教学内容：
Cytoplasm: The Dynamic, Mobile Factory
细胞质：动力工厂
Most of the properties we associate with life are properties of the cytoplasm. Much of the
mass of a cell consists of this semifluid substance, which is bounded on the outside by the
plasma membrane. Organelles are suspended within it, supported by the filamentous network
of the cytoskeleton. Dissolved in the cytoplasmic fluid are nutrients, ions, soluble proteins,
and other materials needed for cell functioning.
生命的大部分特征表现在细胞质的特征上。细胞质大部分由半流体物质组成，并由细胞膜（原生质膜）包被。细胞器悬浮在其中，并由丝状的细胞骨架支撑。细胞质中溶解了大量
的营养物质，离子，可溶蛋白以及维持细胞生理需求的其它物质。
The Nucleus: Information Central（细胞核：信息中心）
The eukaryotic cell nucleus is the largest organelle and houses the genetic material (DNA) on chromosomes. (In prokaryotes the hereditary material is found in the nucleoid.) The nucleus
also contains one or two organelles-the nucleoli-that play a role in cell division. A
pore-perforated sac called the nuclear envelope separates the nucleus and its contents from the cytoplasm. Small molecules can pass through the nuclear envelope, but larger molecules such
as mRNA and ribosomes must enter and exit via the pores.
真核细胞的细胞核是最大的细胞器，细胞核对染色体组有保护作用（原核细胞的遗传物质
存在于拟核中）。细胞核含有一或二个核仁，核仁促进细胞分裂。核膜贯穿许多小孔，小
分子可以自由通过核膜，而象mRNA和核糖体等大分子必须通过核孔运输。
Organelles: Specialized Work Units（细胞器：特殊的功能单位）
All eukaryotic cells contain most of the various kinds of organelles, and each organelle
performs a specialized function in the cell. Organelles described in this section include ribosomes, the endoplasmic reticulum, the Golgi complex, vacuoles, lysosomes, mitochondria,
and the plastids of plant cells.
所有的真核细胞都含有多种细胞器，每个细胞器都有其特定功能。本节主要介绍核糖体，
内质网，高尔基体系，液泡，溶酶体，线粒体和植物细胞中的质体。
The number of ribosomes within a cell may range from a few hundred to many thousands.
This quantity reflects the fact that, ribosomes are the sites at which amino acids are assembled
into proteins for export or for use in cell processes. A complete ribosome is composed of one larger and one smaller subunit. During protein synthesis the two subunits move along a strand
of mRNA, "reading" the genetic sequence coded in it and translating that sequence into protein. Several ribosomes may become attached to a single mRNA strand; such a combination is called
a polysome. Most cellular proteins are manufactured on ribosomes in the cytoplasm.
Exportable proteins and membrane proteins are usually made in association with the endoplasmic reticulum.
核糖体的数量变化从几百到几千，核糖体是氨基酸组装成蛋白质的重要场所。完整的核
糖体由大亚基和小亚基组成。核糖体沿着mRNA移动并阅读遗传密码，翻译成蛋白质。一条mRNA上可能有多个核糖体，称多聚核糖体。大多数细胞蛋白是由细胞质中核糖体生产。输出蛋白和膜蛋白通常与内质网有关。
The endoplasmic reticulum, a lacy array of membranous sacs, tubules, and vesicles, may be
either rough (RER) or smooth (SER). Both types play roles in the synthesis and transport of proteins. The RER, which is studded with polysomes, also seems to be the source of the
nuclear envelope after a cell divides.
内质网，带有花边的生物囊，有管状，泡状之分，以及光滑和粗糙面区别。两种都与蛋
白质的合成和运输有关。粗糙内质网上分布许多核糖体，也可能提供细胞分裂后所需的细胞膜。
SER lacks polysomes; it is active in the synthesis of fats and steroids and in the oxidation of toxic substances in the cell. Both types of endoplasmic reticulum serve as compartments
within the cell where specific products can be isolated and subsequently shunted to particular areas in or outside the cell.
光滑内质网上无核糖体，主要作用是脂肪和类固醇的合成以及细胞内有毒物质的氧化。
两种内质网合成的产物在其中进行分流或运输到细胞外。
Transport vesicles may carry exportable molecules from the endoplasmic reticulum to another membranous organelle, the Golgi complex. Within the Golgi complex molecules are modified and packaged for export out of the cell or for delivery else where in the cytoplasm.
运输小泡能够将可运输分子从内质网运输到高尔基复合体上。在高尔基复合体中修饰，
包装后输出细胞或传递到细胞质中的其他场所。
V acuoles in cells appear to be hollow sacs but are actually filled with fluid and soluble molecules. The most prominent vacuoles appear in plant cells and serve as water reservoirs
and storage sites for sugars and other molecules. V acuoles in animal cells carry out phagocytosis (the intake of particulate matter) and pinocytosis (vacuolar drinking).
细胞中的液泡好象是中空的，但实际上充满了液体和可溶分子。最典型的液泡存在于植
物细胞中，储备水，糖以及其它分子。动物中的液泡起吞噬和胞饮作用。
A subset of vacuoles are the organelles known as lysosomes, which contain digestive
enzymes (packaged in lysosomes in the Golgi complex) that can break down most biological macromolecules. They act to digest food particles and to degrade damaged cell parts.
溶酶体是液泡亚单位，含有消化酶，降解大部分生物大分子。消化食物微粒和降解损伤
的细胞残片。
Mitochondria are the sites of energy-yielding chemical reactions in all cells. In addition,
plant cells contain plastids that utilize light energy to manufacture carbohydrates in the process of photosynthesis. It is on the large surface area provided by the inner cristae of mitochondria that A TP-generating enzymes are located. Mitochondria are self-replicating, and probably they are the evolutionary descendants of what were once free-living prokaryotes.
线粒体是细胞中化学产能的场所。另外，植物细胞中的质体在光合作用中利用光能产生
碳水化合物，线粒体内嵴上提供了很大的表面积并分布着产A TP酶。线粒体自我复制，并且可能是自由生活的原核生物在进化中形成的后代。
There are two types of plastids: leucoplasts, which lack pigments and serve as storage sites
for starch, proteins, and oils; and chromoplasts, which contain pigments. The most important chromoplasts are chloroplasts-organelles that contain the chlorophyll used in photosynthesis. The internal structure of chloroplasts includes stacks of membranes called grana, which are embedded in a matrix called the stroma.
质体有两种类型：白色体，缺乏色素，是淀粉，蛋白质和油的储备场所；色质体，含有
色素。叶绿体是最重要的色质体，含有与光合作用有关的叶绿素。叶绿体的内部结构是由多层膜形成的叶绿体基粒，其中包埋在基质中的基粒称子座。
The Cytoskeleton（细胞骨架）
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. 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.
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。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。
Cellular Movements（细胞运动）
Although the cytoskeleton provides some stability to cells, its microtubules and filaments and their associated proteins enable cells to move by creeping or gliding. Such movements require
a solid substrate to which the cell can adhere and can be guided by the geometry of the surface. Some cells also exhibit chemotaxis, the ability to move toward or away from the source of a diffusing chemical.
尽管细胞骨架提供了细胞的某些稳定性，微丝，微管及相关蛋白能使细胞爬行或滑动。
这种运动需要固体基质依托并通过表面几何形状的改变而运动。某些细胞具备趋药性，即趋向或逃离扩散开的化学源。
Certain eukaryotic cells can swim freely in liquid environments, propelled by whiplike cilia
or flagella. Both cilia and flagella have the same internal structure: nine doublets (pairs of microtubules) are arranged in a ring and extend the length of the cilium or flagellum, and two more microtubules run down the center of the ring. Every cilium or flagellum grows only from
the cell surface where a basal body is located. Movement is based on the activities of tiny
dynein side arms that extend from one of the microtubules of each doublet.
某些真核细胞能在液体液体中自由运动，由纤毛或鞭毛推动。纤毛和鞭毛具有同样的内
部结构：九个双微管环形排列，纵向延伸，环中心是两个或以上微管组成。纤毛或鞭毛从细胞表面的基体出生长，双微管的动力蛋白臂从一侧延伸到另一侧而引起运动。Nutrients, proteins, and other materials within most plant cells are moved about via
cytoplasmic streaming. The process occurs as myosin proteins attached to organelles push against microfilaments arrayed throughout the cell. Microfilaments and microtubules are responsible for almost all major cytoplasmic movements. During cell division, microtubules of
the spindle assembled from tubutin subunits near organelles called centrioles move the chromosomes.
