Maarg Manthan · Topic 10.3

Types of RNA and Their Technological Applications

Science & Technology › Biotechnology – Principles and Techniques · Topic 10.3

RNA, or ribonucleic acid, is a single-stranded nucleic acid that carries and uses the information in DNA. The main types are messenger RNA, which carries the code for a protein, transfer RNA, which brings amino acids, and ribosomal RNA, which forms the protein factory called the ribosome. Small regulatory RNAs, such as microRNA and small interfering RNA, switch genes off through RNA interference, which was shown by Andrew Fire and Craig Mello in 1998. RNA technology gave messenger RNA vaccines against COVID-19, antisense and RNA interference drugs, and the guide RNA used in CRISPR gene editing.

5 min read · UPSC Prelims · Science & Technology · Biotechnology – Principles and Techniques

At a Glance

Coding RNA Messenger RNA
Helper RNAs tRNA and rRNA
Regulatory RNAs miRNA and siRNA
RNAi discovery Fire and Mello, 1998
Big use mRNA vaccines
Exam link UPSC Prelims, Science & Technology: Biotechnology – Principles and Techniques

Where Does It Fit?

This topic follows genomics and proteomics. It explains the different RNA molecules that sit between genes and proteins, and how technology uses them. Previous topic: Genomics and Proteomics. Next topic: Genome Sequencing and Its Practical Uses.

What Are the Main Types of RNA?

Type	Role
Messenger RNA (mRNA)	Copies the code of a gene and carries it to the ribosome to make a protein
Transfer RNA (tRNA)	Brings the matching amino acid to the ribosome by reading the code in groups of three bases
Ribosomal RNA (rRNA)	A main part of the ribosome and helps to join amino acids
MicroRNA (miRNA)	Short RNA of about 22 bases that binds mRNA and reduces its translation
Small interfering RNA (siRNA)	Short double stranded RNA that guides cutting of a matching mRNA
Long non-coding RNA	Long RNAs that do not code for proteins but regulate genes
Guide RNA	A short RNA that leads the Cas enzyme to its DNA target in CRISPR

How Is RNA Used in Technology?

mRNA vaccines: a lipid nanoparticle carries synthetic mRNA that makes a viral protein in the body and trains immunity. The COVID-19 vaccines of Pfizer-BioNTech and Moderna were the first widely used. Katalin Kariko and Drew Weissman received the 2023 Nobel Prize in Physiology or Medicine for base modifications that made this possible
RNA interference drugs: siRNA drugs silence disease genes. Patisiran, approved in 2018, was the first
Antisense oligonucleotides: short strands that bind mRNA to block or correct it, used for conditions such as spinal muscular atrophy
CRISPR: guide RNA directs gene editing, as in Gene Editing (CRISPR) and Gene Therapy
RNA in crops: RNA interference can protect plants from viruses and insects without a foreign protein
Diagnostics: RT-PCR reads RNA of viruses, as in Polymerase Chain Reaction (PCR)
RNA sequencing: reading which genes are active in a cell
Ribozymes: RNA molecules with enzyme activity, which support the idea of an RNA world before DNA

What Else Should You Remember?

Differences from DNA: RNA has ribose sugar, the base uracil in place of thymine, and is mostly single stranded
Central dogma: DNA is copied to RNA by transcription and RNA is read to make protein by translation
Reverse transcription: retroviruses such as HIV copy RNA into DNA using reverse transcriptase
RNA interference: Andrew Fire and Craig Mello received the Nobel Prize in 2006 for this discovery
Stability: RNA is fragile, so vaccines need lipid coats and cold storage
India: Indian companies and the Department of Biotechnology have worked on mRNA vaccine platforms. Check the current status of approvals before quoting
Related topic: the Nobel Prize in Chemistry 2020 went to Emmanuelle Charpentier and Jennifer Doudna for CRISPR
Safety: side effects, delivery to the right tissue and the cost of RNA drugs remain issues
Codon: a group of three bases in mRNA that codes for one amino acid. There are 64 codons, 61 for amino acids and three stop signals
Capping and tail: mRNA in higher cells gets a cap at one end and a poly-A tail at the other, which protect it and help translation
Spliceosome: introns are removed from the first RNA copy before it becomes mature mRNA
Viral genomes: coronaviruses and influenza viruses store their genes as RNA, so their vaccines and tests often target RNA
Delivery: lipid nanoparticles, which protect fragile RNA and help it enter cells, were a key advance for both mRNA vaccines and siRNA drugs

Why Does It Matter for the Exam?

