cytochrome oxidase (Complex IV). This compound reacts with the oxidized form of the complex. | Figure 15.9
Carbon Monoxide | An inhibitor of electron transport that works by inhibiting cytochrome oxidase (Complex IV). This compound reacts with the reduced form of the complex. | Figure 15.9
Chemiosmotic Coupling | Widely accepted model, originally proposed by Peter Mitchell, that explains the synthesis of ATP in oxidative phosphorylation. |
Citric Acid Cycle | Major cyclic oxidative pathway by which acetyl-CoA is metabolized. | Figure 15.1
Coenzyme Q (ubiquinone or CoQ) | Electron acceptor from Complexes I and II of the respiratory chain. It donates electrons to Complex III. | Figure 15.3
Coupling | A phenomenon where two processes are linked with one another such that they are interdependent. |
Cristae | Infoldings of the mitochondrial inner membrane that project inside of the mitochondrion. |
Crossover Point | The place in an electron transport system where a respiratory inhibitor has blocked electron flow. Electron carriers before the block are reduced and carriers after the block are oxidized. |
Cyanide | An inhibitor of electron transport that works by inhibiting cytochrome oxidase (Complex IV). This compound reacts with the oxidized form of the complex. | Figure 15.9
Cytochrome Oxidase | A multiprotein complex containing cytochromes a and a3 of Complex IV. | Figure 15.10
Cytochromes | A group of red - brown heme proteins in the respiratory chain. |
Difference Spectra | Laboratory technique that exploits differences in the absorption spectra of oxidized and reduced electron carriers to detemine the oxidation state of each. | Figure 15.8
Dihydroxyacetone Phosphate/Glycerol-3-phosphate Shuttle | A system for transporting electrons from NADH to the electron transport system. It is found in brain and insect flight muscle. | Figure 15.11
Electrochemical Gradient | A gradient of electrical charge brought about by uneven distribution of charge. The mitochondria have such a gradient as a result of proton pumping. Also called Proton Motive Force (pmf). | Figure 15.15 | Electron Acceptor | In reactions involving oxidation and reduction, the molecule which is reduced. |  | Electron Donor | In reactions involving oxidation and reduction, the molecule which is oxidized. |
Electron Transport Chain | A set of proteins and other electron-carrying molecules in the inner membrane of the mitochondrion |
Endergonic | In a nonisolated system, a process that is accompanied by a positive change in free energy (positive G) and therefore is thermodynamically not favored. |
Exergonic | In a nonisolated system, a process that is accompanied by a negative change in free energy (negative G) and therefore is thermodynamically favored. |
F0F1 Complex | ATP Synthase Complex, also known as Complex V. | Figure 15.14)
F1 Spheres | Knoblike structures on the surface of the cristae of mitochondria that are part of Complex V |
FAD | Flavin molecule capable of carrying electrons produced in biological oxidations. | Figure 15.1
FADH2 | Flavin molecule that carries electrons. | Figure 15.1
FMN | Prosthetic group of NADH Dehydrogenase. |
Glutathione | A biological antioxidant that chemically reduces oxidized sulfurs in proteins. It also helps reduce peroxides. |
Heme A | A modified type of heme found in cytochromes a and a3. | Figure 15.6
Ionophore | A molecule that permits movement of charged molecules across a membrane |
Iron-Sulfur Centers | Electron carrying groups within the iron-sulfur proteins. They consist of nonheme iron complexed to sulfur. | Figure 15.4
Iron-Sulfur Proteins | Electron carrying proteins in the respiratory chain that contain iron-sulfur centers. | Figure 15.3
Mitochondrial Inner Membrane | Distinct mitochondrial structure that is not freely permeable to most metabolites. It contains the complexes of the electron transport system. | Figure 15.2
Mitochondrial Intermembrane Space | Region located between the inner and outer mitochondrial membranes. | Figure 15.2
Mitochondrial Matrix | Free space within the mitochondria bounded by the cristae. Contains enzymes of the citric acid cycle, fatty acid oxidation, amino acid oxidation, and pyruvate oxidation. | Figure 15.2
Mitochondrial Outer Membrane | Distinct structure surrounding mitochondria that is fairly permeable to most biological metabolites | Figure 15.2
NAD+ | The oxidized form of NADH. It is a common acceptor of electrons produced in biological oxidations. | Figure 15.1
NADH | The reduced form of NAD+, produced by transfer of electrons in biological oxidation. It can either donate electrons and reduce another biological molecule or can transfer electrons to the electron transport system. | Figure 15.1
NADH Dehydrogenase | Another name for Complex I |
Nernst equation | An equation that relates the electrical potential across a membrane to the concentrations of ions on either side of the membrane. |
Nigericin | An antibiotic that acts as a potassium/proton antiport. |
Oligomycin | An inhibitor of oxidative phosphorylation that acts by binding to a specific protein in the F0 complex. |
