Difference Between rRNA and mRNA

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Difference Between rRNA and mRNA

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The major types of RNA (Ribonucleic acid) that cells have are rRNA or mRNA. The RNA molecule is a single-stranded structure with the bases adenine (guanine), cytosine and uracil. The pentose sugar in all RNA nucleotides is ribose. Transcription is done with the aid of the RNA polymerase enzyme to produce RNA. Although each RNA type serves a different purpose, all RNA types play a major role in protein synthesis.

rRNA vs. mRNA

The major difference between rRNA (and mRNA) is that mRNA contains the amino acid sequence for a protein's codifying instructions, while rRNA is linked with proteins to create ribosomes. The mRNA molecule is a sphere-shaped molecule, while the rRNA molecule is a linear form. The codon and anticodon sequences in rRNA are absent, while Codons can be found in mRNA.

Ribosomal RNA (or rRNA) is the fundamental component of ribosomes. These are the factories for protein synthesis. Two nucleoprotein complexes make up the 60S and 40S subunits respectively of eukaryotic-derived ribosomes. The 60s subunit of RNA is divided into 5S, 28S, and 5.8S, while the 40S subunit is 18S.

mRNA is a linear structure with a uracil-base instead of thymine. Its secondary structure could include a hairpin, stem-loop, or other structure. While tRNA is characterized by a Cloverleaf structure, which carries three stem loops, rRNA is more complex and has many loops and folds.

mRNA acts to transmit DNA; tRNA transports amino acids during protein synthesis, and rRNA is the cell's protein producer. These three RNAs are vital in transcription and protein synthesis. They are vital for all cells as, without them, life wouldn't be possible.

Messenger RNA (mRNA), is synthesized in the nucleus eukaryotes as heterogeneous nuclear RNA (hnRNA). Additionally, hnRNA processing also produces mRNA. This (mRNA), will now reach the cell and be used in the production process of proteins. Although mRNA has a short half-life, its molecular mass is high. This is the relationship between genes and proteins.

Difference Between rRNA and mRNA in Tabular Form

Parameters for Comparison rRNA mRNA
Definition The ribosomes can be formed with rRNA (also known as ribosomal RNA). After a gene has been transcribed, mRNA (or messenger RNA) is created by RNA polymerase.
Role rRNA provides the structural underpinnings for the creation of ribosomes. mRNA is responsible for transporting genetic material from the nucleus into the ribosomes.
Synthesized in Ribosome Nucleus
Size An rRNA molecule's size can vary between the 30S, 40S and 50S. Mammalian molecule sizes range from 400 to 12,000 nucleotides.
Shape The shape of rRNA is a simple sphere. The structure of mRNA can be described as linear.

The table shows some basic difference Between rRNA and mRNA. Let’s know the detailed comparison and details in the content.

RNA Features

The RNA (or ribonucleic acids) is a polymer of adenine and thymine as well as cytosine and uracil. It is made in cells by a process called translation and differs from DNA in many ways. The first is that the ribose sugars found on DNA nucleotides have a shorter hydroxyl group than RNA. This gives rise to the term deoxyribonucleic acids. This is a key modification that makes RNA more chemically reactive. Second, DNA uses thymine as a base pair with cytosine while RNA uses uracil. The third is that DNA tends to form into a helix composed of double-stranded nucleotides. Base pairs make up the "rungs” of the helical ladder. Although RNA can be found single-stranded, it is more common to form complex three-dimensional structures. This feature often confers functionality to RNA molecules.

Here are some interesting facts about RNA

  • Each RNA strand contains a sugar, a nitrogenous base, and a phosphate.
  • DNA has a double-helical structure while RNA nucleotide has a single. It could take the form of a helix and surround itself with related material to make proteins.
  • There are many types and functions of RNA. For example, decoding information can be performed by different types of RNA. Two types of RNA, tRNA (transfer RNA) and mRNA(messenger RNA) can perform different tasks.
  • Many cells make up the human body, followed by organs. Each cell contains DNA and information about genes. Only 1% of a cell contains DNA, while RNA occupies approximately 4%.
  • The DNA of a cell is only found in its nucleus. However, the RNA of the cell can be found both in its nucleus as well as in its cytoplasm.