Match type with role: mRNA carries code, tRNA brings amino acids, rRNA builds ribosome
Technology: mRNA vaccine, RNAi, antisense drug, guide RNA
Nobel links: RNAi in 2006 and mRNA vaccines in 2023
Current affairs link: new RNA based medicines and vaccine platforms
Common errors: saying RNA has thymine or that an mRNA vaccine changes human DNA

As an analytical point, RNA technology works fast because a new target needs only a new sequence. The challenge is delivery and cost, so public funding of platforms matters for access.

Why Is This Topic Important?

Types Basic match questions
Technology Vaccines and drugs
Nobel Fire and Mello, Kariko

What Came Next?

The next topic covers reading the full sequence of genomes and the uses of such knowledge. Next topic: Genome Sequencing and Its Practical Uses.

Key People and Terms

mRNA Messenger of the gene
tRNA Amino acid carrier
rRNA Part of ribosome
miRNA Short gene regulator
RNAi RNA interference
Uracil RNA base for thymine

Exam Corner

Points to Remember

RNA base: uracil.
RNAi discovered: 1998, Nobel 2006.
mRNA vaccine pioneers: Kariko and Weissman (2023).
miRNA length: about 22 bases.
First siRNA drug: patisiran (2018).

Do Not Confuse With

mRNA and miRNA Protein code versus gene regulator
siRNA and miRNA Perfect match cut versus partial match block
mRNA vaccine and DNA vaccine RNA message versus DNA plasmid

Memory Hook

Messenger carries, transfer fetches, ribosomal builds; micro and small ones switch the genes off.

Mains Angle

Questions ask about the uses and limits of RNA technology. These points help.

Uses Vaccines and drugs
Limits Delivery and cost
India Platform building

A Question You May Face

An original practice question, not a past paper question.

“Explain the types of RNA and discuss the significance of RNA based technologies such as mRNA vaccines and RNA interference.”

How to Answer

Types mRNA, tRNA, rRNA, small RNAs.
Uses Vaccines, RNAi drugs.
Limits Delivery, cost.
Way Platforms and access.

GS Relevance

Prelims: types of RNA, RNA interference, mRNA vaccines, applications. GS Paper 3: science and technology, biotechnology, health.

Frequently Asked Questions

What are the main types of RNA?

The main types are messenger RNA, which carries the code for a protein, transfer RNA, which brings amino acids to the ribosome, and ribosomal RNA, which forms part of the ribosome. Small regulatory RNAs such as microRNA and small interfering RNA control gene activity.

What is RNA interference?

RNA interference is a natural process in which small RNA molecules, such as small interfering RNA, guide the cutting or blocking of a matching messenger RNA, so that the gene is silenced. Andrew Fire and Craig Mello discovered it in 1998 and received the Nobel Prize in 2006.

How does an mRNA vaccine work?

An mRNA vaccine delivers a synthetic messenger RNA inside a lipid nanoparticle into body cells, which then make a harmless viral protein. The immune system learns to recognise this protein and responds quickly to the real virus. The mRNA does not enter the nucleus or change human DNA.

Who won the Nobel Prize for mRNA vaccine research?

Katalin Kariko and Drew Weissman received the 2023 Nobel Prize in Physiology or Medicine for discoveries about nucleoside base modifications that allowed effective mRNA vaccines. Their work reduced the inflammatory reaction to synthetic mRNA and made vaccines such as those against COVID-19 possible.

What is the role of guide RNA in CRISPR?

In CRISPR gene editing, the guide RNA is a short RNA molecule that matches a chosen DNA sequence and leads the Cas enzyme to that site. The enzyme then cuts the DNA, allowing a gene to be disabled or corrected. Changing the guide RNA changes the target.

PYQ Practice — Statement Analysis

1 RNA contains the base thymine.

False

It contains uracil.

2 Transfer RNA brings amino acids to the ribosome.

True

By reading the code.

3 RNA interference was discovered by Fire and Mello.