大部分植物细胞的营养，蛋白质和其它物质由细胞质流运输。这个过程是由于依附在细
胞器上的肌球蛋白反推排列在细胞周围的微丝形成的。绝大部分细胞质运动由微丝和微管完成。在细胞分裂期间，中心粒周围的由微管蛋白亚基装配形成的纺锤体微管移向染色体。课后作业：第一第二篇阅读材料
答案：1B,2C,3B,4B,5D,6c; 1A,2B,3D,4A Glossary
cytoplasm （细）胞质
The living contents of a cell bounded externally by the plasmalemma, including an aqueous ground substance (hyaloplasm, cell sap, or cell matrix) containing organelles and various inclusions but excluding the nucleus and visible vacuoles.
cytoskeleton 细胞骨架
Of eukaryotic cells, an internal "skeleton". Its microtubules and other components structurally support the cell, organize and move its inteftial components. The cytoskeleton also helps free-living cells move through their environment.
nucleus 细胞核，核(复数
nuclei)
The organelle of the eukaryote cell that contains the chromosomes and hence ultimately controls cellular activity and inheritance through the activity of the genetic material, DNA
chromosome 染色体
A DNA-histone thread residing in the nucleus of a cell. Each chromosome possesses two telomeres and a centromere, and some contain a nucleolus organizer. RNA proteins are invariably associated with the chromosome.
nucleoid 拟核，类核，核质体
The DNA-containing area of a prokaryote cell, analogous to the eukaryote nucleus but not membrane bounded.
nucleoli 核仁( 单数
nucleolus)
Nuclear structures composed of completed or partially completed ribosomes and the specific parts of chromosomes that contain the infon-nation for their construction. nuclear envelope 核膜，核被膜
A double membrane (two lipid bilayers and associated proteins) that is the outermost portion of a cell nucleus.
ribosome 核糖体
Small structures composed of two protein and ribonucleic acid subunits involved in the assembly of proteins from amino acids. polysome 多核糖体
Of protein synthesis, several ribosomes all translating the same messenger RNA molecule,one after the other.
endoplasmic reticulum 内质网
Folded membranes and tubes throughout the eukaryotic cell that provide a large surface upon which chemical activities take place. Golgi complex 高尔基复合体
A stack of flattened, smooth, membranous sacs; the site of synthesis and packaging of certain molecules in eukaryotic cells. vacuole 液泡
Storage container within the cytoplasm of a cell having a surrounding membrane. phagocytosis 吞噬作用
The process by which the cell wraps around a particle and engulfs it.
pinocytosis 胞饮作用
The process by which a cell engulfs some molecules dissolved in water
lysosome 溶酶体
A specialized organelle that holds a mixture of hydrolytic enzymes.
mitochondrion 线粒体(复数mitochondria )A membranous organelle resembling a small bag with a larger bag resembling a small bag with a larger bag inside that is folded back on itself; serves as the site of aerobic cellular respiration. plastid 质体
An organelle present in all plants except bacteria, blue-green algae, and fungi; it is enclosed by two membranes (the envelope) and has various functions
chloroplast 叶绿体
A plastid in which photosynthesis is carried out. Chloroplasts occur in all photosynthetic organisms except photosynthetic bacteria blue-green algae.
stroma 基质，子座（复数
stromata）
Region within a chloroplast that has no chlorophyll.
microfilament 微丝，纤丝
Long, fiberlike structures made of protein and found in cells, often in close association with the microtubules; provide structural support and enable movement.
actin 肌动蛋白
A globular contractile protein. In muscle cells, actin interacts with another protein, myosin, to bring about contraction.
myosin ['maiesin] 肌球蛋白
A protein that, with actin, constitutes the principal element of the contractile apparatus of muscle.
microtubute 微管
Small, hollow tubes of protein that function throughout the cytoplasm to provide structural support and enable movement. tubulin 微管蛋白
A protein that is the major constituent of microtubules.
dynein 动力蛋白，动素
A group of at least four distinct proteins found in the flagella and microtubules of eukaryotic cells and possessing A TPase activity.
chemotaxis 趋化性
A locomotory movement of an organism or cell in response to, and directed by, an directional stimulus.
cilia 纤毛
Numerous short, hairlike structures projecting from the cell surface that enable locomotion. flagella 鞭毛(单数flagellum)
Long, hairlike structures projecting from the cell surface that enable locomotion.
basal body 基体
A body identical in structure to a centriole, found always at the base of a
cilium or eukaryote flagellum.
centriole 中心粒
An organelle located close to the nucleus in
most animal and lower plant cells but absent
from prokaryotes and higher plants.
Lesson Two（2学时）
Photosynthesis
教学目的：使学生掌握细胞的光合作用机理，光合系统Ⅰ与光合系统Ⅱ结构与
功能之间的关系。相关英语词汇以及主要用法。
教学重点：光合作用中相关的概念和功能，及相关英语词汇的掌握
教学难点：专业英语词汇的记忆
讲授方法：以学生翻译为主，老师讲解相关专业知识辅助学生理解
授课时间：4月5日
教学内容：
Photosynthesis occurs only in the chlorophyll-containing cells of green plants, algae, and
certain protists 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 cellular respiration is highly exergonic and releases energy, photosynthesis requires energy and is highly endergonic.
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 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 (oxidized), 02 is released, and A TP and NADPH are formed. These reactions must take place in the presence of 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 A TP generated by the first set of reactions.
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，A TP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A TP。Both sets of reactions take place in chloroplasts. Most of the enzymes and pigments for the lightdependent reactions are embedded in the thylakoid membrane of chloroplasts. The dark reactions take place in the stroma.
两步反应都发生在叶绿体中。光反应需要的大部分酶和色素包埋在叶绿体的类囊体膜
上。暗反应发生在基质中。
How Light Energy Reaches Photosynthetic Cells（光合细胞如何吸收光能的）
The energy in light photons in the visible part of the spectrum can be captured by biological molecules to do constructive work. The pigment chlorophyll in plant cells absorbs photons
within a particular absorption spectrums statement of the amount of light absorbed by chlorophyll at different wavelengths. When light is absorbed it alters the arrangement of electrons in the absorbing molecule. The added energy of the photon boosts the energy
condition of the molecule from a stable state to a less-stable excited state. During the
light-dependent reactions of photosynthesis, as the absorbing molecule returns to the ground state, the "excess" excitation energy is transmitted to other molecules and stored as chemical
energy.
生物分子能捕获可见光谱中的光能。植物细胞中叶绿素在不同光波下吸收部分吸收光
谱。在吸收分子中，光的作用使分子中的电子发生重排。光子的能量激活了分子的能量状态，使其从稳定态进入不稳定的激活态。
All photosynthetic organisms contain various classes of chlorophylls and one or more
carotenoid (accessory) pigments that also contribute to photosynthesis. Groups of pigment molecules called antenna complexes are present on thylakoids. Light striking any one of the pigment molecules is funneled to a special chlorophyll a molecule, termed a reaction-center chlorophyll, which directly participates in photosynthesis. Most photosynthetic organisms possess two types of reaction-center chlorophylls, P680 and P700, each associated with an electron acceptor molecule and an electron donor. These aggregations are known respectively
as photosystem Ⅰ(P700) and photosystem Ⅱ(P680).
所有的光合作用生物含有不同等级的叶绿素和一个或多个类胡萝卜素（光合作用的辅助
色素）。称作天线复合体的色素分子群存在于类囊体中。激活色素分子的光能进入叶绿素
反应中心，其直接参与光合作用。大部分光反应细胞器拥有两套反应中心，P680和P700，每个光系统都含有一个电子受体和电子供体。这些集合体就是大家熟识的光合系统Ⅰ和光
合系统Ⅱ。
The Light-Dependent Reaction: Converting Solar Energy into Chemical-Bond Energy
光反应：光能转化成化学键能
The photosystems of the light-dependent reactions are responsible for the packaging of light energy in the chemical compounds A TP and NADPH. This packaging takes place through a
series of oxidation reduction reactions set in motion when light strikes the P680 reaction center
in photosystem Ⅱ. In this initial event water molecules are cleaved, oxygen is released, and electrons are donated. These electrons are accepted first by plastoquinone and then by a series
of carriers as they descend an electron transport chain. For each four electrons that pass down
the chain, two A TPs are formed. The last acceptor in the chain is the P700 reaction center of photosystem Ⅰ. At this point incoming photons boost the energy of the electrons, and they are accepted by ferredoxin. Ferredoxin is then reoxidized, and the coenzyme NADP+ is reduced to
the NADPH. The A TP generated previously and the NADPH then take part in the light independent reactions.