Oxidation | A process involving the loss of electrons by a molecule. Accompanies a reduction. |
Oxidized Electron Carrier | An electron carrier that has lost its electrons, such as NAD+, NADP+, or FAD. |
P/O Ratio | Quantity of ATP synthesized per mole of substrate oxidized in isolated mitochondria. |
Perferryl Ion | A highly reactive iron-oxygen intermediate generated as a result of P-450 action. The highly reactive group can abstract a hydrogen atom, even from an unreactive substrate, such as a hydrocarbon. | Figure 15.25
Phagocytosis | A defense mechanism of white blood cells against infectious agents using hydrogen peroxide and superoxides to kill the invading cells after they have been engulfed. |
Proton Gradient | Produced by"pumping" of protons during movement of electrons through the complexes of the electron transport system. It is the energy source used in oxidative phosphorylation to make ATP. | Figure 15.2
Protoporphyrin IX | Chemical form of the iron complexing moiety in the cytochrome proteins. |
Redox | A termed used as a shorthand designation of reduction-oxidation. |
Reduced Electron Carrier | An electron carrier that is carrying electrons, such as NADH, NADPH, or FADH2. |
Reducing Equivalent | An amount of a reducing compound that donates the equivalent of 1 mole of electrons in an oxidation-reduction reaction. The electrons may be expressed in the form of hydrogen atoms. |
Reduction | A process involving the gain of electrons by a molecule. Accompanies an oxidation. |
Respiration (Cellular) | With respect to energy metabolism, the process in which cellular energy is generated through the oxidation of nutrient molecules with O2 as the ultimate electron acceptor. |
Respiratory Burst | A rapid intake of oxygen by white blood cells upon engulfing an invading bacterial cell. The oxygen is used to generate hydrogen peroxide and superoxide dismutase to kill the invader. |
Respiratory chain | The set of five multiprotein complexes, (named I, II, III, IV, V), coenzyme Q, and cytochrome c that make up the electron transport system and oxidative phosphorylation. | Figure 15.2b
Respiratory Control | A phenomenon that results from tight coupling of oxidative phosphorylation and electron transport. Events that stop one of the processes, stop the other as well. |
Rotenone | An inhibitor of electron transport that blocks electron flow between NADH and coenzyme Q. | Figure 15.9
Semiquinone | Chemical intermediate form of coenzyme Q during passage of electrons. |
Standard Reduction Potential (E0) | A measure of the tendency of a reductant to lose electrons. | Table 15.1
Succinate-coenzymeQ Reductase | Another name for Complex II of the respiratory chain. |
Superoxide Ion | A reactive species generated as a result of a one electron reduction of O2, to form O2-. |
Tetramethyl-p-phenylene diamine (TMPD) | An artificial donor of electrons to the electron transport system. It accepts electrons from ascorbate and donates them to cytochrome c. |
Transhydrogenase | An enzyme catalyzing transfer of electrons between NADPH and NAD+: NADPH + NAD+ <=> NADP+ + NADH |
Trifluorocarbonylcyanide phenylhydrazone (FCCP). | A chemical which permeabilizes the inner mitochondrial membrane to protons and uncouples oxidative phosphorylation from electron transport. Another such chemical is DNP. |
Valinomycin | An ionophore that transports potassium ions. |
Xenobiotics | Substances recognized by the body as foreign. They are frequently subjected to hydroxylation by P-450 proteins. |
Pyruvate Dehydrogenase | Enzyme catalyzing oxidation of pyruvate to acetyl-CoA - Pyruvate + NAD+ + Coenzyme A <=> Acetyl-CoA + NADH + CO2. |
Adenine Nucleotide Translocase | An inner mitochondrial transport protein that spans the inner membrane and binds to ADP at a specific site. It couples movement of ATP out of the matrix as it moves ADP in. |
Phosphate Translocase | An inner mitochondrial transport protein that acts as either an antiport or a symport. As an antiport, it transports H2PO4- into the matrix coupled with movement of hydroxide out. As a symport, it transports H2PO4- in to the matrix together with two protons. |
Oxidase | An enzyme that catalyzes the oxidation of a substrate without incorporation of oxygen from O2 into the product. |
D-amino acid oxidases | Enzymes that catalyze reaction of the general form as: D-amino acid +H2O + FAD -> -keto acid + Ammonium ion + FADH2. Then FADH2 + O2 -> FAD + H2O2. |
Oxygenases | General name for enzymes that incorporate oxygen from O2 into the oxidized products. |
Dioxygenases | Oxygenases that incorporate both atoms from O2 into one substrate. An example is tryptophan 2,3-dioxygenase. |
Cytochrome P-450 | A family of heme proteins usually found in the endoplasmic reticulum of eukaryotic cells that are involved in hydroxylating a large variety of compounds, including steroid hormones and the synthesis of hydroxylated fatty acids and fatty acid epoxides. |
Peroxidases | A family of enzymes that reduce hydrogen peroxide to water at the expense of an organic substrate. |

