chirality
chirality — 形容詞
- chiralitypositive
- more chiralitycomparative
- most chiralitysuperlative
1. describes an individual molecule or object whose mirror-image counterpart cannot
手性的
分子與鏡像無法經旋轉完全重合的幾何特性
describes an individual molecule or object whose mirror-image counterpart cannot be aligned with the original by any rotation — the geometric property of handedness, illustrated by a left hand and a right hand that are mirror images but cannot occupy the same glove.
A chiral molecule, like the compound limonene, has left-handed and right-handed forms that smell completely different.
像檸烯這類手性分子，其左旋與右旋形式的氣味截然不同。
chiral + molecule; attributive use before noun
Niran checked whether the crystal was chiral by comparing it with its mirror image under the microscope.
Niran 在顯微鏡下比對晶體與其鏡像，以確認該晶體是否具有手性。
predicative: is / was chiral
A person's left and right hands are chiral because one glove cannot fit both hands equally well.
人的左右手具有手性，因為一隻手套無法同時完美貼合兩隻手。
When Eitan synthesised the chiral compound limonene in the lab, both mirror versions appeared together in the final mixture.
Eitan 在實驗室合成手性化合物檸烯時，兩種鏡像版本同時出現在最終混合物中。
- non-superimposable
more literal and technical; describes the specific geometric relationship rather than a general class property
- enantiomorphic
rare; used mainly in crystallography to describe mirror-image crystal forms
- achiral
describes a molecule whose mirror image CAN be placed exactly on top of the original (e.g. methane, water)
文法句型
chiral + noun (molecule / compound / object / structure)
is / are chiral
用法筆記
Commonly used attributively before nouns like 'molecule', 'compound', 'substance', or 'catalyst'. The term comes from the Greek word for 'hand' — the hand is the classic example of a chiral object whose mirror image (the opposite hand) does not match the original.
常見錯誤
2. identifying a chemical substance or system as belonging to the class of compound
具手性的
屬於具有鏡像分子形式的化合物類別
identifying a chemical substance or system as belonging to the class of compounds that exist as two distinct mirror-image forms, used when discussing their classification, recognition, or separation rather than the geometric relationship itself.
Glucose and other sugars are naturally chiral, and each mirror version rotates plane-polarised light in a different direction.
葡萄糖等糖類天然即具手性，每種鏡像版本會將平面偏振光朝不同方向旋轉。
predicative use: be + chiral
The chiral nature of DNA determines how the molecule twists and fits inside the cell nucleus.
DNA 的具手性結構決定了它如何在細胞核內扭轉與組裝。
attributive: chiral + nature
Rohan studied the chiral environment inside the enzyme to understand why only the left-handed form of the drug was produced.
Rohan 研究了該酵素內部的具手性環境，以了解為何只有藥物的左旋形式被合成出來。
Pharmaceutical companies must test each chiral version of a new drug separately for safety and effectiveness.
藥廠必須分別測試新藥的每種具手性版本，以確保其安全性與有效性。
- optically active
a property-based synonym; chiral compounds rotate plane-polarised light, though not all chiral substances are optically active in all forms
文法句型
chiral + noun (nature / environment / interaction / separation / recognition)
be chiral in nature / form
用法筆記
This sense focuses on the classification of substances as belonging to the chiral class — it is the most general of the three senses. Unlike sense 1, which emphasises the structural relationship to a mirror image, this sense simply identifies substances or phenomena that have the property of chirality.
常見錯誤
3. describing a specific atom within a molecule — most often a carbon atom — that h
不對稱中心
分子中連接四個不同基團的不對稱原子
describing a specific atom within a molecule — most often a carbon atom — that has four different atoms or groups attached to it, making the whole molecule capable of existing as mirror-image forms.
In alanine, the central carbon atom is called a chiral center because it bonds to four different groups.
在胺基酸丙胺酸中，中央碳原子因為連接四個不同的取代基，因此稱為不對稱中心。
attributive: chiral + center (most common collocation)
Soraya found three chiral carbon atoms in the plant compound by examining its structure with X-ray analysis.
Soraya 利用 X 光繞射分析該植物化合物的結構，找到了三個不對稱的碳原子。
attributive: chiral + carbon
The chiral carbon in lactic acid determines whether the solution rotates polarised light left or right.
乳酸中的不對稱碳原子決定了溶液將偏振光向左旋或向右旋。
Removing the hydroxyl group from the chiral center of lactic acid destroys its ability to exist as two mirror-image forms.
從乳酸的不對稱中心移除羥基之後，該分子便失去以兩種鏡像形式存在的能力。
Bao mapped all the chiral centers in the protein to understand how the molecule folds inside the cell.
Bao 繪製了該蛋白質中所有不對稱中心的位置，以了解分子在細胞內部的折疊方式。
- asymmetric center
the preferred term in many textbooks; 'asymmetric' is broader but in this context refers specifically to a tetrahedral atom with four different substituents
- stereocenter
broader term that includes but is not limited to chiral centers; any atom where swapping two groups gives a different stereoisomer
文法句型
chiral + noun (center / carbon / atom / molecule)
用法筆記
This sense is narrower than senses 1 and 2: it refers specifically to an atom (the source of chirality) rather than the whole molecule. The most common collocations are 'chiral center' and 'chiral carbon.' A molecule may have one, several, or no chiral centers. Frequently used in stereochemistry and pharmaceutical research writing.