用的有机小分子。
汉译英
1. 所有的细胞都有细胞骨架，网络结构的纤丝充满了它所能触及的全部空间并且对细胞器提供支持作用。细胞骨架大部分由微
丝组成，微丝主要由可收缩的肌动蛋白组成。动植物细胞的许多种类型细胞内运动与肌动蛋白有关。
All eukaryotic cells have a cytoskeleton, which is a convoluted latticework of filaments and tubules that appears
to fill all available space in the cell and provides support for various other organelles. A large portion of the
cytoskeleton consists of threadlike microfilaments composed mainly of the contractile protein actin. They are
involved in many types of intracellular movements in plant and animal cells.
2. 第二类蛋白是肌球蛋白，它与肌肉细胞的收缩有关。细胞骨架的另一个主要结构成分是微管，由球状的微管蛋白组成，象脚
手架一般维持细胞的稳定形态。细胞骨架的中间丝提供了细胞质伸缩动力。机械酶，例如，肌球蛋白，动力蛋白，驱动蛋白与
微丝，微管相互作用产生动力而引起细胞运动。
A second protein, myosin, is involve in the contraction of muscle cells. Another main structural component of the
cytoskeleton consists of microtubules, which are composed of the globular protein tubulin and together act as
scaffolding that provides a stable cell shape. Cytoskeletal intermediate filaments appear to impart tensile strength
to the cell cytoplasm. Mechanoenzymes such as myosin, dynein, and kinesin interact with the cytoskeletal filaments
and tubules to generate forces that cause movements.
第三次作业
英译汉
1. Photosynthesis is a process used by plants and other organisms to capture the sun's energy to split off water's
hydrogen from oxygen. Hydrogen is combined with carbon dioxide (absorbed from air or water) to form glucose and
release oxygen. All living cells in turn use fuels derived from glucose and oxidize the hydrogen and carbon to release
the sun's energy and reform water and carbon dioxide in the process (cellular respiration).
英语辅导
光合作用是一个被植物体和其他有机生命体用来捕获太阳能将水中的氢与氧气分离的过程。氢与二氧化碳(从空气或水中吸收)
结合来形成葡萄糖并释放氧气。所有活细胞反过来使用由葡萄糖衍生的燃料以及氧化氢和碳来释放太阳能并同时在过程中生成
水和二氧化碳（细胞呼吸作用）。
2. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms
are called photoautotrophs, since they can create their own food. In plants and algae, photosynthesis uses carbon
dioxide and water, releasing oxygen as a waste product. Photosynthesis is vital for all aerobic life on Earth. In
addition to maintaining normal levels of oxygen in the atmosphere, photosynthesis is the source of energy for nearly
all life on earth, either directly, through primary production, or indirectly, as the ultimate source of the energy
in their food. 光合作用发生在植物、藻类和许多种细菌中,但不发生在古细菌中。能进行光合作用的生物体被称作光合自养生物,因为他们可
以生成他们自己的食物。在植物和藻类中，光合作用利用二氧化碳和水,释放氧气作为代谢产物。光合作用对地球上所有需氧的
生物至关重要。除了维持大气中氧气的正常水平,光合作用是地球上几乎所有生物的能量来源,无论是直接地,通过初级生产,或
间接地在他们的食物中作为最终能量来源。
汉译英
1. 光合作用只发生在含有叶绿素的绿色植物细胞，海藻，某些原生动物和细菌之中。总体来说，这是一个将光能转化成化学能，
并将能量贮存在分子键中，从化学和动能学角度来看，它是细胞呼吸作用的对立面。细胞呼吸作用是高度放能的，光合作用是
需要能量并高吸能的过程。
Photosynthesis occurs only in the chlorophyllchlorophyll叶绿素-containing cells of green plants, algae藻, and
certain protists 原生生物and bacteria. Overall, it is a process that converts light energy into chemical energy
that is stored in the molecular bonds. From the point of view of chemistry and energetics, it is the opposite of
cellular respiration. Whereas 然而 cellular细胞的 respiration 呼吸is highly exergonic吸收能量的 and releases
energy, photosynthesis光合作用 requires energy and is highly endergonic.
2. 光合作用以二氧化碳和水为原材料并经历两步化学反应。第一步，称光反应，水分子分解，氧分子释放，ATP和NADPH形成。
此反应需要光能的存在。第二步，称暗反应，二氧化碳被还原成碳水化合物，这步反应依赖电子载体NADPH以及第一步反应产
生的ATP。
Photosynthesis starts with CO2 and H2O as raw materials and proceeds through two sets of partial reactions. In the
first set, called the light-dependent reactions, water molecules are split裂开 (oxidized), 02 is released, and ATP
and NADPH are formed. These reactions must take place in the presence of 在面前 light energy. In the second set,
called light-independent reactions, CO2 is reduced (via the addition of H atoms) to carbohydrate. These chemical
events rely on the electron carrier NADPH and ATP generated by the first set of reactions.
第四次作业
英译汉
1. Mitosis and meiosis are similar processes in that they both result in the separation of existing cells into new