Name: dna to protein: central dogma steps
Uploaded: 2020-11-23T11:47:33.000Z
Duration: 1 min 25 s
Channel: JoVE

K12 Standards

Minnesota Academic Standards in Science

9-12

Life Science

1.1.1 9L.1.1.1.1

The Central Dogma

分子生物学の中心的な定説は DNAにコード化された情報が RNAに転送され 次にこれらの指示に基づいて RNAがタンパク質の 合成を指示するとしています まず転写の過程で チミジンがウラシルによって置換されている点を除いた コード鎖のコピーを表す伝令RNA(mRNA)を 合成する鋳型としてDNAが用いられます 次に真核生物の翻訳過程で mRNAがリボソームに移動します ここでmRNAにある ３つのヌクレオチド基のコドンは 転移RNAの相補的配列の tRNA分子に結合し その各々は特定のコドンに応じて 特定のアミノ酸に付着します 例えばコドンCCAは プロリンに付着したtRNAに結合し AGCはセリンに付着した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でアミノ酸が配列される 順序を特定します 次いでしばしば ポリペプチドはさらに処理されて 機能的タンパク質になります

「DNAとタンパク質産生の関係を発見する」 Nature Education 1 no. 1 (2008):112。[<a href="https://www.nature.com/scitable/topicpage/discovering-the-relationship-between-dna-and-protein-27699" target="__blank">ソース</a>]

ラルストン、エイミー、ケナ・ショー「遺伝暗号を読む」 ネイチャーエデュケーション 1 no. 1 (2008):120。[<a href="https://www.nature.com/scitable/topicpage/reading-the-genetic-code-1042" target="__blank">出典</a>]

セントラルドグマ

<h4>概要</h4
 
 生物学のセントラルドグマは、DNAにコード化された情報がメッセンジャーRNA（mRNA）に伝達され、mRNAがタンパク質の合成を指示するというものです。このmRNAの塩基配列をアミノ酸に変換するための命令を「遺伝情報（遺伝暗号）」と呼びます。この遺伝情報の普遍性が、科学研究、農業、医療の発展につながっています。
 
 <h4>RNAはDNAとタンパク質をつなぐミッシングリンクです</h4>
 
 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格納し、タンパク質がその機能のほとんどを担っていることを発見しました。しかし、遺伝情報が機能的なタンパク質に変換されるメカニズムは、長年にわたって解明されていませんでしました。当初は、1つの遺伝子がそのコード化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。しかし、真核細胞における2つの重要な発見が、この理論に疑問を投げかけました。1つ目は、タンパク質の生成は核の中では行われないこと、2つ目は、DNAは核の外には存在しないことです。これらの発見により、DNAとタンパク質の生成をつなぐ中間分子の探索が始まりました。核と細胞質の両方に存在し、タンパク質の生成に関係する中間分子、それがRNAです。
 
 転写の際には、DNAを鋳型として核内でRNAが合成されます。真核生物では、この一次転写産物をさらに加工し、タンパク質非コード領域を取り除き、5’末端をキャップし、3’ポリAテールを追加してmRNAを作成し、細胞質へと運びます。
 
 <h4>mRNAの配列を解釈するためのルールが遺伝暗号を構成します</h4>
 
 翻訳は、細胞質内のリボソームで行われ、mRNAにコード化された情報がアミノ酸の鎖に翻訳されます。3つのヌクレオチドが1つのアミノ酸をコードしており、この3つのヌクレオチドの並びをコドンと呼びます。どのコドンが特定のアミノ酸を指定するかを示す一連の規則が、遺伝暗号を構成しています。 
 
 <h4>遺伝暗号は冗長です</h4>
 
 真核生物では、20種類のアミノ酸からタンパク質が作られます。4つのヌクレオチドを3つセットで組み合わせると、64（43）個のコドンが可能になります。つまり、1つのアミノ酸が複数のコドンでコードされる可能性があるということです。このため遺伝暗号は、冗長であるまたは縮退していると言われます。多くの場合、同じアミノ酸を指定するコドンは、コドンの3番目のヌクレオチドだけが異なるが、必ずしもそうではないです。例えば、GUU、GUC、GUA、GUGというコドンは、いずれもアミノ酸のバリンを表します。しかし、AUGはアミノ酸のメチオニンを表す唯一のコドンです。AUGは、タンパク質の合成を開始するコドンでもあり、開始コドンと呼ばれています。システムの冗長性は、突然変異の有害な影響を最小限に抑えます。これは、コドンの3番目の位置に変異（＝変化）があっても、必ずしもアミノ酸が変化するとは限らないからです。
 