光反应的光系统将光能转化成化学复合物A TP和NADPH。当光激活光系统Ⅱ的光反应中
心时，通过一系列的氧化还原反应实现能量的传递。反应开始时，水被分解，氧被释放并
提供电子。电子首先传递给质体醌，然后通过一系列载体形成的电子传递链。每传递4个
电子，形成2个A TP。最后一个受体存在于光反应系统Ⅰ的反应中心里。此处光子激活电子，电子传递给铁氧还蛋白。铁氧还蛋白再氧化，并且辅酶NADP+还原成NADPH。早期产生的A TP和NADPH进入暗反应。
The production of A TP from the transport of electrons excited by light energy down an
electron transport chain is termed photophosphorylation. The one-way flow of electrons
through photosystems II and I is called noncyclic photophosphorylation; plants also derive additional A TP through cyclic photophosphorylation, in which some electrons are shunted
back through the electron transport chain between photosystems Ⅱand Ⅰ.
由电子传递链偶连产生A TP的过程称为光合磷酸化。通过光合系统Ⅱ流经光合系统Ⅰ的
电子路径称非循环式光合磷酸化；植物通过循环式光合磷酸化获得额外的A TP，一些电子
在光合系统Ⅰ和Ⅱ之间的电子传递链中回流。
The Light-Independent Reactions: Building Carbohydrates
暗反应：碳水化合物的形成
In the light-independent reactions of photosynthesis, which are driven by A TP and NADPH,
C02 is converted to carbohydrate. The reactions are also known as the Calvin-Benson cycle.
Atmospheric CO2, is fixed as it reacts with ribulose biphosphate (RuBP), a reaction that is
catalyzed by the enzyme ribulose biphosphate carboxylase. The reduction Of C02 to
carbohydrate (fructose diphosphate) is completed via several more steps of the cycle. Finally,
RUBP is regenerated so that the cycle may continue.
由A TP和NADPH驱动的暗反应中，二氧化碳转化成碳水化合物。即卡尔文循环。二磷酸
核酮糖固定二氧化碳，由二磷酸核酮糖羧化酶催化。
Oxygen: An Inhibitor of photosynthesis（氧：光合作用的抑制因子）
High levels of oxygen in plant cells can disrupt photosynthesis and can also cause
photorespiration-an inefficient fun of the dark reactions in which 02 is fixed rather than C02 and
no carbohydrate is produced.
Reprieve from Photorespiration: The C4 Pathway
Most plants are C3 plants; they experience decreased carbohydrate production under hot, dry
conditions as a result of the effects of photorespiration. Among C4 plants, however, special
leaf anatomy and a unique biochemical pathway enable the plant to thrive in and conditions.
Thus C4 plants lessen photorespiration by carrying out photosynthesis only in cells that are
insulated from high levels of CO2. They also possess a novel mechanism for carbon fixation.
大部分植物是碳3植物，在高温干旱条件下，由于光呼吸作用而使碳水化合物的合成降低。而在大多数的碳4植物中，由于叶脉的特殊构造和独特的化学路径使植物依然很茂盛。这是碳固定的一个新机制。课后作业：第一篇阅读材料
答案：1B,2A,3A,4D,5C,6c
Glossary
light-dependent reactions 光反应-
The first stage in photosynthesis, driven by
light energy. Electrons that trap the sun's
energy pass the energy to high-energy carriers
such as A TP or NADPH, where it is stored in
chemical bonds.
light-independent reactions 暗反应
The second stage of photosynthesis, also
called the Calvin-Benson cycle, which does
not require light. During the six steps of the
cycle, carbon is fixed and carbohydrates are
formed.
chloroplast 叶绿体
A plastid in which photosynthesis is carried
out. Chloroplasts occur in all photosynthetic
organisms except photosynthetic bacteria and
blue-green algae.
absorption spectrum 吸收光谱，吸收谱
The spectrum obtained when radiation
(light, ultraviolet radiation, etc.) from a source giving a continuous spectrum is passed through a substance.
Calvin-Benson cycle 卡尔文·本森循环Cyclic reactions that are the "synthesis" part of the light-independent reactions of photosynthesis. In land plants, RUBP, or some other compound to which carbon has been affixed, under goes rearrangements that lead to formation of a sugar phosphate and to regeneration of the RUBP. The cycle runs
on A TP and NADPH from light-dependent reactions.
carotenoid 类胡萝卜素
Light-sensitive, accessory pigments that transfer absorbed energy to chlorophylls. They absorb violet and blue wave-lengths but transmit red, orange, and yellow. chlorophyll 叶绿素
The green substance of plants by which photosynthesis is accomplished; it is
usually localized in intracellular organelles called chloroplasts.
cyclic photophosphorylation
环形光合磷酸化（作用）
Cyclic photophosphorylation is coupled to cyclicelectron flow, in which A TP is the only product.
C3 plant 三碳植物
A plant in which the light-independent reactions of photosynthesis start with a threecarbon compound. Most plants are C3 plants.
C4 plant 四碳植物
A plant such as corn in which the light independent reactions of photosynthesis star with a four-carbon compound.
noncyclic photophosphorylation
非环形光合磷酸化作用
Noncyclic photophosphorylation is coupled to noncyclic electron flow, the electrons being used to reduce NADP+ as well as to make
A TP.
photon 光子
A particle that has zero mass or charge and
unit spin, the quantum of the electromagnetic
field and carrier of the electromagnetic force.
photophosphorylation 光合磷酸化作用
The synthesis of A TP from phosphate and
ADP during photosynthesis, using light
energy.
photorespiration 光呼吸
A light-dependent type of respiration that
occurs in most photosynthetic plants and
differs from normal (or dark) respiration.
photosynthesis 光合作用
The synthesis of organic compounds by
reduction of carbon dioxide using light energy
absorbed by chorophyll.
photosystem 光合系统
One of the clusters of light-trapping
pigments embedded in photosynthetic
membranes. Photosystem I operates during
the cyclic pathway; photosystem Ⅱoperates
during both the cyclic and noncyclic
pathways. ribulose biphosphate (RUBP) 核
酮糖二磷酸
A compound with a backbone of five
carbon atoms that is required for carbon
fixation in the Calvin-Benson cycle of
photosynthesis.
thylakoid 类囊体
One of a number of flattened fluid-filled sacs
that form the photosynthetic lamellar system
of chloroplasts, photosynthetic bacteria, and
blue-green algae.
Lesson Three（2学时）
Cellular Reproduction: Mitosis and Meiosis
教学目的：使学生掌握细胞的有丝分裂和无丝分裂的作用机理，有丝分裂和无
丝分裂之间的区别和相同点。相关英语词汇以及主要用法。
教学重点：有丝分裂和无丝分裂中相关的概念和功能，及相关英语词汇的掌握
教学难点：专业英语词汇的记忆
讲授方法：以学生翻译为主，老师讲解相关专业知识辅助学生理解
授课时间：4月12日
教学内容：
The Nucleus and Chromosomes
The cell nucleus is the main repository of genetic information. Within the nucleus are the chromosomes tightly coiled strands of DNA and clusters of associated proteins. Long stretches
of the continuous DNA molecule wind around these clusters of proteins, or histones, forming beadlike complexes known as nucleosomes. More coiling and supercoiling produces a dense chromosome structure. Each long strand of DNA combines with histones and nonhistone
proteins to make up the substance chromatin.
细胞核是贮藏遗传信息的主要场所。DNA盘绕成螺旋线以及相关的成簇蛋白质。DNA
螺旋线缠绕成簇的组蛋白形成珠链状的核小体。这些螺旋和超螺旋形成致密的染色体组结
构。每个长链DNA与组蛋白和非组蛋白一起构成染色质物质。
A pictorial display of an organism's chromosomes in the coiled, condensed state is known
as a karyotype. Karyotype reveal that in most cells all but sex chromosomes are present as
two copies, referred to as homologous pairs. Non-sex chromosomes are called autosomes. Organisms whose cells contain two sets of parental chromosomes are called diploid; those with
cells containing a single set of parental chromosomes are called haploid.
染色体致密的超螺旋状态我们称染色体组。除了性染色体外，大多数细胞的染色体组成对出现，称同源染色体对。非性染色体称常染色体。生物细胞含有两套父母本染色体的称二倍体；含有单套染色体的称单倍体。
The Cell Cycle
The cell cycle is a regular sequence in which the cell grows, prepares for division, and
divides to form two daughter cells, each of which then repeats the cycle. Such cycling in effect makes single-celled organisms immortal. Many cells in multicellular organisms, including
animal muscle and nerve cells, either slow the cycle or break out of it altogether.
在细胞生长过程中，细胞循环遵循特定程序，分裂准备，分裂成2个子细胞，子细胞
再循环。此循环使得单细胞永生。多细胞生物中的许多细胞，包括动物肌肉和神经细胞，
要么降低循环速度，要么同时分裂。
The normal cell cycle consists of four phases. The first three include G1, the period of
normal metabolism; S phase, during which normal synthesis of biological molecules continues,
DNA is replicated, and histones are synthesized; and G2, a brief period of metabolism and additional growth. Together the G1, S, and G2 phases are called interphase. The fourth phase
of the cell cycle is M phase, the period of mitosis, during which the replicated chromosomes condense and move and the cell divides. It is believed that properties of the cell cytoplasm
control the cell cycle, along with external stimulators and inhibitors such as chalones.
