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

هناك ثلاثة أنواع من الحمض النووي الريبي لها دور مباشر في تخليق البروتين - الحمض النووي الريبي المرسال أو الرنا المرسال ، ونقل الحمض النووي الريبي أو الحمض النووي الريبي ، والحمض النووي الريبي الريبوسومي أو الحمض النووي الريبي.
يتم نسخ mRNA لأول مرة من الحمض النووي عن طريق الاقتران الأساسي التكميلي. في جزيء الرنا المرسال ، تحدد الكودونات ، وهي مجموعات من ثلاثة نيوكليوتيدات ، تسلسل الأحماض الأمينية وتشير إلى المكان الذي يجب أن يبدأ فيه تخليق البروتين ويتوقف عنه.
تحدث الترجمة بعد انتقال الرنا المرسال إلى السيتوبلازم ، حيث يتم وضعه على الوحدة الفرعية الريبوسومية الصغيرة بمساعدة الحمض النووي الريبي الريبوزي.
بعد ذلك ، يرتبط جزيء الحمض النووي الريبي ، مع تسلسل مضاد للكودون ثلاثي النوكليوتيدات على أحد طرفيه وحمض أميني معين من جهة أخرى ، بكودون تكميلي في mRNA.
ترتبط الحمض النووي الريبي الصحيح بالحمض النووي الريبي المرسال بالتتابع ، ويحفز الرنا الريبي المرسال في الوحدة الفرعية الريبوزومية الكبيرة تكوين رابطة ببتيد بين اثنين من الأحماض الأمينية.
ينتقل الريبوسوم إلى أسفل الرنا المرسال مكونا عديد ببتيد مع سلسلة من الأحماض الأمينية المحددة بواسطة mRNA.

أنواع الحمض النووي الريبي

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تشارك ثلاثة أنواع رئيسية من الحمض النووي الريبوزي (RNA) في تركيب البروتين: الحمض النووي الريبي المرسال (mRNA)، والحمض النووي الريبي الناقل (tRNA)، والحمض النووي الريبي الريبوسومي (rRNA). تؤدي هذه الـ RNAs وظائف متنوعة ويمكن تصنيفها على نطاق واسع على أنها RNA مُشفرة للبروتين أو RNA غير مُشفرة. تلعب RNAs غير المشفرة أدوارًا مهمة في تنظيم التعبير الجيني استجابةً للتغيرات التنموية والبيئية. يمكن التلاعب بالـ RNAs غير المشفر في بدائيات النوى لتطوير أدوية مضادة للجراثيم أكثر فعالية للاستخدام البشري أو الحيواني.

يؤدي الحمض النووي الريبوزي (RNA) وظائف متنوعة ولكنها تعاونية

تنص العقيدة المركزية للبيولوجيا الجزيئية على أن الحمض النووي (DNA) يحتوي على المعلومات التي تشفر البروتينات، ويستخدم الحمض النووي الريبوزي (RNA) هذه المعلومات لتوجيه تركيب البروتين.

الرنا المرسال (mRNA) هو الرنا المخلق للبروتين. يتكون من كودونات وهو يتألف من تسلسل كودونات من ثلاثة نيوكليوتيدات ترمز إلى حمض أميني معين. أما الحمض النووي الريبوزي الناقل (tRNA) والحمض النووي الريبوزي الريبوسومي (rRNA) فهما حمضان نوويان ريبوزيان غير مشفران. يعمل الحمض النووي الريبوزي الناقل (tRNA) كجزيء محول يقرأ تسلسل الحمض النووي الريبوزي المرسال (mRNA) ويضع الأحماض الأمينية بالترتيب الصحيح في سلسلة عديد الببتيد النامية. rRNA وبروتينات أخرى تشكل الريبوسوم، وهو مقر تركيب البروتين في الخلية. أثناء الترجمة، تتحرك الريبوسومات على طول شريط الحمض النووي الريبوزي (mRNA) حيث تقوم بتثبيت ارتباط جزيئات الحمض النووي الريبي (tRNA) وتحفز تكوين روابط ببتيدية بين الأحماض الأمينية. وهكذا، تؤدي أنواع مختلفة من الحمض النووي الريبوزي وظائف محددة ولكنها متكاملة أثناء تركيب البروتين.

الأحماض النووية الغير مشفرة (mRNAs) تنظم التعبير الجيني في حقيقيات النوى

تم اعتبار RNAs غير المشفرة بخلاف tRNA و rRNA في البداية "خردة جينومية" لأنها لا تقوم بتشفير البروتينات. ومع ذلك، فقد تم اكتشاف أدوارها في تنظيم التعبير الجيني على مدى العقود القليلة الماضية وما زالت قيد البحث على نطاق واسع. بناءً على طولها، يمكن تصنيف RNAs غير المشفرة على أنها RNAs تنظيمية صغيرة (أقل من 100 نيوكليوتيدات) أو RNAs طويلة غير مشفرة (أكثر من 200 نيوكليوتيدات).

ينظم كل من الـ RNA التنظيمي الصغير والـ RNA التنظيمي الطويل غير المشفران التعبير الجيني عن طريق تغيير مراحل مختلفة من النسخ والترجمة. تؤثر RNAs غير المشفرة على ربط mRNA، أي إزالة الأجزاء غير المشفرة والانضمام إلى تسلسلات ترميز البروتين. وبهذه الطريقة، يتحكمون في تكوين متغيرات بروتينية مختلفة من جين واحد. ترتبط RNAs التنظيمية الصغيرة مثل الرنا الميكروي (miRNAs) والرنا المتداخل الصغير (siRNAs) بالتسلسلات التكميلية على الرنا المرسال (mRNA) وتمنع تركيب البروتين إما عن طريق منع وصول آلية الترجمة إلى الرنا المرسال أو عن طريق تحطيم الرنا المرسال نفسه. تتفاعل RNAs الطويلة غير المشفرة و تقوم بتجنيد الإنزيمات التي تقوم بالتعديل كيميائيا للحمض النووي والهستونات - البروتينات التي تساعد على تجميع الحمض النووي في النواة - ، إما لتنشيط النسخ أو تثبيطه.
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تشارك ثلاثة أنواع رئيسية من الحمض النووي الريبي في تخليق البروتين: الحمض النووي الريبي المرسال (mRNA) ، ونقل الحمض النووي الريبي (tRNA) ، والحمض النووي الريبي الريبوسومي (rRNA). تؤدي هذه الحمض النووي الريبي ...

Education

JoVE Core

Anatomy and Physiology

التشريح وعلم وظائف الأعضاء

Unit 1

الوحدة الأولى

Essential Cellular Processes

العمليات الخلوية الأساسية

KEY TERMS AND CONCEPTS

المصطلحات والمفاهيم الأساسية

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

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

Eukaryotic DNA Copying at the Replication Fork

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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

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regulation of expression at multiple steps

regulation-of-expression-at-multiple-steps

How Cells Control Gene Expression

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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

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the cell cycle control system

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molecular factors affecting cell division

molecular-factors-affecting-cell-division

Cell Cycle Regulators That Control Division

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what is meiosis?

Meiosis and the Formation of Gametes

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overview of cell signaling

Cell Signaling Pathways and Responses

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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

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?

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Meiosis II

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Crossing over

Nondisjunction

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RNA Editing

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Mutations

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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

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Transgenic Organisms

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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

Description

Transcript

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