Name: translation: mrna to protein
Uploaded: 2023-06-23T15:38:45.000Z
Duration: 1 min 31 s
Channel: JoVE

K12 Standards

Georgia Standards of Excellence

9-12

Biology

SB2.a

Translation

翻译是以信使RNA为模板合成蛋白质的过程。
该过程始于核糖体小亚基与甲硫氨酸tRNA及起始因子形成复合物后，结合到mRNA的5′端。该复合物沿mRNA从5′端向3′端扫描，直至遇到作为翻译起始位点的AUG密码子。
接着，甲硫氨酸tRNA与AUG密码子配对，并招募核糖体的大亚基。当携带相应氨基酸的tRNA通过其反密码子与mRNA上的下一个密码子结合时，新蛋白质的合成即开始。
这一作用使新氨基酸靠近先前掺入的氨基酸，两个氨基酸之间形成肽键。
核糖体沿着序列移动到下一个密码子时，翻译继续进行。这种向前移动称为转位，将持续进行，直到核糖体遇到终止密码子为止。
终止密码子的独特之处在于它们没有对应的tRNA。相反，一类称为释放因子的蛋白质会结合到终止密码子上，促使核糖体释放新合成的蛋白质，并导致核糖体解离。

翻译

翻译是从信使RNA (mRNA) 携带的遗传信息合成蛋白质的过程。转录后，它构成了基因表达的最后一步。这个过程由核糖体执行，核糖体是蛋白质和特殊RNA分子的复合物。核糖体、转运 RNA (tRNA) 和其他蛋白质产生一条氨基酸链——多肽——作为翻译的最终产物。

翻译产生生命的基石

蛋白质被称为生命的基石，因为它们构成了所有生物体的绝大多数组成部分——从肌肉纤维到头发，再到免疫系统的组成部分——而每个这些蛋白质的蓝图都由每个细胞中DNA中的基因编码。生物学的中心法则表明，遗传信息通过转录和翻译过程转化为功能蛋白。

翻译发生在细胞核外

真核生物有一个膜结合的细胞核，其中 mRNA 从 DNA 转录而来 转录后，mRNA被运送到细胞核外，被翻译成氨基酸链（多肽），并最终成为功能性蛋白质。这可以发生在细胞质或粗面内质网中，其中多肽被进一步修饰。相反，原核生物缺乏核区室，因此原核生物的翻译发生在细胞质中，而 mRNA 仍在转录。

mRNA中的密码子序列决定多肽序列

mRNA 中的每个密码子对应于细胞储存的 20 个氨基酸之一，以及不编码氨基酸的终止密码子。另一种 RNA 分子，转运RNA (tRNA)，负责在翻译过程中根据密码子序列向核糖体提供正确的氨基酸。在 tRNA 分子的一端，称为氨酰基-tRNA 合成酶的酶将特定氨基酸共价连接到附着位点，而位于 tRNA 另一端的反密码子序列确保将正确的氨基酸递送到核糖体。一些 tRNA 分子能够结合多个密码子序列，从而实现编码的多功能性（称为摆动效应）。这是因为与前两个核苷酸相比，tRNA 分子对 mRNA 密码子序列中第三个核苷酸的结合特异性较低。

一些遗传性疾病源于翻译缺陷

翻译是一个复杂的过程，依赖于多种细胞成分。影响这个多样化工具包任何部分的突变都可能导致疾病。例如，铁储存疾病高铁蛋白血症，也称为白内障综合征，是由 mRNA 5' 非翻译区突变引起的，该区域对于招募翻译起始蛋白非常重要。这些突变导致铁蛋白的异常高翻译率，导致其在受影响患者的血液和组织中积聚。结果，眼睛的晶状体变得混浊。其他疾病与编码 tRNA 和核糖体亚基的基因突变有关。例如，骨髓疾病 Diamond-Blackfan 贫血源于 RPS19 基因的突变，RPS19 基因是小核糖体亚基的一个组成部分。

翻译是利用信使RNA（mRNA）携带的遗传信息合成蛋白质的过程。在转录之后，它构成了……

Education

教育

JoVE Core

Anatomy and Physiology

解剖学与生理学

Unit 1

第 1 单元

Essential Cellular Processes

细胞基本过程

KEY TERMS AND CONCEPTS

关键术语与概念

译本

translation: mrna to protein

Translation is the step in gene expression where ribosomes use messenger RNA, or mRNA, to build a protein. The mRNA sequence carries the instructions copied from DNA. During translation, those instructions are read in order so the cell can make a specific chain of amino acids.

This process depends on the ribosome and transfer RNA, or tRNA. The ribosome reads the mRNA, and tRNA brings the matching amino acids. As the chain grows, the amino acids are linked together to form a polypeptide, which is the start of a protein.

Translation is a key part of how cells use genetic information. It connects the message in mRNA to the final protein product. Understanding translation helps explain how genes lead to the molecules that cells need to function.

