Name: central dogma: dna to protein
Uploaded: 2025-05-22T09:05:54.000Z
Duration: 1 min 20 s
Channel: JoVE

K12 Standards

Georgia Standards of Excellence

9-12

Biology

SB2.a

The Central Dogma

分子生物学のセントラルドグマは、DNAにコードされた情報がRNAに移され、RNAがこれらの指示に基づいてタンパク質の合成を指示すると述べています。
まず、転写の際には、DNAを鋳型としてメッセンジャーRNAやmRNAを合成します。
mRNAは、チミンがウラシルに置き換えられることを除いて、DNAのコード鎖のコピーを表しています。
次に、mRNAはリボソームによってアミノ酸の鎖に翻訳されます。
ここでは、mRNA上の3つのヌクレオチドのグループ(コドンとも呼ばれる)が、トランスファーRNAまたはtRNA分子上の相補的な配列またはアンチコドンに結合します。
各tRNAは、特定のコドンに応じて特定のアミノ酸に結合しています。
例えば、コドンCCAはプロリンに結合したtRNAに結合し、AGCはセリンに結合したtRNAに結合します。
このようにして、遺伝暗号は、得られたポリペプチド中のアミノ酸の順序を特定し、さらに処理されて機能的なタンパク質になります。

セントラルドグマ

セントラルドグマは、DNA ヌクレオチドからタンパク質のアミノ酸配列までの遺伝情報の流れを説明します。

RNA - DNA とタンパク質の間の欠けているリンク

1900 年代初頭、科学者たちは DNA が細胞機能に必要なすべての情報を保存しており、タンパク質がこれらの機能のほとんどを実行していることを発見しました。 しかし、遺伝情報を機能的なタンパク質に変換するメカニズムは長年不明のままでした。 当初、単一の遺伝子がそのコードされたタンパク質に直接変換されると考えられていました。 真核細胞における 2 つの重要な発見により、この理論に疑問が生じました。 まず、タンパク質の生成は核内では起こりません。 第二に、DNA は核の外には存在しません。 これらの発見は、DNA とタンパク質生成を結び付ける中間分子の探索のきっかけとなりました。 この中間分子は RNA であることが判明しました。

RNAは核内でDNAを鋳型として合成されます。 新しく合成された RNA は、チミンがウラシルに置き換わっている点を除いて、DNA 鎖と配列が似ています。 真核生物では、この一次転写物がさらに処理されて、タンパク質の非コード領域が除去され、5' 末端がキャッピングされ、3' 末端にポリ A 尾部が付加されて成熟 mRNA が生成され、その後細胞質に輸送されます。

冗長な遺伝子コード

真核生物ではタンパク質は20個のアミノ酸から作られます。 4 つのヌクレオチドを 3 つずつで組み合わせると、64 (4の3乗) 通りの可能なコドンが提供されます。これは、複数のコドンが個々のアミノ酸をコードできることを意味します。 したがって、遺伝コードは冗長であるか、または退化していると言われます。 常にではありませんが、同じアミノ酸を指定するコドンは、トリプレットの 3 番目のヌクレオチドのみが異なることがよくあります。 たとえば、コドン GUU、GUC、GUA、GUG はすべてアミノ酸のバリンを表します。 ただし、AUG はアミノ酸メチオニンを表す唯一のコドンです。 コドンAUGはタンパク質合成が開始されるコドンでもあるため、開始コドンと呼ばれます。 システムの冗長性により、突然変異による有害な影響が最小限に抑えられます。 たとえば、コドンの 3 番目の位置での変化は、コードされるアミノ酸を必ずしも変更しない可能性があるため、タンパク質の機能に変化は生じません。

普遍的な遺伝コード

いくつかの例外を除いて、ほとんどの原核生物と真核生物はタンパク質合成に同じ遺伝コードを使用します。 この遺伝コードの普遍性により、農業や医学の分野における科学研究の進歩が可能になりました。 たとえば、ヒトのインスリンは現在、組換え DNA 技術を使用して細菌内で大規模に製造できるようになりました。 組換え DNA 技術には、さまざまな種からの遺伝物質の使用が含まれます。 ヒトインスリンをコードする遺伝子は細菌の DNA と結合され、細菌細胞に挿入されます。 次に、細菌細胞は転写と翻訳を実行して、患者の糖尿病を治療できるヒトインスリンタンパク質を生成します。

セントラルドグマは、DNAヌクレオチドからタンパク質のアミノ酸配列への遺伝情報の流れを説明しています。
RNAは、...

Education

JoVE Core

Anatomy and Physiology

解剖生理学

Unit 1

ユニット1

Essential Cellular Processes

細胞の基本的プロセス

KEY TERMS AND CONCEPTS

主要用語と概念

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 that do most of the work in living systems.

