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Matter and energy cycling in ecosystems
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Lesson 1
Упражнение 1.
Прочитайте заголовок приводимого ниже текста. Подумайте, о чем в нем может идти речь. Приведите 10–15 слов, которые могут, с Вашей точки зрения, встретиться в тексте.
Прочитайте и переведите текст.
Carbon and Oxygen Cycles
Carbon is the basic building block of the large organic molecules necessary for life, including simple carbonhydrates or sugars (such as glucose), complex carbonhydrates, fats, proteins, and nucleic acids such as DNA. DNA molecules in the cells of plants and animals carry genetic information and chemical instructions for manufacturing various proteins living organisms need.
Most land plants obtain their carbon by absorbing carbon dioxide gas, which makes up 0,03% of the atmosphere, through pores in leaves. They obtain the oxygen atoms they need from the oxygen in carbon dioxide and from water molecules in soil or bodies of water. The ocean’s microscopic floating plants, known collectively as phytoplankton, get their carbon from atmospheric carbon dioxide that dissolved in ocean water.
Chlorophyll molecules and some other pigments in the cells of green plants absorb solar energy and use it to combine carbon dioxide with water to form glucose along with oxygen gas. This complex process in which radiant energy from the sun is converted into chemical energy stored in plant tissue is called photosynthesis.
Plants and animals transform a portion of glucose and other, more complex, carbon-containing molecules they synthesise (plants) or eat (consumers) back into carbon dioxide and water by the process of cellular respiration. The chemical energy released in this complex process drives the physical and chemical changes needed for plants and animals to survive, grow and reproduce.
The carbon dioxide released by cellular respiration in all plants and animals is returned to the atmosphere and water for reuse by producers. Although the overall chemical reaction involved in cellular respiration is the reverse of that for photosynthesis, many of the detailed chemical reactions involved in the processes are different.
Photosynthesis and respiration are the basis of carbon and oxygen cycles. Through these two interconnected cycles, plants produce food and oxygen needed by animals and absorb carbon dioxide given off by animals.
Some of the earth’s carbon is tied up for long periods in fossil fuels – coal, petroleum, natural gas, peat, oil shale, tar sands, and lignite – formed over millions of years in lithosphere. The carbon in these mineral deposits remains locked deed in the earth’s crust until it is released to the atmosphere as carbon dioxide when fossil fuels are extracted and burned. Some of the earth’s carbon is also locked for millions of years in deposits of carbonate rocks below the seafloor until movements of the earth’s crust expose these rocks as part of an island or a continent. The carbon then reenters the cycle very slowly through erosion and other physical and chemical weathering processes that release it as carbon dioxide into the atmosphere.
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Human beings intervene in the carbon and oxygen cycles in two ways that increase the average amount of carbon dioxide in the atmosphere. First, we remove forests and other vegetation without sufficient replanting, so that fewer plants are available worldwide to convert carbon dioxide in the atmosphere to organic nutrients. Second, we burn fossil fuels and wood.
Упражнение 2.
Прочитайте следующие слова и определите их соответствия
в русском языке:
Cycle, organic, molecule, nucleic, genetic, information, chemical, physical, organism, gas, atom, pore, ocean, atmospheric, microscopic, phytoplankton, pigment, form, glucose, energy, photosynthesis, transform, synthesise, complex, detailed, process, period, mineral, lithosphere, continent.
Упражнение 3.
Какие части речи обозначаются в словарях следующими сокращениями:
v., adv., n., adj., conj., num., part., prep., pron.?
Упражнение 4.
Определите, к каким частям речи относятся следующие слова; напишите соответствующие английские сокращения для каждого из них:
Animal, first, respiration, for, cellular, they, in, and, widely, is, extracted, million, remove.
Упражнение 5.
Найдите в тексте Carbon and Oxygen Cycles примеры этих частей речи.
| v. | n. | adj. | adv. | num. | prep. | part. |
Упражнение 6.
Заполните пропуски, используя суффиксы: ~able, ~al/~ial, ~ful, ~ic, ~ine, ~ish, ~ive, ~less.
