Suppose you wish to select an RNA molecule that catalyzes the hydrolysis of a particular ester. From what you know about catalysis, propose a SELEX strategy that might allow you to select the appropriate catalyst。

(c)假设你想选出一种可以催化某种特定酯水解的RNA分子。根据你对水解的所知，设计一个可以使你选到合适的催化剂的SELEX策略。

Louis Pasteur had shown in 1848 that tartaric acid has optical activity and that this depends on molecular asymmetry, and Jacobus H. van’t Hoff and Joseph-Achille Le Bel (1847-1930)had independently explained in 1874 how a molecule with a carbon atom bonded to four different groups has two mirror-image forms.

1848年巴斯德指出酒石酸具有光学活性，取决于它的分子不对称性。范托夫和贝勒于1874年分别独立地解释了与四个不同的基团结合的碳原子所组成的分子如何有两种互为镜像的形式。

Gel fillration of BSA gives a molecular weight estimate of 70，000. How many tryptophan residues are present in a molecule of serum albumin?

BSA的凝胶过滤给出分子量为70，000.BSA分子中有多少个Trp残基?

How does the DNA molecule fit into the cell?

DNA分子是如何装配在细胞中的?

Each nucleotide triplet on mRNA specifies which amino acid comes next on the protein being synthesized, and a tRNA molecule with that triplet’s complement on its protruding end brings the specified amino acid to the site of synthesis to be linked into the protein. Various minor types of RNA also exist; at least some act as catalysts (ribozymes), a function long ascribed only to proteins

MRNA上的每个核酸三联体具体说明氨基酸将要合成的蛋白质，而tRNA分子在突出端具有三联体的互补体，指定氨基酸到链接成蛋白质的定位。还存在各种较小的RNA种类，至少有些是作为催化剂(核醣)，长久以来认为专属蛋白质的功能。

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。

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。

Chelate: Any of a class of coordination or complex compounds consisting of a central atom of a metal (usually a transition element)attached to a large molecule (ligand).

螯合物:一类配位化合物或错合物。它是由一个大分子(配位体)与一个中心金属(通常是过渡元素)原子连结而成。

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醣的一个分子构成

Allosteric control Inhibition or activation of an enzyme by a small regulatory molecule that interacts with the enzyme at a site (allosteric site)other than the active site (at which catalytic activity occurs).

变构调控:在变构位点而非活性中心(发生催化活动的地方)上受小分子(调节分子)作用而被抑制或激活的现象。

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。

This function appears to be related to a distinctive property of chondroitin sulfate: the volume occupied by the molecule is much greater in solution than in the dehydrated solid. Why is the volume occupied by the molecule so much larger in solution?

此功能似乎与硫酸软骨素的独特性质有关:这个分子在溶液中所占的体积比在脱水固体状态下要大得多。为什么这种分子在溶液中所占体积如此之大?

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。

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

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

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。

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。

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。

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。

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。

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

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。

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。

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。

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。

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象。

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。

Ribose: Five-carbon sugar found in RNA. (In DNA the corresponding sugar is the closely related deoxyribose.)A ribose molecule combined with adenine, guanine, cytosine, or uracil forms a nucleoside; adding a phosphate group forms a nucleotide.

核糖:核糖核酸中的五碳糖。(去氧核糖核酸中相应的糖类和去氧核糖密切相关)核糖分子和腺嘌呤、鸟嘌呤、胞嘧啶或尿嘧啶形成核;再加上磷酸盐和磷酸酯便成为核。

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

Draw the structure of histidine in each ionization state. What is the net charge on the histidine molecule in each ionization state?

画出组氨酸的每种解离结构。每种解离状态下的净电荷是多少?

free molecule

n.自由分子

molecule deep

adj.分子厚度的

hair molecule

n.毛状分子

macro molecule

n.大分子

mumesic molecule

n.μ介子分子

molecule lattice

分子格子

protein molecule

n.蛋白质分子

network molecule

网络分子

rod-like molecule

n.棒状分子

extended molecule

扩展分子

globular molecule

n.球状分子

molecule structure

分子结构

tschermak molecule

n.契尔马克分子

monatomic molecule

单原子分子

parent molecule ion

n.母分子离子

interacting molecule

n.相互作用分子

dissymmetric molecule

不对称分子

ion molecule reaction

离子分子反应

molecule model program

分子模型程序

trifunctional molecule

n.三官能分子

doublet sigma molecule

对偶Σ粒子分子，对偶西格马分子

large aromatic molecule

大芳香族分子

straight chain molecule

直链分子

asymmetric top molecule

n.不对称陀螺分子

bound excitonic molecule

边界激子分子

complex organic molecule

n.络合有机分子

multifunctional molecule

n.多官能团分子

linear polymeric molecule

n.线型聚合分子

homonuclear diatomic molecule

n.同核双原子分子

tetrahedrally-symmetrical molecule

n.四面体对称分子