Chapter 10 Review Quiz

Aerobic Metabolism II: Electron Transport and Oxidative Phosphorylation

. Obligate anaerobes have difficulty living in environments containing:

. The mechanism of damage done by free radicals (now called reactive oxygen species) to both physiological systems and to mechanical substances is still not fully understood, but the danger posed is substantial. ROSs are implicated in nasty processes from polymerization of gasoline to formation of varnishes which clog carburetors and injectors to formations of plaque which may cause arteries. Producers of foodstuffs worry about ROSs causing premature spoilage of foods, and often include free radical scavengers. Even some fitness waters contain free radical scavengers. Examine a box of cereal and find the antioxidant labeled there:

. During the terrible winter fighting conditions on the Eastern Front in Europe during WWII, many soldiers froze to death. In order to maintain higher body temperatures, some armies are reported to have been issued pills of 2,4-dinitrophenol. While use of this uncoupler of oxidative phosphorylation may have resulted in higher temperatures, it might have caused eventual organ failure. Which organ?

. Formation of ATP is increased by:

. If not otherwise dangerous, uncouplers would make good diet aids because:

. Formation of ATP as a result of passage of electrons through the ETC is sometimes called oxidative phosphorylation because:

. Long known to be protective against scurvy, Vitamin C owes at least some of its value to the fact that it acts as an antioxidant. This means that vitamin C itself is:

. Dentists often examine the mouths of patients for signs of acatalasemia. In this illness, hydrogen peroxide produced by bacteria may oxidize the Fe+2 of hemoglobin to Fe+3, forming methemoglobin which does not carry oxygen as well. Ordinarily, we are protected from this danger by the enzyme:

. Both cyanide ion and hydrogen cyanide gas are highly toxic, blocking the movement of electrons through the ETC. Victims of cyanide poisoning often display rictus, a gaping grimace as though they were trying to take a bite out of the air. One reason why they might do this is:

. Reactive oxygen species such as hydrogen peroxide and superoxide radicals may be generated by scavenger cells and used to destroy unwanted invaders or metabolic fragments. The ROS are generated by a process called the:

. Among the important antioxidant molecules taken in with our food are:

. The endoplasmic reticulum usually functions in an oxidative environment. In ER stress, low oxygen concentration results in inability of the ER to properly facilitate protein folding. Which of the following reactions is likely to be compromised?

. Persons who suffer angina (chest pain associated with cardiac problems) sometimes place a small pill containing nitroglycerine under their tongue. As the nitroglycerine decomposes, a small amount of a substance is produced which lowers blood pressure, relieving the angina. The substance released by decomposing nitroglycerine is an important signaling molecule which helps to regulate blood pressure. Which of the following is the best candidate?

. Erythrocytes are fragile and may be damaged by illnesses such as hemolytic anemia, resulting in dark-colored urine. Normally, the erythrocytes are protected by:

. While selenium may be an important part of some enzyme systems, large quantities can be toxic. Both Marco Polo in his historic travels to China and present-day ranchers in Western Nebraska and Eastern Wyoming suffered livestock losses due to toxic levels of selenium in plants eaten by the animals. One route of absorption of selenium might be its incorporation in amino acids in the plant, and later release of the selenium upon digestion and metabolism of the amino acids. Which amino acid might be a good candidate to carry the selenium?

. The interior of the inner mitochondrial membrane is relatively impermeable to ionic substances because:

. The ATP synthase complex is often called the F1Fo ATP synthase. This refers to the fact that the synthase enzyme is composed of:

. Glucose may be oxidized by a combination of several pathways and cycles. If the oxidation of glucose relied on glycolysis and the TCA cycle, how many moles of ATP could be produced by complete oxidation of a mole of glucose-6-phosphate?

. Depriving muscle tissue of oxygen is a dangerous process known as:

. A single reduced molecule or NADH is considered to be equivalent in energy to 2.5 ATP molecules. Oxidation of a mole of FADH2 yields 1.5 ATP. In chemical terms, this would mean that:

. Mitchell's chemiosmotic theory suggested that a high concentration of protons outside the mitochondrial membrane:

. It's likely that your cereal boxes note on their labels that the contents include a small amount of BHT or BHA (butylated hydroxyanisole). Both BHT and BHA are antioxidants included not to make you healthy, but to make you happier than you would be if the long chain fatty acids in your food become rancid. They become rancid by oxidative processes which attack double bonds in unsaturated acids. The result would be unpleasant because:

. Which is the correct order of decreasing size?

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