正常细胞循环由4个时期组成。头三期包括G1,正常新陈代谢；S期,正常新陈代谢同时，DNA 复制，组蛋白合成；G2 期，短期的新陈代谢和少许生长。G1, S, 和G2称分裂间期。最后
是M期，有丝分裂期，复制的染色体组浓缩，移动并细胞分裂。据称是染色质控制了细胞
循环，伴随外部激活因子和抑制因子如抑素。
Mitosis: Partitioning the Hereditary Material
Biologists divide the mitotic cycle into four phases. At the beginning of prophase the chromosomes each consist of two highly condensed chromatids attached to each other at a centromere. As prophase ends and metaphase begins, the condensed chromosomes become associated with the spindle. Eventually the chromosomes become arranged in a plane (called
the metaphase plate) at a right angle to the spindle fibers. Next, during anaphase, the two
sister chromatids of each chromosome split, and one from each pair is drawn toward each pole
of the cell. During telophase nuclear envelopes begin to form around each set of
chromosomes, and division of the cytoplasm takes place.
生物学家将有丝分裂划分为4个阶段。分裂前期，高度浓缩的两个染色单体通过着丝
粒连接在一起。在分裂前期后期和分裂中期前期，浓缩的染色体与纺锤体相连，最后以正确的角度排列在赤道板上。在分裂后期，两个姊妹单体分离，分别拽向细胞两极。在分裂末期，在每套染色体周围形成核膜，细胞质发生分裂。
As mitosis proceeds, the spindle microtubules play a crucial role in ensuring that both
paired and separated chromatids move in the right directions at the proper times. Each half of the spindle forms as microtubules extend from each pole of a dividing cell to the region of the metaphase plate. During prophase, other microtubules, the centromeric fibers, extend
outward from the spindle poles to structures on the chromosomes called kinetochores.
During anaphase the fibers begin to shorten, and the chromatids begin to move apart.
在有丝分裂过程中，是纺锤体微管确保了染色单体在适当时间以正确方向进行分离。
纺锤体微管由两极向赤道板延伸。在分裂前期，其它微管，着丝粒纤维延伸到染色体的动粒。在分裂后期，纤维开始变短，染色单体分离。
The spindle forms differently in plant and animal cells. In animals it is associated with centriole, while in plant and fungal cells spindle formation is associated with reions called microtubule organizing centers.
植物和动物细胞形成的纺锤体不同。动物细胞与中心粒相连，而在植物和真菌细胞中，纺锤体与微管组织中心的离子相连。
Cytokinesis: Partitioning the Cytoplasm
胞质分裂：细胞质分离
The division of the cell cytoplasm at the end of mitosis is called cytokinesis. In animal
cells it takes place as a ring of actin filaments contracts around the cell equator, pinching the cell in two. In plant cells, which are bounded by a cell wall, cytokinesis involves the building of a new cell plate across the dividing cell at its equator. Cell wall material is then deposited in the region of the cell plate.
在动物细胞中，环形肌动蛋白丝延赤道板收缩而使细胞一分为二。在植物细胞中，在
赤道板形成新的细胞板。
Meiosis: The Basis of Sexual Reproduction
Meiosis is a special form of cell division that takes place in the reproductive organs that produce sex cells. Like mitosis, it takes place after DNA replication has occurred and involves two sequential nuclear divisions (meiosis I and meiosis Ⅱ). These divisions result in four daughter cells, each with half the number of chromosomes of the parent cell. The phenomenon of crossing over during meiosis results in exchanges of genetic information between chromosomes. Hence, the homologous chromosomes distributed to different progeny cells are not identical.
减数分裂是性细胞分裂的特殊形式。如有丝分裂，它也是发生在DNA复制后并有连续
的两个核分裂。产生4个子细胞，分别含有亲本一半的染色体数。
As in mitosis two chromatids exist for each chromosome at the beginning of prophase 1. During this phase the homologous chromosomes undergo synapsis, or pairing, which is brought about by a bridging structure of proteins and RNA called the synaptonemal complex. The homologous pairs stay together when they align on the metaphase plate. Unlike the anaphase
of mitosis, however, during anaphase I the two chromatids of each chromosome stay joined at the centromere and move together to one of the two poles of the cell. It is this event that results in the halving of the chromosome number in the four daughter cells that result from meiosis.
正如在有丝分裂中一样，两个同源染色单体通过蛋白质和RNA桥配对形成联会复合体。
与有丝分裂不同的是，每组染色体的两个染色单体连接在着丝点上并一起移向细胞两极的
一级。由此而导致4个子细胞染色体数减半。
During telophase I nuclear envelopes enclose the chromosomes in nuclei, and in most species cytokinesis (the first nuclear division) follows. The second nuclear division begins with metaphase Ⅱ, in which the chromosomes in each daughter cell again align on a metaphase plate. The centromeres finally divide, and each sister chromatid moves to one of the poles of the spindle. The next phase is telophase , followed again by cytokinesis. The result of the entire process is four haploid cells in which parental chromosomes are randomly distributed.
第二次核分裂开始于分裂中期，子细胞中染色体重新排列在赤道板上。着丝粒最终分离，
每个姊妹染色单体分向两极。接着胞质分裂。产生4个单倍体，父母染色体随机分配。Asexual V ersus Sexual Reproduction
Mitosis and meiosis, respectively, make simple cell division and sexual reproduction
possible. Each means of passing on hereditary information has advantages. In asexual reproduction the parent organism gives rise to offspring that are genetic clones of the parent.
The advantages of this type of reproduction are that it preserves the parent's successful genetic complement, requires little or no specialization of reproductive organs, and is more rapid than sexual reproduction. A major disadvantage of the asexual mode is that a single catastrophic
event or disease may destroy an entire population of genetically identical organisms. A prime
benefit of sexual reproduction is that it provides genetic variability and a ready mechanism for
the elimination of deleterious mutations. It also allows "new" gene forms to arise and spread through populations.
有丝分裂和减数分裂在传递遗传信息过程中各有优势。体细胞的繁殖就是父母本的克隆，其优势是保留了父母本的成功遗传信息，不需要特殊器官，比性复制快的多。但一个简单灾难性事件或疾病都可能摧毁一个细胞群体。性复制的优势是它提供了遗传可变性和现存排除有害突变的机制。也可以产生新的基因并在种群中蔓延。
课后作业：第一篇阅读材料
答案：1C,2B,3D,4B,5A,6D
Glossary
mitosis 有丝分裂
Process that results in equal and
identical distribution of replicated
chromosomes into two newly formed nuclei.
meiosis 减数分裂
The process by which a nucleus divides
into four daughter nuclei, each containing
half the number of chromosomes of the
parent nucleus.
histone 组蛋白
One of a group of simple proteins that
have a high content of the basic amino
acids arginine or lysine and are found
associated with nucleic acids in the
chromatin of eukaryotic cells.
nucleosome 核小体
The basic unit of chromatin structure in eukaryotic cells. A nucleosome consists of eight histone molecules of four different types, together with about 140 base pairs of DNA coiled around it.
chromatin 染色质
The material of which the chromosomes are composed. DNA and protein are the main constituents of chromatin, most of the protein being histone.
karyotype 核型，染色体组型,
The appearance of the chromosome complement of an organism or cell. homologous pair 同源染色体对Chromosomes that pair during meiosis. Each homologue is a duplicate
of one of the chromosomes contributed at syngamy by the mother or father. Homologous chromosomes contain the same linear sequence of genes and as a consequence each gene is present in duplicate.
diploid二倍体
Any nucleus, cell, or organism that possesses twice the haploid number of chromosomes.
haploid 单倍体
Any nucleus, cell, or organism that possesses a single set of unpaired chromosomes,
interphase (cycle) 分裂间期（周期）
In a cell preparing to duplicate, the interphase stage can divided into a period of initial growth (G1), a period of DNA synthesis (S), and a second growth period (G2).
chalone 抑素
Substances found in mammalian tissue homogenates that, when applied to intact tissue cells, inhibit mitosis, particularly in the presence of adrenaline and corticosteroids.
prophase （分裂）前期
First stage of mitosis, during which
individual chromosomes become visible.
chromatid 染色单体
A replicated chromosome physically
attached to an identical chromatid at the
centromere.
centromere 着丝粒
The small area of a chromosome that
does not stain with basic dyes during
mitosis and meiosis; at interphase it is
single while the rest of the chromosome is
made up of two chromatids.
metaphase （分裂）中期
Second stage in mitosis, during which the
chromosomes align at the equatorial plane.
spindle 纺锤体
An array of microtubutes extending
from pole to pole and used in the movement
of chromosomes.
metaphase plate 赤道板，中期板
The grouping of the chromosomes in a
plane at the equator of the spindle during
the metaphase stage of mitosis.
anaphase 分裂后期
The third stage of mitosis, during which
the centromeres split and the chromosomes
move to the poles.
telophase （分裂）末期
Last stage in mitosis during which
daughter nuclei are formed.
cytokinesis 胞质分裂Division of the cytoplasm of one cell into two
new cells.
cell plate 细胞板A plant cell structure that begins to form
in the center of the cell and proceeds to the
cell membrane, resulting in cytokinesis.
