Just as the discovery of the electron in 1897 was seminal event for the 20th century, the seeds for the 21st century were spawned in 1953,when James blurted out to Francis how four nuclei acids could pair to form the self-copying code of a DNA molecule .

1897年电子的发现为20世纪(物理学的世纪)奠定了基础,1953年已经为21世纪(生物技术的世纪)播下了种子,当年詹姆斯·华生向弗朗西斯·克里克脱口说出了四个核酸如何能够配对而形成一个脱氧核糖核酸(DNA)分子的自行复制编码。

属类：社会文化-新闻报道-

How does the DNA molecule fit into the cell?

DNA分子是如何装配在细胞中的?

属类：化学及生命科学-化学-化学习题

Closest to the functional group of atoms in an organic molecule .

阿尔法位的,第一位的在有机分子中离功能原子基团最近的

属类：综合句库--

A molecule of ammonia is made up of one atom of nitrogen and three atoms of hydrogen.

氨分子包含一个氮原子和三个氢原子。

属类：综合句库--

Carbamic acid is formed in reaction(1)and this picks up another molecule of ammonia to give ammonium carbamate

氨基甲酸按反应(1)生成,它结合另一分子氨生成氨基甲酸铵。

属类：综合句库--

These can include a minor change in a molecule , fragmentation, or complete mineralization.

包括分子的微小变化,裂解或者完全矿化作用。

属类：工程技术-食品工程-

A white,crystalline nucleoside,C9H13N3O5,composed of one molecule each of cytosine and ribose.

胞苷一种白色的晶状核苷,C9H13N3O5,由每个胞核嘧啶和核糖的一个分子构成

属类：综合句库--

The symmetric structure of oxalic acid molecule and two carboxylic group on both ends ensure the stableness of C=C double bond.

草酸分子属于对称结构,两端的羧基使两个碳原子稳定化。

属类：化学及生命科学-化学-臭氧氧化

The molecular weight of an E. coli DNA molecule is about 3.1 X 109. The average molecular weight of a nucleotide pair is 660, and each nucleotide pair contributes 0.34 nm to the length of DNA.

大肠杆菌的DNA分子的分子量为3.1×109,核苷酸对的平均分子量为660,每个核苷酸对DNA长度上的贡献为0.34nm。

属类：化学及生命科学-化学-化学习题

A nucleotide consisting of one molecule each of a phosphoric acid,a sugar,and either a purine or a pyrimidine base.

单核苷酸磷酸、糖、嘌呤或嘧啶碱基中的一种,它组成的一个分子的苷酸

属类：综合句库--

A single ribosome,especially one that is combined with a molecule of messenger RNA.

单核糖体单核糖体,尤指与信使核糖核酸的一个分子相结合的单核糖体

属类：综合句库--

Monomer Molecule of any of a class of mostly organic compounds that can react with other molecules of the same or other compounds to form very large molecules (polymers).

单体:能与其它相同分子或者其它化合物分子反应而组成十分大的分子(聚合物)的任何一类分子(大多数是有机化合物)。

属类：化学及生命科学-化学-

Whenever two monomer molecules react, the product must contain a functional group capable of reacting with another molecule of monomer.

当两个单体分子发生反应时,其产物中必须具有可与另一单体反应的官能团。

属类：化学及生命科学-化学-

When a molecule contains two or more atoms of the same kind, a subscript indicates the number present

当某一分子包含两个或多个同种原子时,就用一个角标表示该原子的数目。

属类：综合句库--

Iodine: Nonmetallic chemical element, chemical symbol I, atomic number 53. The heaviest nonradioactive halogen, it is a nearly black crystalline solid (diatomic molecule I2)that sublimes (see sublimation)to a deep violet, irritating vapour. It is never found in nature uncombined.

碘:非金属化学元素,化学符号I,原子序数53。是最重的非放射性卤素,为几近黑色的晶体(双原子分子I2),升华后为深紫色刺激性的蒸气,在自然界从不以元素状态存在。

属类：化学及生命科学-化学-

Ionization potential (ionization energy): Amount of energy required to remove an electron from an isolated atom or molecule .