Translation: mRNA to Protein

the central dogma

Central Dogma: DNA to Protein

The central dogma explains how genetic information flows in cells from DNA to RNA to protein. It is a core idea in molecular biology and helps show how genes influence cell function. DNA stores the instructions. During transcription, a cell copies a gene into RNA, which is a related nucleic acid. That RNA message can then be used in translation to build a protein. Proteins carry out many jobs in cells and help determine traits. The central dogma links the genetic code in DNA to the molecules...

replication in eukaryotes

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types of rna

RNA Types in Gene Expression

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transcription

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translation

Translation is the step in gene expression where ribosomes use messenger RNA, or mRNA, to build a protein. The mRNA sequence carries the instructions copied from DNA. During translation, those instructions are read in order so the cell can make a specific chain of amino acids. This process depends on the ribosome and transfer RNA, or tRNA. The ribosome reads the mRNA, and tRNA brings the matching amino acids. As the chain grows, the amino acids are linked together to form a polypeptide, which...

regulation of expression at multiple steps

regulation-of-expression-at-multiple-steps

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Cells control gene expression at several stages, from making RNA to building protein. These checkpoints include transcription, RNA processing, RNA localization, and translation. Together, they help decide when a gene is used and whether a protein is made. Transcription is controlled by regulatory proteins. Transcription factors, activators, and repressors can start or slow the transcription of genes. After transcription, the cell makes a precursor RNA, also called pre-mRNA. Pre-mRNA must be...

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The cell cycle is the process that controls cell growth and division. It explains how one cell makes two new cells. This process helps cells grow and reproduce.

interphase

Interphase and Cell Growth

Interphase is the part of the cell cycle when a cell grows and prepares to divide. It is a major stage of the cell cycle, and it comes before cell division begins. During interphase, the cell carries out its normal functions. It also copies its DNA so each new cell can receive a full set of genetic material. The cell may also build up the materials it needs for division. Interphase is not a single step. It includes phases such as G1, S, and G2, which help the cell grow, copy DNA, and get...

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the cell cycle control system

Cell Cycle Checkpoints and Cyclin Control

The cell cycle is controlled by checkpoints that help a cell move from one phase to the next and begin mitosis. This control system uses internal regulatory molecules and outside signals to send stop or advance instructions. It makes sure each step is finished before the cell moves forward. Cyclins and cyclin-dependent kinases, or Cdks, are the main regulators of the cell cycle. They act during the G1, G2, and M phases. These regulators work at specific checkpoints to keep cell division...

molecular factors affecting cell division

molecular-factors-affecting-cell-division

Cell Cycle Regulators That Control Division

Cell division is controlled by outside signals and by internal cell cycle regulators. Nearby cell death can encourage division, and human growth hormone (hGH) can also promote it. In contrast, too little hGH or crowded cells can slow or stop division. Inside the cell, regulator molecules help each stage finish correctly before the next stage begins. Some regulators act directly on the cycle, while others affect the activity or production of other regulatory proteins. These molecules can either...

what is meiosis?

Meiosis and the Formation of Gametes

Meiosis is the cell division process that forms gametes, or sex cells. It reduces the chromosome number so offspring can inherit the correct amount of genetic material. This process includes two successive divisions. First, one cell divides, and then the resulting cells divide again. These steps separate the genetic material in a controlled way. Meiosis helps explain how sexual reproduction passes traits from one generation to the next. It is a key topic in high school biology because it...

overview of cell signaling

Cell Signaling Pathways and Responses

Cell signaling pathways and responses help cells communicate and react to changes. Cells send signals to one another, and those signals can trigger a specific response in the target cell. A signal usually begins when a signaling molecule reaches a cell with the right receptor, which is a protein that receives the message. The receptor helps the cell recognize the signal and start the communication process. Inside the cell, the message can move through a signaling pathway. This pathway passes...

types of signaling molecules

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g protein-coupled receptors

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cellular differentiation

From Stem Cell to Specialized Cells

Cellular differentiation turns unspecialized cells into specialized cells with specific jobs. This process helps a complex organism, such as a human, develop from a single fertilized egg into a body with many cell types. Nerve cells, muscle cells, and epithelial cells are examples of the final cell types that appear during development. A zygote is the first cell after fertilization. It is a totipotent stem cell, which means it has very high differentiation potential and can form all cell types...

key terms and concepts

Learn how translation uses mRNA, ribosomes, and tRNA to build a polypeptide chain from amino acids and turn genetic information into protein.

Translation: mRNA to Protein | JoVE K12

anatomy and physiology

JoVE Core Anatomy and Physiology showcases the anatomical and physiological details of the human body in comprehensive, clear, and engaging video animations. This collection of lessons focuses on the structures, components, functions, and requirements of the human body. It is complemented by scientist-in-action videos that demonstrate the application of this knowledge in real-world medical and research settings.

The Central Dogma

Replication in Eukaryotes

Types of RNA

Transcription

Regulation of Expression at Multiple Steps

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Construct an explanation of how the structures of DNA and RNA lead to the expression of information within the cell via the processes of replication, transcription, and translation

What is Meiosis?

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Meiosis II

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Crossing over

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Base Excision Repair

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RNA Editing

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Mutations

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SB2.b

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Transgenic Organisms

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Ask questions to gather and communicate information about the use and ethical considerations of biotechnology in forensics, medicine, and agriculture

SB2.c

Obtain, evaluate, and communicate information to analyze how genetic information is expressed in cells

Translation: mRNA to Protein

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