Central Dogma: DNA to Protein

the central dogma

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

Eukaryotic DNA Copying at the Replication Fork

Eukaryotic DNA copying happens at replication forks, where the two DNA strands separate and new strands are built. This process lets a cell make an exact copy of its genetic material before it divides. The transcript explains that eukaryotic replication follows the same basic steps seen in other DNA replication systems, but it takes place in cells with a nucleus. The replication machinery works on each separated strand as a template, so the new DNA matches the original sequence. This topic is...

types of rna

RNA Types in Gene Expression

RNA types play different roles in gene expression. RNA, or ribonucleic acid, helps carry and use genetic information in cells. The main types discussed here are messenger RNA, ribosomal RNA, and transfer RNA. Messenger RNA, or mRNA, carries the genetic code from DNA to the ribosome. The ribosome is the site where proteins are made. Ribosomal RNA, or rRNA, is a key part of the ribosome itself. Transfer RNA, or tRNA, brings the correct amino acids to the ribosome during protein building. These...

transcription

Transcription and RNA Synthesis

Transcription is the process of making RNA from a DNA template. It is a key step in gene expression, because cells use the DNA sequence to build an RNA copy that can carry the message forward. During transcription, RNA polymerase binds to DNA and reads one strand as the template. The enzyme links RNA nucleotides together in the correct order to form a growing RNA molecule. This copying step does not make DNA; it produces RNA. The transcript focuses on the central idea of transcription as DNA...

translation

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...

regulation of expression at multiple steps

regulation-of-expression-at-multiple-steps

How Cells Control Gene Expression

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...

what is the cell cycle?

Cell Cycle Stages in Cell Growth

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...

mitosis and cytokinesis

Cell Division: Mitosis and Cytokinesis

Cell division depends on mitosis and cytokinesis. Mitosis is the stage when the cell’s nucleus divides and the copied chromosomes are separated into two sets. Cytokinesis is the step that follows and splits the cell into two daughter cells. These two processes work together to make sure each new cell receives genetic material and its own cytoplasm. Mitosis keeps the chromosome sets organized, while cytokinesis finishes the division of the whole cell. Together, they create two separate cells...

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

Chemical Messengers in Cell Signaling

Chemical messengers help cells communicate during signaling. These signaling molecules carry information from one cell to another and guide how cells respond. Some signaling molecules are gases, while others are proteins or peptides. Small lipids can also act as signals. In addition, cells may use steroids, amino acids, and even ions as signaling molecules. Each type of signaling molecule has different properties and works in a different way. Together, these molecules let cells send specific...

g protein-coupled receptors

G Protein-coupled Receptor Signaling

G protein-coupled receptors are a major class of cell-surface receptors. They help cells detect signals outside the cell and pass that information inward. These receptors are important in many kinds of cell communication. When a signal binds to a G protein-coupled receptor, the receptor changes shape. That change activates a G protein inside the cell. The activated G protein can then start a signaling pathway. This signaling system includes the receptor, the G protein, and the downstream...

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

Explore the central dogma and how genetic information moves from DNA to RNA to protein. Learn how transcription and translation connect genes to proteins.

Central Dogma: DNA to Protein | JoVE K12

anatomy and physiology

JoVE Core 解剖学と生理学では、人体の解剖学的および生理学的な詳細を、包括的で明確で魅力的なビデオ アニメーションで紹介します。このレッスン集は、人体の構造、コンポーネント、機能、要件に焦点を当てています。この知識を実際の医療および研究現場で応用することを実証する科学者による実際のビデオによって補完されています。

Replication in Eukaryotes

Types of RNA

Transcription

Translation

Regulation of Expression at Multiple Steps

The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. ...

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?

Meiosis I

Meiosis is the division of a diploid cell into haploid cells forming sperm and eggs in animals through differentiation. Meiosis I is the first stage of ...

Meiosis II

Meiosis II entails cell division and segregation of the sister chromatids, resulting in the production of four unique haploid gametes. The steps for ...

Crossing over

Nondisjunction

Genome Copying Errors

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Overview of DNA Repair

In order to be passed through generations, genomic DNA must be undamaged and error-free. However, every day, DNA in a cell undergoes several thousand to a ...

Base Excision Repair

One of the common DNA damages is the chemical alteration of single bases by alkylation, oxidation, or deamination. The altered bases cause mispairing and ...

RNA Editing

RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or ...

Mutations

Teratogenicity

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Mechanisms of Retrovirus-induced Cancers

Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of ...

Construct an argument based on evidence to support the claim that inheritable genetic variations may result from:New genetic combinations through meiosis (crossing over, nondisjunction), Non-lethal errors occurring during replication (insertions, deletions, substitutions), Heritable mutations caused by environmental factors (radiation, chemicals, and viruses)

SB2.b

Transgenic Plants

Recombinant DNA technology called transgenesis is often used to add a foreign gene or remove a detrimental gene from an organism. Such genetically ...

Transgenic Organisms

Overview

Transgenic organisms are genetically engineered to carry transgenes&#x2014;genes from a different species&#x2014;as part of their genome. The ...

Testing For Genetically Modified Foods

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
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Genetic Engineering of Model 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

Central Dogma: DNA to Protein

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