Lesson Four（2学时）
Foundations of Genetics
教学目的：使学生了解遗传学的发展历程，掌握孟德尔遗传学的建立及经典实验。相关英语词汇以及主要用法。
教学重点：孟德尔遗传学的两个定律，及相关英语词汇的掌握
教学难点：专业英语词汇的记忆
讲授方法：以学生翻译为主，老师讲解相关专业知识辅助学生理解
授课时间：4月19日
教学内容：
Early Theories of inheritanee
Early ideas of inheritance included Hippocrates' theory of pangenesis and August Weismands germ plasm theory. Based on experiments with mice, Weismann proposed that hereditary information in gametes transmitted traits to progeny. Both of these early views incorporated
the blending theory: they held that heritable traits of the two parents blend, so that the distinct characteristics of each are lost in offspring.
遗传学的早期理论包括泛生说和种质理论。基于小鼠实验，维丝曼提出遗传信息储存在配子中并将遗传信息传递给后代。这两个早期观点合起来形成融合理论：子代拥有父母本混合的遗传特征，而不完全象亲代。
Gregor Mendel and the Birth of Genetics
Gregor Mendel, an Augustinian monk in the monastery at Brunn, Austria, is known as the "father of genetics." Having been exposed to theories of the particulate nature of matter while a university student and having a background in mathematics, Mendel carried out a series of carefully planned experiments that demonstrated the particulate nature of heredity. His revolutionary ideas were neither understood nor accepted until many years after Mendel died.
孟德尔，众所周知的遗传学之父，是一名修道士。当他还是大学生时就提出了物质的粒子属性。孟德尔进行了一系列周密安排的实验来证实遗传的颗粒性。直到他去世后，他的理论才被理解和接受。
Mendel's Classic Experiments
Mendel studied genetics through plant-breeding experiments with the garden pea, a plant species that is self-fertilizing and breeds true (each offspring is identical to the parent in the trait of interest). To test the blending theory, he focused his research on seven distinct characters. Each of these characters, such as seed color and plant height, present only two, clear-cut possibilities. He also recorded the type and number of all progeny produced from each pair of parent pea plants, and followed the results of each cross for two generations.
孟德尔通过豌豆实验研究遗传学，豌豆是自花授粉植物和纯品系。为验证融合理论，他的研究主要集中在7个特征上。例如，种子颜色，植株高度，这些特征只有两个明确的可能性。他记录了产生的每一个子代类型和数量，在杂交产生子2代。
For each of the characters he studied, Mendel found that one trait was dominant while the
other was recessive. In the second filial (F2) generation, the ratio of dominant to recessive was 3:1. Mendel deduced that this result was possible only if each individual possesses only two hereditary units, one from each parent. The units Mendel hypothesized are today known as alleles, alternative forms of genes. Genes are the basic units of heredity. An organism that inherits identical alleles for a trait from each parent is said to be homozygous for that trait; if different alleles for a trait are inherited, the organism is heterozygous for that trait. When an organism is heterozygous for a trait, the resulting phenotype for that trait expresses only the dominant allele.Thus, the organism’s phenotype—its physical appearance and properties-differs from its genotype, which may include both a dominant and a recessive allele. A pictorial representation of all possible combinations of a genetic cross is known as a Punnett square.
对于每个特征而言，要么显形，要么隐性。在子2代中显形与隐性比为3∶1。只有在每个个体仅拥有两个研究遗传单元，并每个单元来自一个亲代时，实验结果才成立。此遗传单元就是今天共识的等位基因。两个一样的等位基因决定一个特征，称纯合。相反，称杂合。当生物是杂合时，它的表型由显性基因决定。因此，生物的表型与基因型是不同的。旁纳特方格可以陈列所有可能的遗传组合。
The results of Mendel's experiments on dominant and recessive inheritance let to Mendel's
first law: the law of segregation.This law states that for a given trait an organism inherits one allele from each parent. Together these alleles form the allele pair. When gametes are formed during meiosis, the two alleles become separated (halving of chromosome number).To gain evidence for his theory Mendel performed test crosses, mating plants of unknown genotype to plants that were homozygous recessive for the trait of interest. The ratio of dominant phenotypes (if any) in the progeny makes clear whether the unknown genotype is heterozygous, homozygous dominant, or homozygous recessive.
分离定律，生物只遗传父母本等位基因对的一个等位基因。减数分裂期形成配子时两
个等位基因分离。为验证此理论，他做了测交实验，即基因型未知的植物与纯合的隐性基因植物杂交。子代显性表型可以明确测得杂合基因或纯合基因的基因型。
Mendel's Ideas and the Law of independent Assortment
Mendel also performed dihybrid crosses, which enabled him to consider how two traits are inherited relative to one another. This work let to the law of independent assortment, which states that the alleles of genes governing different characters are inherited independently. An apparent exception to Mendel's laws is incomplete dominance, a phenomenon in which offspring of a cross exhibit a phenotype that is intermediate between those of the parents. However, incomplete dominance reflects the fact that both alleles for the trait in question exert an effect on the phenotype. The alleles themselves remain separate.
双因子杂合试验，两个特征是如何相互影响遗传的。试验结果产生独自分配定律，即等位基因独立遗传。特例是，不完全显性。子代的表型是父母本的中间类型。不完全显性说明了两个等位基因对表型都有影响。，等位基因会继续分离。
Mendel presented his ideas in 1866 in a scientific paper published by the Brunn Society for Natural History. Unfortunately, the meaning of his research was not understood by other scientists of the day. His work was rediscovered in 1900 by Carl Correns and Hugo de V ries. 1866年，孟德尔在自然史上发表了他的科学论文，陈诉了他的观点。不幸的是，他的研究不被当时科学家接受。在1900年，他的著作再被发现利用。
Chromosomes and Mendelian Genetics
Soon after Mendel's work was rediscovered, Walter Sutton and Theodor Boveri independently proposed that the hereditary units might be located on chromosomes. Experiments to prove
this hypothesis were carried out by Thomas Hunt Morgan and his students at Columbia University, in research on the sex chromosomes of fruit flies. Morgan's studies were also the first exploration of sex-linked traits. It also led to the discovery in 1916 by Calvin Bridges of the phenomenon of nondisjunction, in which a chromosome pair fails to segregate during meiosis.
孟德尔著作被再发现不久，Walter Sutton 和Theodor Boveri提出，遗传单位可能定位在
染色体组上。伴性遗传又导致了不分离现象的发现，即在减数分裂中，染色体对不分离。课后作业：第一篇阅读材料
答案：1C,2C,3A,4A,5B,6B
Glossary
pangenesis 泛生论，泛生说
The theory of heredity postulating that
germs, humours, or essences migrate from
individual body cells to the sex organs and
contribute to the gametes.
germ plasm theory 种质学说
A substance thought to be transmitted in
the gametes (germ cells) in an unchanged form from generation to generation. The germ plasm was believed to be unaffected by the environment and to give rise to the body cells.
dominant 显性
The member of a pair of alleles that shows its effect in the phenotype whatever other allele is present.
recessive 隐形的
The member of a pair of alleles that does not show its effect in the presence of any other allelic partner.
allele 等位基因
Alternative forms of a gene for a particular characteristic (e.g., attached earlobe genes and free earlobe genes are alternative alleles for ear shape).
gene 基因
A unit of heredity located on a chromosome and composed a sequence of DNA nucleotides.
homozygous 纯合的
A diploid organism that has two identical alleles for particular characteristic. heterozygous 杂合的
A diploid organism that has two different alletic forms of a particular gene. Genotype 基因型
The catalog of genes of an organism, whether or not these genes are expressed. phenotype 表型
The physical, chemical, and psychological expression of genes possessed by an organism.