 <h4>遺伝暗号は万能です</h4>
 
 一部の例外を除いて、ほとんどの原核生物と真核生物は、同じ遺伝暗号を使ってタンパク質を合成しています。この遺伝暗号の普遍性が、科学研究、農業、医療の発展を可能にしました。例えば、ヒトのインスリンはバクテリアで大規模に製造できるようになりました。これには組換えDNA技術が使われています。組換えDNAは、異なる種の遺伝物質から構成されています。ヒトインスリンをコードする遺伝子をバクテリアのDNAと結合させ、バクテリアの細胞に挿入します。細菌細胞は転写と翻訳を行い、組換えDNAにコードされたヒトインスリンを生成します。できあがったヒトインスリンは、糖尿病の治療に用いられます。

概要

生物学のセントラルドグマは、DNAにコードされた情報がメッセンジャーRNA(mRNA)に転送され、メッセンジャーRNA(mRNA)が合成を指示すると述べています...

Education

JoVE Core

Molecular Biology

分子生物学

Unit 1

ユニット1

DNA, Cells, and Evolution

DNA、細胞、そして進化

KEY TERMS AND CONCEPTS

主要用語と概念

dna to protein: central dogma steps

The central dogma explains how genetic information moves from DNA to RNA to protein. This flow is a key idea in molecular biology. It helps show how cells use genes to make the molecules that carry out work.

DNA stores the instructions for making proteins. During transcription, a gene in DNA is copied into RNA. The RNA then carries that message to the next stage.

In translation, the RNA message is used to build a protein. Proteins do much of the cell’s work, so this process connects genes to traits and cell function. Understanding the central dogma helps students see how information in DNA becomes an active product in the cell.

DNA to Protein: Central Dogma Steps

the dna helix

DNA Structure and Base Pairing

DNA has a helical structure that helps store genetic information. The double helix is the shape formed by two strands that twist around each other. This structure is a key feature of DNA in cells. The two strands are held together by base pairing. Bases on one strand match with bases on the other strand in a regular way. This pairing helps keep the DNA molecule stable and organized. The helix shape also helps explain how DNA fits into chromosomes and carries instructions for living things. By...

the central dogma

The central dogma explains how genetic information moves from DNA to RNA to protein. This flow is a key idea in molecular biology. It helps show how cells use genes to make the molecules that carry out work. DNA stores the instructions for making proteins. During transcription, a gene in DNA is copied into RNA. The RNA then carries that message to the next stage. In translation, the RNA message is used to build a protein. Proteins do much of the cell’s work, so this process connects genes to...

prokaryotic cells

Inside Prokaryotic Cell Structure

Prokaryotic cells have a simple internal structure compared with many other cells. They are usually divided into two groups: bacteria and archaea. These cells have no nucleus, so their DNA is not enclosed in a membrane-bound compartment. Instead, the genetic material is found in the nucleoid, a region where the DNA is located in the cell. Some prokaryotic cells also contain plasmids, which are small extra DNA molecules. A capsule may surround the cell and provide an additional outer layer. <br...

eukaryotic compartmentalization

Cell Compartments in Eukaryotes

Eukaryotic cells use compartments to organize many different jobs inside one cell. These compartments help separate processes so they can happen in the right place. The compartment called the cytosol is the fluid part of the cell. It surrounds the other internal structures and helps support many cell processes. Inside the cell, membrane-bound organelles create distinct microenvironments. A microenvironment is a small internal space with conditions that fit a specific task. This separation...

the tree of life - bacteria, archaea, eukaryotes

the-tree-of-life-bacteria-archaea-eukaryotes

How Life Is Classified Into Three Domains

The tree of life shows how organisms are related through evolution. Its root represents the common ancestor of all life on Earth. From that point, branches spread out like a tree. The tips of the branches represent living, or extant, species. Species that no longer exist, called extinct species, appear closer to the center of the tree. Today, these organisms are grouped into three domains: bacteria, archaea, and eukaryotes. Scientists still debate these divisions, so the tree of life keeps...

mutations

How Mutations Change DNA

Mutations are changes in DNA. They can alter the genetic code and affect how genes work. In high school biology, students often study mutations to understand how DNA changes can influence traits. The transcript focuses on two common mutation types: point mutations and frameshift mutations. A point mutation changes one nucleotide, which is one DNA building block. A frameshift mutation happens when nucleotides are added or removed and the reading frame shifts. These changes matter because they...

gene evolution - fast or slow?

