Regulation of Gene Expression · 基因表达的调控
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| gene expression/dʒiːn ekˈspreʃn/ | 基因表达 | jī yīn biǎo dá |
| transcription factors/trænˈskrɪpʃn ˈfæktəz/ | 转录因子 | zhuǎn lù yīn zi |
Not all genes on at once
- Your genome holds tens of thousands of genes.
- But a cell never needs all of them working at the same time.
- So it switches genes on and off as required.
- Controlling which genes are used is called gene regulation.
不是所有基因同时开着
- 你的基因组容纳着成千上万个基因。
- 但细胞从不需要它们全部同时工作。
- 所以它按需要开启和关闭基因。
- 控制哪些基因被使用,叫做基因调控。
Genes are switched on and off
- Gene expression 基因表达 is a gene being read to make its protein.
- A gene can be switched on (expressed) or off (silent).
- An off gene is still in the DNA — it is just not being used.
- Regulation decides which genes are on in each cell, at each moment.
基因被开启和关闭
- 基因表达(gene expression)是一个基因被读取以制造它的蛋白质。
- 一个基因可以被开启(表达)或关闭(沉默)。
- 一个关闭的基因仍然在 DNA 里——它只是不被使用。
- 调控决定每个细胞里、每个时刻哪些基因是开着的。
Gene expression means… · 基因表达意味着……
Gene expression is a gene being used — transcribed and translated to make its protein. · 基因表达是一个基因被使用——被转录和翻译以制造它的蛋白质。
A cell keeps every one of its genes switched on all the time. · 细胞让它的每一个基因一直开着。
A cell expresses only the genes it needs right now; the rest are switched off. · 细胞只表达它现在需要的基因;其余的被关闭。
Transcription factors flip the switch
- Transcription factors 转录因子 are proteins that bind to DNA.
- They decide whether RNA polymerase can transcribe a gene.
- Some help switch a gene on; others switch it off.
- A signal from outside can activate these factors, turning genes on in response.
转录因子拨动开关
- 转录因子(transcription factors)是结合到 DNA 上的蛋白质。
- 它们决定 RNA 聚合酶能否转录一个基因。
- 有些帮助开启一个基因;另一些把它关闭。
- 来自外面的一个信号能激活这些因子,作为响应开启基因。
Switching a gene on · 开启一个基因
Step through how a signal turns a gene on - only then is its protein made. · 一步步走过一个信号如何开启一个基因——只有那时它的蛋白质才被制造。
Proteins that bind DNA to switch genes on or off are called transcription . · 结合 DNA 以开启或关闭基因的蛋白质叫做转录。
Transcription factors control whether RNA polymerase can transcribe a gene. · 转录因子控制 RNA 聚合酶能否转录一个基因。
Why regulation matters
- Making every protein all the time would waste huge amounts of energy.
- Regulation lets a cell make only what it needs, right when it needs it.
- It also lets a cell respond to changes in its environment.
- In bacteria, groups of related genes share a switch called an operon.
调控为什么重要
- 一直制造每一个蛋白质会浪费巨量的能量。
- 调控让细胞只制造它需要的,恰在它需要的时候。
- 它还让细胞对环境的变化做出响应。
- 在细菌里,一组相关的基因共享一个叫做操纵子的开关。
Why is regulating gene expression useful? · 调控基因表达为什么有用?
Regulation lets a cell make the right proteins at the right time — efficient and responsive. · 调控让细胞在正确的时间制造正确的蛋白质——高效且有响应力。
Select all · 所有 true statements about gene regulation. · 选出关于基因调控的所有正确说法。
A switched-off gene is still there in the DNA — it is just not expressed. The other three are correct. · 一个被关闭的基因仍然在 DNA 里——它只是不被表达。其余三条正确。
Almost every cell in your body holds the same genes. Cells differ not in which genes they have, but in which are switched on. A muscle cell and a nerve cell run different genes from the very same genome.
你身体里几乎每个细胞都持有相同的基因。细胞的不同不在于它们有哪些基因,而在于哪些被开启。一个肌肉细胞和一个神经细胞从同一个基因组运行着不同的基因。
A bacterium and its food:
- The bacterium E. coli keeps the genes for digesting lactose switched off.
- When lactose appears, those genes are switched on and the enzymes are made.
- When the lactose is gone, the genes switch off again — no waste.
一个细菌和它的食物:
- 大肠杆菌把消化乳糖的基因保持关闭。
- 当乳糖出现时,那些基因被开启,酶被制造出来。
- 当乳糖没了,基因又关闭——没有浪费。
Gene expression is a gene being used to make its protein, and cells control it through gene regulation. Transcription factors switch genes on or off, so a cell makes only the proteins it needs. Every cell has the same genes; they differ in which are expressed.
基因表达是一个基因被使用以制造它的蛋白质,细胞通过基因调控来控制它。转录因子开启或关闭基因,所以细胞只制造它需要的蛋白质。每个细胞都有相同的基因;它们的不同在于哪些被表达。