Punnett square 旁纳特方格
A method used to determine the probabilities of combination in a zygote. law of segregation 分裂定律
When gametes are formed by a diploid organism, the alleles that control a trait separate from one another into different
gametes, retaining their individuality.
test cross 测交
A cross between a heterozygote of
unknown genotype and an individual
homozygous for the recessive genes in
question
.dihybrid cross 双因子杂种，双因子杂合子
A cross between individuals that differ
with respect to two specified gene pairs. law
of independent assortment 独立分配定律，
自由组合定律
Members of one gene pair will separate
from each other independently of the
members of other gene pairs.
incomplete dominance 不完全显性
The condition in which two allelic genes
have a different effect when they are together
as a heterozygote in a diploid cell than either
of them have in the homozygous state
nondisjunction 不分离
The failure of separation of paired
chromosomes at metaphase, resulting in one
daughter receiving both and the other
daughter cell none of the chromosomes in
question. Nondisjunction can occur during
a meiotic or mitotic division.
Lesson Five（2学时）
Discovering the Chemical Nature of the Gene
教学目的：使学生了解遗传学化学本质的发现过程，及相关假说，使学生掌握
相关专业词汇以及主要用法。
教学重点：DNA分子组成及相关英语词汇的掌握。
教学难点：专业英语词汇的记忆
讲授方法：以学生翻译为主，老师讲解相关专业知识辅助学生理解
授课时间：4月26日
教学内容：
Genes Code for Particular Proteins
The first scientist to investigate the question of how genes affect phenotype was Sir Archibald Garrod, whose studies of alkaptonuria implied a relationship between genes and enzymes. Thirty years later Beadle and Ephrussi showed a relationship between particular genes and biosynthetic reactions responsible for eye color in fruit flies. Next, in a series of classic experiments on the effects of mutations in the bread mold Neurospora crassa, Beadle and Tatum explored the one-gene-one-enzyme hypothesis-the idea that each gene codes for a particular enzyme. Their work paved the way for other researchers to elucidate the precise ways in which enzymes affect complex metabolic pathways.In 1949, in research on the role of hemoglobin in
第一章汽车总论 1)Today’s average car contains more than 15,000 separate, individual parts that must work together. These parts can be grouped into four major categories: body, engine, chassis and electrical equipment 。P1 现在的车辆一般都由15000多个分散、独立且相互配合的零部件组成。这些零部件主要分为四类：车身、发动机、底盘和电气设备。 2)The engine acts as the power unit. The internal combustion engine is most common: this obtains its power by burning a liquid fuel inside the engine cylinder. There are two types of engine: gasoline (also called a spark-ignition engine) and diesel (also called a compression-ignition engine). Both engines are called heat engines; the burning fuel generates heat which causes the gas inside the cylinder to increase its pressure and supply power to rotate a shaft connected to the power train. P3 发动机作为动力设备，常见的类型是内燃机，其原理是通过发动机缸内的液体燃料燃烧而产生能量。发动机可分为两类：汽油机（点燃式）和柴油机（压燃式），都属于热力发动机。燃料燃烧产生热量使缸内气压上升，产生的能量驱动轴旋转，并传递给动力传动系。 第二章内燃机 1)Power train system: conveys the drive to the wheels 2)Steering system: controls the direction of movement 3)Suspension system: absorbs the road shocks 4)Braking system: slows down the vehicle P4 传动系把发动机输出的扭矩传递给驱动轮。传动系包括离合器（对应机械变速器）或液力变矩器（对应液力自动变速器）、变速器、驱动轴、主减速器、差速器和驱动桥。 5)Drum brakes have a drum attached to the wheel hub, and braking occurs by means of brake shoes expanding against the inside of the drum. With disc brakes, a disc attached to the wheel hub is clenched between two brake pads. P6 鼓式制动器的制动鼓和轮毂连接，制动蹄张开压紧制动鼓内侧从而产生制动。在盘式制动器上，连着轮毂的制动盘被紧紧夹在两个制动块之间。 1)Linking the piston by a connecting rod to a crankshaft causes the gas to rotate the shaft through half a turn.The power stroke"uses up"the gas,so means must be provided to expel the burnt gas and recharge the cylinder with a fresh petrol-air mixture:this control of gas movement is the duty of the valves;An inlet valve allows the mixture to enter at the right time and an exhaust valve lets out the burnt gas after the gas has done its job . P10 活塞通过连杆和曲轴连接，使得气体带动曲轴旋转半圈。作功冲程耗尽了所有的气体，这样就必须采取相应的措施排出废气并且向气缸内充入新的可燃混合气：气体的运动由气门来控制。进气门使可燃混合气在恰当的时刻进入气缸，排气门使燃烧后的废气排出气缸。 2)The spark-ignition engine is an internal-combustion engine with externally supplied in ignition,which converts the energy cntained in the fuel to kinetic energy.The cycle of operations is spread over four piston strokes. To complete the full cycle it takes two revolutions of the crankshaft. P11 火花点火式发动机是由外部提供点火的内燃机，从而将含在燃料内的能量转化成动能。发动机的一个工作循环分布在活塞的四个行程中，一个完整的工作循环曲轴需要转动两圈。 3)The oil pump in the lubricating system draws oil from the oil pan and sends it to all working parts in the engine. The oil drains off and runs down into the pan. Thus,there is constant circulation of oil between the pan and the working parts of the engine. P15
Lesson 1 力学的基本概念 1、词汇： statics [st?tiks] 静力学；dynamics动力学；constraint约束；magnetic [m?ɡ＇netik]有磁性的；external [eks＇t?:nl] 外面的, 外部的；meshing啮合；follower从动件；magnitude [＇m?ɡnitju:d] 大小；intensity强度，应力；non-coincident [k?u＇insid?nt]不重合；parallel [＇p?r?lel]平行；intuitive 直观的；substance物质；proportional [pr?＇p?:??n?l]比例的；resist抵抗，对抗；celestial [si＇lestj?l]天空的；product乘积；particle质点；elastic [i＇l?stik]弹性；deformed变形的；strain拉力；uniform全都相同的；velocity[vi＇l?siti]速度；scalar[＇skeil?]标量；vector[＇vekt?]矢量；displacement代替；momentum [m?u＇ment?m]动量； 2、词组 make up of由……组成；if not要不，不然；even through即使，纵然； Lesson 2 力和力的作用效果 1、词汇： machine 机器；mechanism机构；movable活动的；given 规定的，给定的，已知的；perform执行；application 施用；produce引起，导致；stress压力；applied施加的；individual单独的；muscular [＇m?skjul?]]力臂；gravity[ɡr?vti]重力；stretch伸展，拉紧，延伸；tensile[tensail]拉力；tension张力，拉力；squeeze挤；compressive 有压力的，压缩的；torsional扭转的；torque转矩；twist扭，转动；molecule [m likju:l]分子的；slide滑动; 滑行；slip滑，溜；one another 互相；shear剪切；independently独立地，自立地；beam梁；compress压；revolve (使)旋转；exert [iɡ＇z?:t]用力，尽力，运用，发挥，施加；principle原则, 原理，准则，规范；spin使…旋转；screw螺丝钉；thread螺纹； 2、词组 a number of 许多；deal with 涉及，处理；result from由什么引起；prevent from阻止，防止；tends to 朝某个方向；in combination结合；fly apart飞散； 3、译文： 任何机器或机构的研究表明每一种机构都是由许多可动的零件组成。这些零件从规定的运动转变到期望的运动。另一方面，这些机器完成工作。当由施力引起的运动时，机器就开始工作了。所以，力和机器的研究涉及在一个物体上的力和力的作用效果。 力是推力或者拉力。力的作用效果要么是改变物体的形状或者运动，要么阻止其他的力发生改变。每一种
外文翻译 英文原文 Belt Conveying Systems Development of driving system Among the methods of material conveying employed，belt conveyors play a very important part in the reliable carrying of material over long distances at competitive cost．Conveyor systems have become larger and more complex and drive systems have also been going through a process of evolution and will continue to do so．Nowadays，bigger belts require more power and have brought the need for larger individual drives as well as multiple drives such as 3 drives of 750 kW for one belt(this is the case for the conveyor drives in Chengzhuang Mine)．The ability to control drive acceleration torque is critical to belt conveyors’performance．An efficient drive system should be able to provide smooth，soft starts while maintaining belt tensions within the specified safe limits．For load sharing on multiple drives．torque and speed control are also important considerations in the drive system’s design. Due to the advances in conveyor drive control technology，at present many more reliable．Cost-effective and performance-driven conveyor drive systems covering a wide range of power are available for customers’ choices[1]. 1 Analysis on conveyor drive technologies 1．1 Direct drives Full-voltage starters．With a full-voltage starter design，the conveyor head shaft is direct-coupled to the motor through the gear drive．Direct full-voltage starters are adequate for relatively low-power, simple-profile conveyors．With direct fu11-voltage starters．no control is provided for various conveyor loads and．depending on the ratio between fu11-and no-1oad power requirements，empty starting times can be three or four times faster than full load．The maintenance-free starting system is simple，low-cost and very reliable．However, they cannot control starting torque and maximum stall torque；therefore．they are