Why Some Gene Regions Evolve Faster

Gene regions do not all change at the same rate. In eukaryotes, long stretches of DNA do not code for proteins or RNAs. Some of these non-coding regions include important regulatory sequences, but most have no known function. Because little or no selection pressure acts on them, they often change the fastest over evolutionary time. Protein-coding regions usually evolve more slowly. A change in a coding sequence can alter a protein and make it less effective at doing its job. That creates...

genome size and the evolution of new genes

genome-size-and-the-evolution-of-new-genes

How Genome Size Shapes New Genes

Genome size can vary widely, and it also helps show how new genes form. Every living organism has a genome, whether it uses RNA or DNA. Yet the size of that genome can be very different from one organism to another. One major difference is whether the organism is prokaryotic or eukaryotic. Prokaryotic genomes usually have little to no non-coding sequence, which means genes are packed closely together in operons along the chromosome. Eukaryotic genomes contain long stretches of non-coding DNA...

gene families

How Gene Families Evolve and Diversify

Gene families are groups of genes that are thought to come from a shared ancestor. They usually form when a gene is copied by mistake during cell division. The original gene stays under selection pressure to keep its job, while the extra copy can change more quickly over time. Some copied genes gain a new role in the organism. When that happens, they are called paralogs, which are two genes in the same species that evolved from one common ancestral gene. Gene families also include orthologs,...

types of genetic transfer between organisms

types-of-genetic-transfer-between-organisms

How Genes Move Within and Across Generations

Genetic transfer is the movement of genetic information from one organism to another. It happens in two main ways: vertical gene transfer and horizontal gene transfer. Vertical gene transfer moves genes from one generation to the next. It is much more common than horizontal gene transfer. Vertical gene transfer happens during both sexual reproduction and asexual reproduction. In both cases, one or more organisms pass some or all of their genome to their offspring. This kind of transfer occurs...

key terms and concepts

Learn how genetic information moves from DNA to RNA to protein through transcription and translation, and how this process helps cells make proteins.

DNA to Protein: Central Dogma Steps | JoVE K12

molecular biology

JoVE Core 分子生物学は、明確で簡潔なアニメーション ビデオ レッスンを通じて細胞の分子プロセスを紹介します。さらに、科学者の実際のビデオでは、これらの概念の応用が現代の研究室での実際の実験を通じて実証されています。

new-jersey-student-learning-standards-for-science

New Jersey Student Learning Standards for Science

High School

heredity-inheritance-and-variation-of-traits

Heredity: Inheritance and Variation of Traits

HS-LS3-1

Next Generation Science Standards

from-molecules-to-organisms-structures-and-processes

From Molecules to Organisms: Structures and Processes

HS-LS1-1

new-york-state-science-learning-standards

New York State Science Learning Standards

Structure and Function

HS-LS1-1.

myJoVE Corporation

The DNA Helix

DNA Packaging

DNA as a Genetic Template

Two structural features of the DNA molecule provide a basis for the mechanisms of heredity: the four nucleotide bases and its double-stranded nature. The ...

Organization of Genes

Lampbrush Chromosomes

In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, R&#252;ckert observed LBCs in shark egg cells and coined the ...

Polytene Chromosomes

Polytene chromosomes are giant interphase chromosomes with several DNA strands placed side by side. They were discovered in the year 1881 by Balbiani in ...

Euchromatin

The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions ...

Heterochromatin

Heredity: Inheritance and Variation of Traits: Ask questions to clarify relationships about the role of DNA and chromosomes in coding the instructions for characteristic traits passed from parents to offspring. (P: 1, CC: 2, CI: LS3)

1 Exploring phenomena or engineering problems
 1.1 Asking questions and defining problems
  1.1.1 Students will be able to ask questions about aspects of the phenomena they observe, the conclusions they draw from their models or scientific investigations, each other’s ideas, and the information they read.

DNA to Protein: Central Dogma Steps

Description

Transcript

Tags

More videos by Standards