Diamond is a form of pure … (crystal) carbon which has been formed under great heat and pressure and brought to the surface of the Earth by … (volcano) activity. It is the hardest … (nature) substance in the world with a very high … (refract) power giving specific … (optic) properties, above all, a particularly clear and brilliant reflection of light. The most … (value) diamonds are completely … (without colour) They are, however, extremely rare; the majority having a … (slightly yellow) or … (slightly green) colour caused by different mineral impurities and gases. Diamond feels cold to the touch as it dissipates heat very quickly, hence, checking thermal conductivity is a … (rely) method of detection. Cheaper synthetic diamonds are now being made for … (industry) applications. These are particularly … (use) for cutting tools.
Упражнение 7.
В правой колонке найдите русские эквиваленты следующих английских словосочетаний из текста Carbon and Oxygen Cycles:
| 1. carbon dioxide 2. living organism 3. plant tissues 4. radiant energy 5. cellular respiration 6. interconnected cycles 7. mineral deposits 8. fossil fuel 9. weathering process 10. average amount | a. ископаемое топливо b. процесс выветривания c. клеточное дыхание d. ткани растений e. углекислый газ f. среднее количество g. живой организм h. лучистая энергия i. взаимосвязанные циклы j. минеральные отложения |
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Упражнение 8.
Прочитайте текст и найдите в нем ответы на следующие вопросы:
1. От чего зависит важность того или иного элемента для живых организмов?
2. Что способствует круговороту элементов?
3. Что произошло бы без биогеохимических циклов?
(Контрольное время – 7 минут)
Biogeochemical Cycles
Of the earth’s 92 naturally occurring elements, only 20 to 30 are constituents of living organisms and thus are cycled through the biosphere. In chemical terms, life can almost be summed up in five words: carbon, oxygen, hydrogen, nitrogen, and phosphorus. These chemicals as elements and compounds make up 97% of the mass of your body and more than 95% of the mass of all living organisms.
The remaining 15 to 25 elements needed in some from for the survival and good health of plants and animals are required only in relatively small, or trace, amounts. The importance of a particular chemical to a living organism varies with the physical and chemical from and location of the chemical. For example, plants obtain most of their carbon in the form of carbon dioxide gas from the atmosphere or water, and most of their nitrogen and phosphorus as nitrate ions and phosphate ions from soil water in which containing these ions are dissolved.
Only a small portion of the earth’s chemicals exist in forms useful to plants and animals. Fortunately, the essentially fixed supply of elements and compounds needed for life is continuously cycled through the air, water, soil, plants, and animals and converted to useful forms in biogeochemical cycles (bio meaning “living”, geo for water, rocks, and soil, and chemical for the matter changing from one form to another). These cycles, driven directly or indirectly by incoming energy from the sun, include the carbon, oxygen, nitrogen, phosphorus, and hydrologic cycles.
Thus a chemical may be part of an organism at one moment and part of its nonliving environment at another moment. This means that one of the oxygen molecules you just inhaled may be one inhaled previously by you, your grandmother, King Tut thousands of years ago, or a dinosaur millions of years ago.
Similarly, some of the carbon atoms in the skin converting your right hand may once have been part of a leaf, a dinosaur hide, or a limestone rock. Without the biogeochemical cycles, the entire world would soon be knee-deep in plant litter, dead animal bodies, animal wastes, and garbage.
Упражнение 9.
Выберите из текста Biogeochemical Cycles 10–15 основных,
с точки зрения смысловой нагрузки, слов (ключевые слова). Определите, к каким частям речи они относятся.
Упражнение 10.
Переведите текст письменно. (Контрольное время – 30 минут)
Phosphorus Cycle
Phosphorus, mainly in the of phosphate ions, is an essential nutrient of both plants and animals. It is a major constituent of the genetic material coded in DNA molecules and the main component of bones and teeth. It is also used some commercial fertilizers.
Various form of phosphorus are cycled through the lower atmosphere, water, soil, and living organisms by the phosphorus cycle. The major reservoirs of phosphorus are phosphate rock deposits on land and in shallow ocean sediments. Some phosphates released by the slow breakdown of phosphate rock deposits are dissolved in soil water and taken up by plant roots. Animals get their phosphorus by eating plants or animals that have eaten plants. Animal wastes and the decay products of dead animals and plants return much of this phosphorus to the soil, rivers, and eventually to the ocean bottom as insoluble forms of phosphate rock. Large amounts of phosphate eroded from the land to the oceans each year by natural processes and human activities.