2、应力和应变 在任何工程结构中独立的部件或构件将承受来自于部件的使用状况或工作的外部环境的外力作用。如果组件就处于平衡状态,由此而来的各种外力将会为零,但尽管如此,它们共同作用部件的载荷易于使部件变形同时在材料里面产生相应的内力。 有很多不同负载可以应用于构件的方式。负荷根据相应时间的不同可分为: (a)静态负荷是一种在相对较短的时间内逐步达到平衡的应用载荷。 (b)持续负载是一种在很长一段时间为一个常数的载荷, 例如结构的重量。这种类型的载荷以相同的方式作为一个静态负荷; 然而,对一些材料与温度和压力的条件下,短时间的载荷和长时间的载荷抵抗失效的能力可能是不同的。 (c)冲击载荷是一种快速载荷(一种能量载荷)。振动通常导致一个冲击载荷, 一般平衡是不能建立的直到通过自然的阻尼力的作用使振动停止的时候。 (d)重复载荷是一种被应用和去除千万次的载荷。 (e)疲劳载荷或交变载荷是一种大小和设计随时间不断变化的载荷。 上面已经提到，作用于物体的外力与在材料里面产生的相应内力平衡。因此,如果一个杆受到一个均匀的拉伸和压缩，也就是说, 一个力,均匀分布于一截面,那么产生的内力也均匀分布并且可以说杆是受到一个均匀的正常应力,应力被定义为 应力==负载 P /压力 A, 因此根据载荷的性质应力是可以压缩或拉伸的,并被度量为牛顿每平方米或它的倍数。 如果一个杆受到轴向载荷，即是应力，那么杆的长度会改变。如果杆的初始长度L和改变量△L已知，产生的应力定义如下: 应力==改变长△L /初始长 L 因此应力是一个测量材料变形和无量纲的物理量 ,即它没有单位;它只是两个相同单位的物理量的比值。 一般来说,在实践中,在荷载作用下材料的延伸是非常小的, 测量的应力以*10-6的形式是方便的, 即微应变, 使用的符号也相应成为ue。 从某种意义上说，拉伸应力与应变被认为是正的。压缩应力与应变被认为是负的。因此负应力使长度减小。 当负载移除时，如果材料回复到初始的，无负载时的尺寸时，我们就说它是具有弹性的。一特定形式的适用于大范围的工程材料至少工程材料受载荷的大部分的弹性, 产生正比于负载的变形。由于载荷正比于载荷所产生的压力并且变形正比于应变, 这也说明,当材料是弹性的时候, 应力与应变成正比。因此胡克定律陈述, 应力正比于应变。 这定律服从于大部分铁合金在特定的范围内, 甚至以其合理的准确性可以假定适用于其他工程材料比如混凝土，木材，非铁合金。 当一个材料是弹性的时候，当载荷消除之后，任何负载所产生的变形可以完全恢复,没有永久的变形。
Lathes Lathes are machine tools designed primarily to do turning, facing and boring, Very little turning is done on other types of machine tools, and none can do it with equal facility. Because lathes also can do drilling and reaming, their versatility permits several operations to be done with a single setup of the work piece. Consequently, more lathes of various types are used in manufacturing than any other machine tool. The essential components of a lathe are the bed, headstock assembly, tailstock assembly, and the leads crew and feed rod. The bed is the backbone of a lathe. It usually is made of well normalized or aged gray or nodular cast iron and provides s heavy, rigid frame on which all the other basic components are mounted. Two sets of parallel, longitudinal ways, inner and outer, are contained on the bed, usually on the upper side. Some makers use an inverted V-shape for all four ways, whereas others utilize one inverted V and one flat way in one or both sets, They are precision-machined to assure accuracy of alignment. On most modern lathes the way are surface-hardened to resist wear and abrasion, but precaution should be taken in operating a lathe to assure that the ways are not damaged. Any inaccuracy in them usually means that the accuracy of the entire lathe is destroyed. The headstock is mounted in a foxed position on the inner ways, usually at the left end of the bed. It provides a powered means of rotating the word at various speeds . Essentially, it consists of a hollow spindle, mounted in accurate bearings, and a set of transmission gears-similar to a truck transmission—through which the spindle can be rotated at a number of speeds. Most lathes provide from 8 to 18 speeds, usually in a geometric ratio, and on modern lathes all the speeds can be obtained merely by moving from two to four levers. An increasing trend is to provide a continuously variable speed range through electrical or mechanical drives. Because the accuracy of a lathe is greatly dependent on the spindle, it is of heavy construction and mounted in heavy bearings, usually preloaded tapered roller or ball types. The spindle has a hole extending through its length, through which long bar stock can be fed. The size of maximum size of bar stock that can be machined when the material must be fed through spindle. The tailsticd assembly consists, essentially, of three parts. A lower casting fits on the inner ways of the bed and can slide longitudinally thereon, with a means for clamping the entire assembly in any desired location, An upper casting fits on the lower one and can be moved transversely upon it, on some type of keyed ways, to permit aligning the assembly is the tailstock quill. This is a hollow steel cylinder, usually about 51 to 76mm(2to 3 inches) in diameter, that can be moved several inches longitudinally in and out of the upper casting by means of a hand wheel and screw. The size of a lathe is designated by two dimensions. The first is known as the swing. This is the maximum diameter of work that can be rotated on a lathe. It is approximately twice the distance between the line connecting the lathe centers and the nearest point on the ways, The second size dimension is the maximum distance between centers. The swing thus indicates the maximum work piece diameter that can be turned in the lathe, while the distance between centers indicates the maximum length of work piece that can be mounted between centers. Engine lathes are the type most frequently used in manufacturing. They are heavy-duty machine tools with all the components described previously and have power drive for all tool movements except on the compound rest. They commonly range in size from 305 to 610 mm(12 to 24 inches)swing and from 610 to 1219 mm(24 to 48 inches) center distances, but swings up to 1270 mm(50 inches) and center distances up
About car engine Of all automobile components,an automobile engie is the most complicated assembly with dominant effects on the function of an autombile.So, the engine is generally called the"heat"of an automobile. 在汽车的所有部件中，汽车发动机是最复杂的组件，其对整车性能有着决定性的作用。因而发动机往往被称作发动机的“心脏”。 There are actually various types of engines such as electric motors,stream engines,andinternal combustion engines.The internal combustion engines seem to have almost complete dominance of the automotive field.The internal combustion engine,as its name indicates,burns fuel within the cylinders and converts the expanding force of the combustion into rotary force used to propel the vehicle. 事实上，按动力来源分发动机有很多种，如电动机、蒸汽机、外燃机等。然而内燃机似乎在发动机领域有着绝对的统治地位。就像其字面意思一样，内燃机的染料在气缸内燃烧，通过将燃烧产生气体的膨胀力转换成转动力来驱动发动机前进。 Engine is the power source of the automobile.Power is produced by the linear motion of a piston in a cylinder.However,this linear motion must be changed into rotary motion to turn the wheels of cars or trucks.The puston attached to the top of a connecting rod by a pin,called a piston pin or wrist pin.The bottom of the connecting rod is attached to the crankshaft.The connecting rod transmits the up-and-down motion of the piston to the crankshaft,which changes it into rotary motion.The connecting rod is mounted on the crankshaft with large bearings called rod bearing.Similar bearings, called main bearings,are used to mount the crankshaft in the block. 发动机是整部车的动力来源。能量来自于活塞在气缸内的（往复）直线运动。然而这种（往复）直线运动必须要转换成旋转运动才能驱动车轮。活塞与连杆通过一个销来连接，这个销称为活塞销。连杆的下部连接于曲拐。连杆把活塞的上下往复运动传递给曲拐，从而将往复直线运动转变成旋转运动。连杆和曲拐的连接使用大的轴承，称之为连杆轴承，类似的轴承也用于将曲轴连接到机体，称之为主轴承。 