Name: rna types in gene expression
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

Types of RNA

Es gibt drei Arten von RNA, die eine direkte Rolle bei der Proteinsynthese spielen: Boten-RNA oder mRNA, Transfer-RNA oder tRNA und ribosomale RNA oder rRNA.
mRNA wird zunächst durch komplementäre Basenpaarung aus der DNA transkribiert. In einem mRNA-Molekül spezifizieren Codons, Gruppen aus drei Nukleotiden, die Aminosäuresequenz und geben an, wo die Proteinsynthese beginnen und aufhören soll.
Die Translation erfolgt, nachdem die mRNA in das Zytoplasma gelangt ist, wo sie mit Hilfe ihrer rRNA auf der kleinen ribosomalen Untereinheit positioniert wird.
Als nächstes bindet ein tRNA-Molekül mit einer Drei-Nukleotid-Anticodon-Sequenz an einem Ende und einer spezifischen Aminosäure am anderen Ende an ein komplementäres Codon in der mRNA.
Die korrekten tRNAs binden sequentiell an die mRNA, und die rRNA in der großen ribosomalen Untereinheit katalysiert die Bildung einer Peptidbindung zwischen zwei Aminosäuren.
Das Ribosom wandert die mRNA hinunter und bildet ein Polypeptid mit einer Sequenz von Aminosäuren, die von der mRNA spezifiziert werden.

arten von rna

Drei Haupttypen von RNA sind an der Proteinsynthese beteiligt: Messenger-RNA (mRNA), Transfer-RNA (tRNA) und ribosomale RNA (rRNA). Diese RNAs erfüllen verschiedene Funktionen und können grob in proteinkodierende und nicht-kodierende RNA eingeteilt werden. Nichtkodierende RNAs spielen eine wichtige Rolle bei der Regulierung der Genexpression als Reaktion auf Entwicklungs- und Umweltveränderungen. Nichtkodierende RNAs in Prokaryoten können manipuliert werden, um wirksamere antibakterielle Medikamente für den menschlichen oder tierischen Gebrauch zu entwickeln.

RNA erfüllt vielfältige, aber kooperative Funktionen

Das zentrale Dogma der Molekularbiologie besagt, dass die DNA die Informationen enthält, die Proteine kodieren, und dass die RNA diese Informationen nutzt, um die Proteinsynthese zu steuern.

Messenger-RNA (mRNA) ist die proteinkodierende RNA. Es besteht aus Codons – Sequenzen aus drei Nukleotiden, die eine bestimmte Aminosäure kodieren. Transfer-RNA (tRNA) und ribosomale RNA (rRNA) sind nicht-kodierende RNA. tRNA fungiert als Adaptermolekül, das die mRNA-Sequenz liest und Aminosäuren in der richtigen Reihenfolge in der wachsenden Polypeptidkette platziert. rRNA und andere Proteine bilden das Ribosom – den Sitz der Proteinsynthese in der Zelle. Während der Translation bewegen sich Ribosomen entlang eines mRNA-Strangs, wo sie die Bindung von tRNA-Molekülen stabilisieren und die Bildung von Peptidbindungen zwischen Aminosäuren katalysieren. Somit erfüllen verschiedene RNA-Typen während der Proteinsynthese spezifische, aber komplementäre Funktionen.

Nichtkodierende RNAs in Eukaryoten regulieren die Genexpression

Andere nichtkodierende RNAs als tRNA und rRNA galten zunächst als „genomischer Müll“, da sie keine Proteine kodierten. Ihre Rolle bei der Regulierung der Genexpression wurde jedoch erst in den letzten Jahrzehnten entdeckt und wird weiterhin intensiv erforscht. Aufgrund ihrer Länge können nichtkodierende RNAs in kleine regulatorische RNAs (< 100 Nukleotide) oder lange nichtkodierende RNAs (> 200 Nukleotide) eingeteilt werden.

Sowohl kleine regulatorische RNAs als auch lange nichtkodierende RNAs regulieren die Genexpression, indem sie verschiedene Phasen der Transkription und Translation verändern. Nicht-kodierende RNAs beeinflussen das mRNA-Spleißen – das Entfernen nicht-kodierender Segmente und das Zusammenfügen der proteinkodierenden Sequenzen. Auf diese Weise steuern sie die Bildung verschiedener Proteinvarianten aus einem einzigen Gen. Kleine regulatorische RNAs wie microRNAs (miRNAs) und kleine interferierende RNAs (siRNAs) binden an komplementäre Sequenzen auf der mRNA und hemmen die Proteinsynthese, indem sie entweder den Zugang der Translationsmaschinerie zur mRNA blockieren oder die mRNA selbst abbauen. Lange nichtkodierende RNAs interagieren mit Enzymen und rekrutieren diese, die DNA und Histone – Proteine, die dabei helfen, DNA in den Zellkern zu verpacken – chemisch modifizieren, um die Transkription entweder zu aktivieren oder zu unterdrücken.

Arten von RNA

An der Proteinsynthese sind drei Haupttypen von RNA beteiligt: Boten-RNA (mRNA), Transfer-RNA (tRNA) und ribosomale RNA (rRNA). Diese RNAs erfüllen vielfältige ...

Education

Lehre

JoVE Core

Anatomy and Physiology

Anatomie und Physiologie

Unit 1

Einheit 1

Essential Cellular Processes

Essentielle Zellprozesse

KEY TERMS AND CONCEPTS

KERNBEGRIFFE UND KONZEPTE

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 RNA molecules work together during protein synthesis. mRNA provides the message, rRNA helps form the protein-making machinery, and tRNA matches amino acids to the code. Understanding these RNA types helps explain how cells turn genetic instructions into proteins.

RNA Types in Gene Expression

the central dogma

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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 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

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translation

Translation: mRNA to Protein

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regulation of expression at multiple steps

regulation-of-expression-at-multiple-steps

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interphase

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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

Chemical Messengers in Cell Signaling

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g protein-coupled receptors

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cellular differentiation

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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 messenger RNA, ribosomal RNA, and transfer RNA, and see how each RNA type helps carry and use genetic information during protein synthesis.

RNA Types in Gene Expression | 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

Transcription

Translation

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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?

Meiosis I

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Meiosis II

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RNA Editing

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SB2.b

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SB2.c

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

RNA Types in Gene Expression

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