What is rRNA?

Ribosomal RNA (or rRNA) is the fundamental component of ribosomes. The ribosomes also contain rRNAs which account for 80 per cent of total RNA in cells. The 50S and 30S subunits of ribosomes consist mainly of their own rRNA molecules. Two types of rRNAs are found in ribosomes: small rRNAs (or large rRNAs), which correspond to the large or small subunits.

The cytoplasm is where rRNAs and proteins join to form ribosomes. These ribosomes are responsible for protein synthesis. These complex structures move along the mRNA molecules during translation and help in the synthesis of amino acids to create a polypeptide chain. They interact with tRNAs and other proteins-synthesis-related molecules.

In bacteria, the small and large rRNAs have approximately 1500 and 3000 nucleotides respectively, while they have around 1800 and 5000 in humans. However, ribosomes are consistent in their function and structure across all species. rRNA does not contain anticodons or codons. Two ribosomal units that arrange ribosomal DNA (SSU), are the large ribosomal and short ribosomal Subunits (LSU) There are different rRNA types that were used to make the subunits. The catalysis of protein production begins when tRNA is placed between the LSU and SSU.

The nucleolus is a special region in the cell nucleus that synthesizes rRNA molecules. It appears as a dense part of the nucleus and houses the genes that encode the rRNA. The encoded rRNAs can be classified as either small or large. Every ribosome has at least one large and one small rRNA. The nucleolus is where the large and the small rRNAs are combined with ribosomal protein to form large and small subunits. (E.g., the 50S in bacteria and the 30S in yeast). These subunits are generally named according to the rate of sedimentation in Svedberg units [S] in a centrifugal force. Ribosomal proteins are synthesized within the cytoplasm and then transported to the nucleus where they can be sub-assembled in the nucleus. For final assembly, the subunits are returned to the cytoplasm.

Definition of rRNA

The primary factor in ribosomes is ribosomal RNA, or rRNA. These are factories for protein production. Two nucleoproteins complexes make up the eukaryotic subunits of the nucleoproteins complexes the 60S and 40S. The 60s subunit can be further broken down into 5S, 28S, and 5.8SRNA, while the 40S subunit has 18SRNA.

It is unclear what rRNAs do in ribosomes. It is believed that RNA molecules travel into the cytoplasm to bind with other rRNA molecules and proteins, forming ribosomes.

Ribosomal RNA is also known as rRNA. The cell's rRNA contains 80% of total RNA. Two subunits make up ribosomes. The 50s subunit is larger and the 30s subunit smaller.

  • Each one is composed of its own rRNA molecules. The nucleolus is the organelle that synthesizes rRNA molecules.
  • The cytoplasm is made up of rRNAs that combine with enzymes, proteins and proteins to create ribosomes. These structures travel along the mRNA in translation to aid in the assembly of amino acid chains to make a polypeptide chain.

What is mRNA?

mRNA, or messenger RNA, is the result of an RNA polymerase-transcribed gene and serves as a link between the gene and the protein. The amount of mRNA found in cells is only 5%. mRNA is the most varied form of RNA in terms of nucleotide structure and sequence. It also contains complementary genetic code, in the form of codons. These are triplets of nucleotides that were copied from DNA during transcription.

Each codon codes for an amino acid. However, the same amino acids might be coded by multiple codons. Only 20 of 64 possible codons, or triplet bases, in the genetic code, correspond with amino acids. Three stop codons are also present in the genetic code, which indicates that ribosomes have to stop translating proteins.

As part of the post-transcriptional process, the 5' end mRNA of eukaryotes is capped by a guanosine Triphosphate nucleotide. This aids in mRNA recognition during translation and protein synthesis. To slow down enzymatic degradation, several adenylate residues can be added to the 3' of an mRNA. Both the 5' and 3’ ends of an mRNA contribute to its stability to the other.

Additionally, mRNA molecules can have different bases in their inner structures, such as 6-methyladenylates. These mRNA molecules also contain an intron that would be spliced before the complete mRNA molecule is formed.