They are generally two different types of cooling system:water-cooling system and air-cooling system.Water-cooling system is more common.The cooling medium, or coolant, in them is either water or some low-freezing liquid, called antifreeze.A water-cooling system consists of the engine water jacket, thermostat, water pump, radiator, radiator cap, fan, fan drive belt and neccessary hoses. 主要有两种类型的冷却系统：水冷和风冷。水冷系统更为普遍。系统所用冷却介质或是冷却液常委水或其他低凝固点液体，称为抗凝剂。一个完整的水冷系统包括机体水套，节温器，水泵，散热器，散热器罩，风扇，风扇驱动皮带和必需的水管。 A water-cooling system means that water is used as a cooling agent to circulate through the engine to absorb the heat and carry it to the radiator for disposal.The ebgine is cooled mainly through heat transfer and heat dissipation.The heat generated by the mixture burned in the engine must be transferred from the iron or aluminum cylinder to the waterin the water jacket.The outside of the water jacket dissipates some of the heat to the air surrounding it, but most of the heat is carried by the cooling water to the radiator for dissipation.When the coolant temperature in the system reaches 90°,the termostat valve open fully, its slanted edge shutting off
机械制造专业英语文章 篇一：机械专业英语文章中英文对照 Types of Materials 材料的类型 Materials may be grouped in several ways. Scientists often classify materials by their state: solid, liquid, or gas. They also separate them into organic (once living) and inorganic (never living) materials. 材料可以按多种方法分类。科学家常根据状态将材料分为：固体、液体或气体。他们也把材料分为有机材料(曾经有生命的)和无机材料(从未有生命的)。 For industrial purposes, materials are divided into engineering materials or nonengineering materials. Engineering materials are those used in manufacture and become parts of products. 就工业效用而言，材料被分为工程材料和非工程材料。那些用于加工制造并成为产品组成部分的就是工程材料。 Nonengineering materials are the chemicals, fuels, lubricants, and other materials used in the manufacturing process, which do not become part of the product. 非工程材料则是化学品、燃料、润滑剂以及其它用于加工制造过程但不成为产品组成部分的材料。 Engineering materials may be further subdivided into: ①Metal ②Ceramics ③Composite ④Polymers, etc. 工程材料还能进一步细分为：①金属材料②陶瓷材料③复合材料④聚合材料，等等。 Metals and Metal Alloys 金属和金属合金 Metals are elements that generally have good electrical and thermal conductivity. Many metals have high strength, high stiffness, and have good ductility. 金属就是通常具有良好导电性和导热性的元素。许多金属具有高强度、高硬度以及良好的延展性。 Some metals, such as iron, cobalt and nickel, are magnetic. At low temperatures, some metals and intermetallic compounds become superconductors. 某些金属能被磁化，例如铁、钴和镍。在极低的温度下，某些金属和金属化合物能转变成超导体。 What is the difference between an alloy and a pure metal? Pure metals are elements which come from a particular area of the periodic table. Examples of pure metals include copper in electrical wires and aluminum in cooking foil and beverage cans. 合金与纯金属的区别是什么？纯金属是在元素周期表中占据特定位置的元素。 例如电线中的铜和制造烹饪箔及饮料罐的铝。 Alloys contain more than one metallic element. Their properties can be changed by changing the elements present in the alloy. Examples of metal alloys include stainless steel which is an alloy of iron, nickel, and chromium; and gold jewelry which usually contains an alloy of gold
High-speed milling High-speed machining is an advanced manufacturing technology, different from the traditional processing methods. The spindle speed, cutting feed rate, cutting a small amount of units within the time of removal of material has increased three to six times. With high efficiency, high precision and high quality surface as the basic characteristics of the automobile industry, aerospace, mold manufacturing and instrumentation industry, such as access to a wide range of applications, has made significant economic benefits, is the contemporary importance of advanced manufacturing technology. For a long time, people die on the processing has been using a grinding or milling EDM (EDM) processing, grinding, polishing methods. Although the high hardness of the EDM machine parts, but the lower the productivity of its application is limited. With the development of high-speed processing technology, used to replace high-speed cutting, grinding and polishing process to die processing has become possible. To shorten the processing cycle, processing and reliable quality assurance, lower processing costs. 1 One of the advantages of high-speed machining High-speed machining as a die-efficient manufacturing, high-quality, low power consumption in an advanced manufacturing technology. In conventional machining in a series of problems has plagued by high-speed machining of the application have been resolved. 1.1 Increase productivity High-speed cutting of the spindle speed, feed rate compared withtraditional machining, in the nature of the leap, the metal removal rate increased 30 percent to 40 percent, cutting force reduced by 30 percent, the cutting tool life increased by 70% . Hardened parts can be processed, a fixture in many parts to be completed rough, semi-finishing and fine, and all other processes, the complex can reach parts of the surface quality requirements, thus increasing the processing productivity and competitiveness of products in the market. 1.2 Improve processing accuracy and surface quality High-speed machines generally have high rigidity and precision, and other characteristics, processing, cutting the depth of small, fast and feed, cutting force low, the workpiece to reduce heat distortion, and high precision machining, surface roughness small. Milling will be no high-speed processing and milling marks the surface so that the parts greatly enhance the quality of the surface. Processing Aluminum when up Ra0.40.6um, pieces of steel processing at up to Ra0.2 ~ 0.4um.
1.2 总线互连 总线是连接两个或多个设备的通信通路。总线的关键特征是，它是一条共享传输介质。多个设备连接到总线上，任一个设备发出的信号可以为其他所有连接到总线上的设备所接收。如果两个设备同时传送，它们的信号将会重叠，引起混淆。因此，一次只能有一个设备成功地（利用总线）发送数据。 典型的情况是，总线由多条通信通路或线路组成，每条线(路)能够传送代表二进制1和0的信号。一段时间里，一条线能传送一串二进制数字。总线的几条线放在一起能同时并行传送二进制数字。例如, 一个8位的数据能在8条总线线上传送。 计算机系统包含有多种不同的总线，它们在计算机系统层次结构的各个层次提供部件之间的通路。连接主要计算机部件(处理机, 存储器, I/O)的总线称为系统总线。系统总线通常由50~100条分立的(导)线组成。每条线被赋予一个特定的含义或功能。虽然有许多不同的总线设计，但任何总线上的线都可以分成三个功能组：数据线、地址线和控制线。此外可能还有为连接的模块提供电源的电源线。 数据线提供系统模块间传送数据的路径，这些线组合在一起称为数据总线。典型的数据总线包含8、16或32根线，线的数量称为数据总线的宽度。因为每条线每次传送1位，所以线的数目决定了每次能同时传送多少位。数据总线的宽度是决定系统总体性能的关键因素。 地址线用于指定数据总线上数据的来源和去向。例如，如果处理机希望从存储器中读一个字的数据，它将所需要字的地址放在地址线上。显然，地址总线的宽度决定了系统最大可能的存储器容量。 控制线用来控制对数据线和地址线的访问和使用。由于数据线和地址线被所有部件共享，因此必须用一种方法来控制它们的使用。控制信号在系统模块之间传送命令和定时信息。定时信息指定了数据和地址信息的有效性，命令信号指定了要执行的操作。 大多数计算机系统使用多总线，这些总线通常设计成层次结构。图1.3显示了一个典型的高性能体系结构。一条局部总线把处理机连接到高速缓存控制器，而高速缓存控制器又连接到支持主存储器的系统总线上。高速缓存控制器集成到连接高速总线的桥中。这一总线支持连接到：高速LAN、视频和图形工作站控制器，以及包括SCSI 和FireWire的局部外设总线的接口控制器。低速设备仍然由分开的扩充总线支持，用一个接口来缓冲该扩充总线和高速总线之间的通信流量。 PCI 外部设备互连是流行的高带宽的、独立于处理机的总线，它能够作为中间层或外围设备总线。当前的标准允许在66MHz频率下使用多达64根数据线，其原始传输速率为528MB/s, 或4.224Gbps。PCI被设计成支持各种各样基于微处理机的配置，包括单处理机和多处理机的系统。因此，它提供了一组通用的功能。PCI使用同步时序以及集中式仲裁方案。 在多处理机系统中，一个或多个PCI配置可通过桥接器连接到处理机的系统总线上。系统总线只支持处理机/高速缓存单元、主存储器以及PCI桥接器。使用桥接器使得PCI独立于处理机速度，又提供快速接收和传送数据的能力。 2.1 光存储介质：高密度存储器 2.1.1 光盘 光盘技术最终可能使磁盘和磁带存储淘汰。用这种技术，磁存储器所用的读/写头被两束激光代替。一束激光通过在光盘上刻制微小的凹点，对记录表面进行写；而另一束激光用来从光敏感的记录表面读取数据。由于光束容易被偏转到光盘上所需要的位置，所以不需要存取臂。 对用户而言，光盘正成为最有吸引力的选择。它们(光盘)对环境变化不太敏感，并且它们以每兆字节比磁盘低得多的存储器价格提供更多的直接存取存储器。光盘技术仍在出现，并且还需要稳定；然而，目前有三种主要类型的光盘。它们是CD-ROM、WORM盘和磁光盘。 CD-ROM 1980年引入的，非常成功的CD，或紧密盘是设计来提高音乐的录音重放质量的光盘。为了制作一张CD，把音乐的模拟声音转换成等价的数字声音，并且存储在一张4.72英寸的光盘上。在每张光盘上可以用数字格式（用20亿数字位）记录74分钟的音乐。因为它的巨大存储容量，计算机工业的企业家们立刻认