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1 Markets I: The Ecosystem and Exchange-Traded Markets市场在线 2 Markets II: Rates, FX and Credit市场在线 3 Markets III: Commodities, Energy and Crypto市场在线 4 Quantitative Methods方法在线 5 Derivatives and Volatility衍生品在线 6 Rates, Credit, XVA and Risk利率、信用与风险在线 7 Research Craft: Predictors, Backtests, Measurement, Portfolios研究在线 8 Strategies I: Equities and Futures策略在线 9 Strategies II: Volatility, Relative Value, Macro and the Bank Desks策略在线 10 Microstructure and Execution交易执行在线 11 Market Making and High-Frequency Trading做市在线 12 Machine Learning for Markets机器学习在线 13 Low-Latency Software技术在线 14 Networks, Hardware and Trading Infrastructure技术在线 15 Research, Data and Risk Platforms技术在线 16 The Desk and the Firm公司运营在线 17 The Industry: Firms, Roles and Careers职业发展在线 18 Interviews I: Maths, Probability and Speed职业发展在线 19 Interviews II: Markets, Trading Games and the Final Round职业发展在线 20 Interviews III: Code职业发展在线

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Biology · 术语表

什么是 Organelle？

又称： nucleus · mitochondrion · chloroplast · vacuole · cell wall · ribosome

Definition 2.8 High School Biology · 第 2 章 — Cells: The Common Unit of Life

An organelle is a structure inside a cell, enclosed by its own membrane, that performs a specific task. The principal ones are:

the nucleus, which contains the chromosomes — the DNA of Chapter 3 — and controls the cell’s activity;
the mitochondria, some $1\,\text{µ}\mathrm{m}$ long, where organic molecules are broken down with oxygen to release usable energy (cellular respiration, Chapter 4);
in plant cells, the chloroplasts, green with chlorophyll, where photosynthesis takes place, and a large water-filled vacuole that keeps the cell taut.

Outside the membrane, a plant cell is boxed in a rigid cell wall of cellulose; animal cells have none. The cytoplasm of every cell also contains millions of ribosomes, particles of about $25\,\mathrm{nm}$ that assemble proteins, visible only with the electron microscope.

Two eukaryotic cells, schematically. Both have a membrane, a cytoplasm with mitochondria (orange) and a nucleus; the plant cell adds a cellulose wall, chloroplasts (green) and a large central vacuole. Neither is drawn to scale: a real nucleus is about a tenth of the cell’s width, and mitochondria are a hundred times smaller than the cell.

示例

Example 2.7 (Cheek cells)

A cheek cell drawn $24\,\mathrm{mm}$ wide from a $\times 400$ image is $24/400 = 0.06\,\mathrm{mm} = 60\,\text{µ}\mathrm{m}$ across, and its nucleus, drawn $3\,\mathrm{mm}$ , is about $8\,\text{µ}\mathrm{m}$ . A red blood cell is $7\,\text{µ}\mathrm{m}$ ; the bacteria of the mouth, $1\,\text{µ}\mathrm{m}$ long, appear as barely resolved dots at the same magnification.

Example 2.10 (Reading a bacterium)

An electron micrograph of the gut bacterium Escherichia coli shows a rod $2\,\text{µ}\mathrm{m}$ long and $0.5\,\text{µ}\mathrm{m}$ wide: a wall, a membrane just inside it, a granular cytoplasm packed with ribosomes, and a paler central region where the single circular DNA molecule lies. No nucleus, no mitochondria. Yet the cell feeds, grows and divides every twenty minutes in a rich broth: everything the cell theory demands, in a thousandth of the volume of a cheek cell.

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