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People intervene in the phosphorus cycle in several ways. First, large quantities of phosphate rock are dug up, mostly from shallow ocean deposits, and used primarily to produce commercial fertilizers and detergents. Second, discharge from sewage treatment plants and runoff of commercial fertilizers can overload aquatic ecosystems with phosphate ions. As in the case of nitrate ions, an excessive supply can explosive growth of blue-green algae and other aquatic plants that can disrupt life in aquatic ecosystems.
Упражнение 11.
Составьте 5 общих вопросов к тексту Phosphorus Cycle.
Упражнение 12.
(Парная работа) Ответьте на вопросы, составленные в упражнении 11.
Lesson 2
Упражнение 1.
Попытайтесь вспомнить, что Вам известно о круговороте азота.
Подумайте и приведите 10–15 слов, которые могут встретиться в тексте.
Прочитайте и переведите текст.
Nitrogen Cycle
Living things need nitrogen to manufacture proteins. Thus the growth of many plants can be limited by a lack of nitrogen from the soil. Too little nitrogen can also cause malnutrition in people, because many of the body’s essential functions require nitrogen-containing molecules such as proteins, DNA, and some vitamins.
The nitrogen gas that makes up about 78% of the volume of the earth’s atmosphere is useless to most plants and animals. Fortunately, nitrogen gas is converted into water-soluble ionic compounds containing nitrate ions, which are taken up by plant roots as part of the nitrogen cycle. This nitrogen fixation – that is, the conversation of atmospheric nitrogen gas into forms useful to plants – is accomplished by (1) soil bacteria; (2) rhi-zobium bacteria living in small swellings; (3) blue-green algae in water and soil; (4) lightning which converts nitrogen gas and oxygen gas in the atmosphere to forms that return to the earth as nitrate ions in rainfall and other types of precipitation.
Plants convert nitrates obtained from soil water into large, nitrogen-containing molecules such as the proteins and nucleic acids necessary for life and good health. Animals get most of the proteins and other nitrogen-containing molecules they need by eating plants or other animals that have eaten plants. When plants and animals die, decomposers break down the nitrogen-containing molecules into ammonia gas and water-soluble salts containing ammonium ions. Other specialized groups of bacteria then convert these forms of nitrogen back into nitrate ions in the soil and into nitrogen gas, which is released to the atmosphere to begin the cycle again.
Human beings intervene in the nitrogen cycle in several important ways. First, large quantities of NO and NO2 are added to the atmosphere when fossil fuels are burned in power plants and vehicles. These oxides of nitrogen can react with other chemicals in the atmosphere under the influence of sunlight to form photochemical smog and nitric acid, a major component of acid deposition, commonly known as acid rain. Second, nitrogen gas and hydrogen gas are converted by an industrial process into ammonia gas, which is then converted to ammonium compounds used as commercial fertilizer. Third, mineral deposits of compounds containing nitrate ions are mined and used as commercial fertilizers. Fourth, excess nitrate ions are added to aquatic ecosystems via the runoff of animal wastes from livestock feedlots, the runoff of commercial nitrate fertilizers from cropland, and the discharge of untreated and treated municipal sewage. This excess supply of nitrate plant nutrients can stimulate extremely rapid growth of algae and other aquatic plants, which can deplete the water of dissolved oxygen gas and cause massive fish kills.
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Упражнение 2.
Составьте 5 специальных вопросов к тексту Nitrogen Cycle.
Упражнение 3.
(Парная работа) Ответьте на вопросы, составленные в упражнении 2.
Упражнение 4.
Выберите из текста Nitrogen Cycle 10–15 ключевых слов. Какие из Ваших предположений оправдались?
Упражнение 5.
Определите, к каким частям речи относятся выбранные Вами слова.
Упражнение 6.
Найдите в тексте Nitrogen Cycle примеры этих частей речи.
| v. | n. | adj. | adv. | prep. |
Упражнение 7.
Используя суффиксы, образуйте глаголы или существительные и заполните пропуски в предложениях: ~(at)ion, ~sion, ~ise.