电离电势(亦称电离能):从孤立原子或分子中移去一个电子所需要的能量。

属类：化学及生命科学-化学-

Symmetry operations are geometrically defined ways of exchanging equivalent parts of a molecule

对称操作几何上定义为交换分子中等价部分的方式。

属类：综合句库--

A sulfide compound containing at least two sulfur atoms per molecule

多硫化物每个分子中至少含有两个硫原子的一种硫化物

属类：综合句库--

Molecular weight: Mass of a molecule of a substance, based on 12 as the atomic weight of carbon-12.

分子量:物质的分子质量,依据的事实是1莫耳的碳-12的质量是12克。

属类：化学及生命科学-化学-

Differ in the way in which the atoms within the molecule are oriented in space are called stereoisomer

分子中原子在空间定向的方式不同的化合物叫做立体异构体。

属类：综合句库--

Cofactor: An atom, organic molecule , or molecular group that is necessary for the catalytic activity of many enzymes.

辅助因子:许多的一种非蛋白质组分。如果将其从全中除去,则蛋白质部分(脱辅基蛋白)便失去催化活性。

属类：化学及生命科学-化学-

An important metabolic intermediate as well as a neurotransmitter molecule in the central nervous system, glutamic acid finds uses in medicine and biochemical research. Its sodium salt is the food flavour enhancer monosodium glutamate (MSG).

谷氨酸是重要的代谢中间产物,也是中枢神经系统的神经介质分子,谷氨酸用于医学和生化的研究。谷氨酸钠(即味精)广泛用作调味品。

属类：化学及生命科学-化学-

Framework models provide an excellent view of the skeletal shape of a molecule

骨架模型提供了分子骨架形状的极好图像。

属类：综合句库--

Functional: group In molecules, any of numerous combinations of atoms that undergo characteristic chemical reactions themselves and in many cases influence the reactivity of the rest of the molecule .

官能团构成分子的一部分,因为它本身具有特征性反应,致在许多情况下影响分子其余部分反应性的多种原子组合的总称。

属类：化学及生命科学-化学-

Orbital Mathematical expression, called a wave function, that describes properties characteristic of no more than two electrons near an atomic nucleus or molecule .

轨道:数学表述,称为波函数,它描述原子核附近的或分子中的原子核系统附近的电子不能多于两个这一特性。

属类：化学及生命科学-化学-

The chimaeric molecule , containing the vector DNA and inserted foreign DNA, is introduced into bacterial cells where it multiplies

含有载体的DNA以及插入的外源基因的杂合子,被引入细菌细胞,并且在其中增殖。

属类：综合句库--

Of or relating to the specific pairing of the purines and pyrimidines between strands of a DNA or an RNA molecule .

互补的指DNA或RNA分子链之间特定的嘌呤和嘧啶碱基对的互补

属类：综合句库--

Cycloalkanes have ring structures (but are not aromatic compounds)with two fewer hydrogen atoms per molecule than the corresponding alkane; many have more than one ring. Commercial sources include petroleum and natural gas. Uses, often as mixtures, include fuels, solvents, and raw materials.

环烷烃是每个分子含有比相同的烷烃少两个氢原子的环状结构(但不是芳香族化合物);许多含有一个以上的环。商业上的来源包括石油和天然气。通常以混合物的形式用作燃料、溶剂和原料。

属类：化学及生命科学-化学-

In other words such a molecule is pictured much as if it were a conducting helix

换句话说,这样一个分子的图像很像一条导电的螺旋线。

属类：综合句库--

Virtually any large foreign molecule can act as an antigen, including those of bacteria, viruses, parasites, foods, venoms, blood components, and cells and tissues of various species, including other humans. Sites on the antigen's surface fit and bind to receptor molecules on the lymphocytes' surface, stimulating the latter to multiply and initiate an immune response that neutralizes or destroys the antigen.

几乎所有的外来大分子皆可做为抗原,如细菌、病毒、原虫、蠕虫、食物、蛇毒、蛋白、血清、红血球,以及包括人类在内的各种生物细胞的各个组成即是。抗原上面存在一或数个可与淋巴球表面接受体结合的部位,称之为抗原决定部位,当抗原决定部位与淋巴球表面接受体结合后,可以活化淋巴球,使其开始分裂繁殖或引发一系列免疫反应如制造抗体和活化杀手细胞等以对抗抗原之侵入。

属类：化学及生命科学-化学-