Glycolysis | Central metabolic pathway of carbohydrate metabolism. | Figure 15.1

Category - General

Query - Is contained in the left column below, solution in middle, figure on right

Reversal - there is no reversal

What is the molecule to which electrons from NADH are donated in the Dihydroxyacetone Phosphate/Glycerol-3-phosphate Shuttle? | FAD, to make FADH2. |  | What are the two molecules that cross the outer mitochondrial membrane of the Dihydroxyacetone Phosphate/Glycerol-3-phosphate Shuttle? | Glycerol-3-phosphate and Dihydroxyacetone Phosphate |  | How many ATPs can be generated per NADH when the Dihydroxyacetone Phosphate/Glycerol-3-phosphate Shuttle is used to transfer electrons to the electron transport system? | Two |  | How many ATPs can be generated per NADH when the Malate-Aspartate Shuttle is used to transfer electrons to the electron transport system? | Three |  | What molecules cross the inner mitochondrial membrane in the malate-aspartate shuttle? | Glutamate, aspartate, -ketoglutarate, malate |  | In the malate-aspartate shuttle, malate is oxidized to what molecule as it donates electrons to NAD+? | Oxaloacetate |  | Which of the respiratory complexes pump protons during electron transport? | Complexes I, III, IV |  | What is the P/O ratio of NADH when the malate-aspartate shuttle is used? | Three |  | What is the P/O ratio of NADH when the Dihydroxyacetone Phosphate/Glycerol-3-phosphate Shuttle is used? | Two |  | What is the P/O ratio of FADH2? | Two |  | What is the cofactor present in Tryptophan 2,3-dioxygenase? | Heme |  | Why do organisms sometimes uncouple oxidative phosphorylation from electron transport? | To generate heat. |  | Why do many enzymes that act on oxygen have bound metal ions? | To enhance the reactivity of oxygen. |  | How many enzymes use O2 as a substrate? | Over 200 |  | How many electrons are typically involved in oxidase-catalyzed oxidation reactions? | Two |  | What are common cofactors of oxidases? | Flavin coenzymes or metals |  | List reactions catalyzed by P-450 enzymes | Hydroxylations, epoxidations, peroxygenations, desulfurations, dealkylations, deaminations, dehalogenations. |  | What unusual amino acid is found in glutathione peroxidase? | Selenocysteine |  | Where are superoxides and hydrogen peroxide used as a defense mechanism by cells? | In phagocytosis, where white blood cells engulf the invading cells and use these agents to kill them. |  | Explain 4 Principles of the Chemiosmotic Coupling Hypothesis | 1. Transport of electrons by the electron transport system causes protons to be moved from inside the mitochondrion to the outside, creating a proton gradient. |  | 2. In mitochondria with an intact inner membrane, the proton gradient is the source of energy for ATP synthesis |  | 3. ATP is synthesized as protons pass through Complex V. |  | 4. Agents which make the inner mitochondrial membrane permeable to protons uncouple electron transport from oxidative phosphorylation. |  | Give four pieces of evidence in support of the chemiosmotic hypothesis | 1. An intact inner membrane is required for oxidative phosphorylation. |  | 2. Key electron transport proteins span the inner membrane |  | 3. Uncoupling agents, such as 2,4-dinitrophenol or trifluorocarbonylcyanide phenylhydrazone (FCCP), act by dissipating the proton gradient. |  | 4. Generation of a proton gradient permits ATP synthesis without electron transport. |  | Name a biological system where uncoupling of electron tranport and oxidative phosphorylation is employed. | 1. Brown fat |  | 2. Floral spike of the skunk cabbage. |  | List 3 reactive species generated as a result of incomplete reduction of molecular oxygen (O2). | 1. Superoxide (O2-) |  | 2. H2O 2 |  | 3. Hydroxyl radical |  | List three altered nucleotide bases produced by hydroxyl radical interaction with DNA | 1. 8-Hydroxyguanine |  | 2. Thymine Glycol |  | 3. 5-Hydroxymethyluracil |  | List 4 compounds that act as biological antioxidants | 1. Glutathione |  | 2. L-Ascorbic Acid (Vitamin C) |  | 3. Uric Acid |  | 4. -tocopherol (Vitamin E) |  | What are the names of the three sites on the F1 complex where ATP, ADP, and Pi are bound in ATP synthesis? | L = Loose binding site. ADP and Pi bind here. |  | T = Tight binding site. ATP is held here and ATP is formed here from ADP + Pi. |  | O = Open binding site. ATP is released from here. |

Category - Enzymes

Query - What enzyme catalyzes this reaction?

Reversal

Category - Reactions

Query - What catalytic activity does the enzyme below have?

(enzyme on left, reaction in center, figure on right)

Superoxide dismutase | O2- + O2- + 2H+-> H2O2 + O2 |  | Catalase | 2H2O2 ->2H2O + O2 |

Tryptophan 2,3-dioxygenase | Tryptophan + O2 -> N-Formylkynurenine |

Transhydrogenase | NADPH + NAD+ <=> NADP+ + NADH |

Pyruvate Dehydrogenase | Pyruvate + NAD+ + Coenzyme A <=> Acetyl-CoA + NADH + CO2. |  | D-Amino acid oxidases | Enzymes that catalyze reaction of the general form as: D-amino acid +H2O + FAD -> -keto acid + Ammonium ion + FADH2. Then FADH2 + O2 -> FAD + H2O2. |