Примеры: to vary – variation; to divide – division; character – to characterise.
| Verbs | Nouns |
| 1. It is cheaper to regulate the temperature automatically. 2. If gases … very rapidly cryogenic temperatures are attained. 3. The committee was set up to standardise civil aviation procedures. 4. People get old because the body … genetic damage. 5. The first atomic bomb exploded on August 6, 1945. 6. The astronauts are provided with a 14-day supply of pressurised oxygen. 7. Solar energy is … from hydrogen. 8. Heat losses can be … by thermal protection. 9. It was necessary to extend the research facilities | Automatic temperature.... is more economical. Rapid expansion of the gases produces temperatures of below 120 Kelvin. His job involves the … of aviation safety procedures. Ageing is a result of the accumulationof genetic damage. 80,000 people were killed in the Hiroshima … The oxygen supply is stored under … The generation of solar energy involves the conversion of hydrogen. Efficient insulation reduces heat losses to a minimum. Because of the increase in staff, an … had to be built |
Упражнение 8.
В тексте Nitrogen Cycle найдите слова с суффиксами ~(at)ion, ~sion, ~ise.
Упражнение 9.
В правой колонке найдите русские эквиваленты следующих английских словосочетаний:
| 1. lack of nitrogen 2. essential functions 3. make up 4. plant roots 5. rapid growth 6. blue-green algae 7. nucleic acids 8. water-soluble salts 9. power plants 10. nitric acid 11. photochemical smog 12. commercial fertilizers 13. municipal sewage | a. растворимые в воде соли b. быстрый рост c. азотная кислота d. сине-зеленые водоросли e. жизненно важные функции f. электростанции g. городские сточные воды h. фотохимический смог i. промышленные (химические) удобрения j. корни растений k. составлять l. недостаток азота m. нуклеиновые кислоты |
Упражнение 10.
Слова, которые встретятся в тексте:
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conventional removal – стандартное удаление;
reside in – возлагаться;
replenish – наполнять.
Прочитайте текст. (Контрольное время – 5 минут)
Nitrification is the biological oxidation of ammonia with oxygen into nitrite followed by the oxidation of these nitrites into nitrates. Degradation of ammonia to nitrite is usually the rate limiting step of nitrification. Nitrification is an important step in the nitrogen cycle in soil. This process was discovered by the Russian microbiologist, Sergei Winogradsky.
Nitrifying organisms are chemoautotrophs, and use carbon dioxide as their carbon source for growth.
Nitrification also plays an important role in the removal of nitrogen from municipal wastewater. The conventional removal is nitrification, followed by denitrification. The cost of this process resides mainly in aeration (bringing oxygen in the reactor) and the addition of an external carbon source (e.g. methanol) for the denitrification.
Together with ammonification, nitrification forms a mineralisation process which refers to the complete decomposition of organic material, with the release of available nitrogen compounds. This replenishes the nitrogen cycle.
Упражнение 11.
Ответьте на следующие вопросы, исходя из информации
в тексте из упражнения 10:
1. Что такое нитрификация?
2. Где нитрификация играет важную роль?
3. За что отвечает процесс минерализации?
Упражнение 12.
Выпишите 10 ключевых слов из текста в упражнении 10.
Упражнение 13.
Найдите в тексте упражнения 10 слова с суффиксами ~(at)ion, ~sion, ~ise и переведите их.
Упражнение 14.
Письменно переведите текст. (Контрольное время – 25 минут)
Wastewater
Onsite sewage facilities such as septic tanks and holding tanks release large amounts of nitrogen into the environment by discharging through a drainfield into the ground. Microbial activity consumes the nitrogen and other contaminants in the wastewater. However, in certain areas the soil is unsuitable to handle some or all of the wastewater, and as a result, the wastewater with the contaminants enters the aquifers. These contaminants accumulate and eventually end up in drinking water. One of the contaminants concerned about the most is nitrogen in the form of nitrates. A nitrate concentration of 10 ppm or 10 milligrams per liter is the current EPA (Environmental Protection Agency) limit for drinking water and typical household wastewater can produce a range of 20-85 ppm (milligrams per liter).
Lesson 3
Упражнение 1.
Ниже приводятся первые предложения 6 абзацев текста. Какие выводы Вы можете сделать о содержании текста?
The source of the radiant energy that sustains all life on earth is the sun.
The sun is a gigantic gaseous fireball composed mostly of hydrogen and helium gases.
Each type of radiant or electromagnetic radiation can be viewed as a wave.
About 34% of incoming solar radiation is reflected back to space.
Most of the incoming radiation not reflected away is degraded into longer-wavelength heat.
Concern is growing that human activities affect global climate patterns…
Упражнение 2.
Прочитайте и переведите текст. Проверьте правильность Ваших предположений.
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