Definition of mRNA

In eukaryotes, the synthesis of messenger RNA or mRNA occurs in the nucleus as heterogeneous RNA (hnRNA). Further, hnRNA is processed to release mRNA. This (mRNA), will now enter the cytoplasm and participate in protein synthesis.

mRNA has a very short half-life and a high molecular mass. These are known as the link between genes or proteins. This form of RNA, or the eukaryotic modified RNA, is only used to prevent hydrolysis by 5’-exonucleases. These are then capped by 7-methylguanosine Triphosphate at the 5'-terminal end. This helps to recognize the mRNA necessary for protein synthesis.

Also known as messenger RNA, mRNA can also be called messenger RNA. 5% of total RNA in a cell is made up of mRNA. mRNA is the most heterogeneous type of RNA. It differs in its base sequence and in its size. mRNA copies DNA's complementary genetic information during transcription in the form of triplet codons.

  • Although there are 64 triplet bases or codons in the genetic code; only 20 codons contain the amino acids. These codons contain 3 stop codons that stop the process of protein synthesis during translation.
  • The 5' end of mRNA in eukaryotes is sealed with guanosine triphosphate nucleotide during post-transcription. This helps to recognize mRNA in translation and protein synthesis.
  • Multiple adenylate residues (or poly-A tails) have been added to the 3' end, which help prevent enzymatic degrading. Both ends are stable, as can be seen.

mRNA tRNA and rRNA Functions

These are the functions of mRNA, tRNA, and rRNA:

  • The transcription process produces mRNA, which is the genetic information carried by the gene from the nucleus into the ribosome within the cytoplasm.
  • Together with the proteins, rRNA composes the ribosomes. These organelles are responsible for protein synthesis.
  • During translation, tRNA is used to transfer amino acids to the nucleus.

What are the similarities between rRNA and mRNA?

  • There are two types of RNA: rRNA and mRNA.
  • Both are vital as they play a role in protein synthesis.
  • Both contain ribonucleotides.
  • Both are also found in the cytoplasm.

Difference Between rRNA and mRNA in Points

Here are some of the principal Difference Between rRNA and mRNA:

  1. rRNA (or ribosomal RNA) is used to create ribosomes. mRNA, which is also known as messenger RNA is created by RNA Polymerase from the transcript gene.
  2. The structural basis of ribosome production is rRNA, while mRNA transports genetic information from the nucleus into the ribosomes to aid in protein synthesis.
  3. The ribosome synthesizes rRNA, while the nucleus synthesizes mRNA.
  4. The rRNA molecule is a sphere-shaped (complex structure), while the mRNA molecules are a linear shape.
  5. Codon sequences and anticodon are absent in rRNA; codons are found in mRNA.
  6. Mammals have a range of sizes for mRNA molecules. tRNA molecules can be as large as 76 to 90 nucleotides. rRNA's size may differ from the 30S, 40S or 60S.
  7. The mRNA has a linear shape. The tRNA has a cloverleaf shape. RRNA has a sphere shape (complex).


Ribosomal RNA (rRNA), a type of large RNA, is essential for the development of ribosomes. The ribosome, a protein-synthesizing cell organelle that transforms an mRNA molecular's coding sequence to a polypeptide chain, is known as the ribosome. The nucleolus is the place where rRNA is synthesized. The two types of rRNA molecules that are produced are small rRNA and large rRNA. However, messenger RNA molecules (mRNA), which transport a transcript from a gene that encodes a functional protein, move from the nucleus to ribosomes. Transcription is how mRNA is made. The in-charge of transcription is RNA polymerase. The ribosome is home to the rRNA molecule which acts as the translation organelle. An mRNA molecular is a form of RNA that transports part of the DNA code to other parts of the cell.


  1. https://www.sciencedirect.com/science/article/pii/S1097276509002706
  2. https://sfamjournals.onlinelibrary.wiley.com/doi/abs/10.1111/j.1462-2920.2010.02415.x


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"Difference Between rRNA and mRNA." Diffzy.com, 2024. Sat. 11 May. 2024. <https://www.diffzy.com/article/difference-between-rrna-and-mrna-299>.

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