- 12 Reasons To Know Why DNA is Better than RNA
- 1. DNA is more stable than RNA
- 2. DNA is a better chemical unit of heredity than RNA
- 3. DNA mutates slower than RNA
- 4. DNA has smaller grooves than RNA
- 5. DNA can self-replicate, RNA is synthesized from DNA
- 6. DNA is stable in alkaline conditions, RNA isn’t so much stable
- 7. DNA is double-stranded, RNA is single-stranded
- 8. DNA is a long polymer, RNA is a short polymer
- 9. DNA determines genetic coding
- 10. DNA is directly responsible for metabolic activities, evolution, heredity, variation, and differentiation
- 11. DNA makes genes and chromosomes
- 12. DNA is able to express the information when needed
Why is DNA Better than RNA? DNA is better than RNA because DNA is more stable, permanent, hereditary chemical units, better genetic information storehouse, and is less reactive as compared to RNA. DNA is both more resilient and more easily repaired than RNA.
DNA stands for Deoxyribonucleic acid whereas, RNA stands for Ribonucleic acid. Both are polymers of nucleotides.
With the exception of certain viruses (ex: retroviruses), DNA rather than RNA carries the hereditary genetic code in all biological life on Earth.
Both are genetic materials, nucleic acids, help in gene expression, somewhat similar in structure, and they both are dependent on each other.
Both DNA and RNA are made up of nucleotides. Each nucleotide is composed of a nitrogenous base, a five-carbon pentose sugar, and a phosphate group.
So, what’s the catch? Although both DNA and RNA seems to be similar, there are some reasons why DNA is always better than the RNA.
Never the less, if you see, DNA is much-much better as the genetic information storehouse of the cell as compared to that of RNA.
Let’s know more about why DNA is better than RNA…
12 Reasons To Know Why DNA is Better than RNA
1. DNA is more stable than RNA
The structure of the DNA is made up of two strands. Each strand is composed of many nucleotides. Therefore it’s said a polynucleotide.
Each nucleotide is made up of a Deoxyribose Pentose Sugar, a Nitrogenous Base, and a Phosphate group.
The structure of the DNA is very stable due to the presence of strong covalent bonds between pentose sugar, and hydrogen bonds between nitrogenous bases of the two strands.
Moreover, in the structure, if you see the hydrogen bonds are strengthened and protected from solvent hydration by the hydrophobic stacking of the bases. Thus, giving the double-strand huge stability.
And moreover, the deoxyribose pentose sugar in the backbone of each DNA strand does not have a hydroxyl group (OH) on the 2′ position. This also makes it even more stable as compared to RNA.
2. DNA is a better chemical unit of heredity than RNA
Heredity simply means the transferring of physical or mental characteristics genetically from one generation to another.
But, what makes heredity possible? It’s the presence of DNA, not RNA because DNA can make RNA.
DNA due to its ability of replication and super packaging can compress itself.
It is mostly seen during the cell division when the DNA and its genetic information get packed/compressed in the form of chromosomes and get passed to the next generation.
Moreover, DNA due to its double-strand nature is highly stable and protected. And, this keeps the genetic information preserved and better protected for a longer period of time as compared to that of RNA.
DNA is the long-term storage of information that is good for heredity.
Till today, DNA is carrying the genetic information from generation after generation, as it was passed by our ancestors with little modifications in it.
So, that’s why it is said that DNA is a better chemical unit of heredity than RNA.
3. DNA mutates slower than RNA
The mutation is a permanent alteration in the DNA base sequence of a person, such that the sequence differs from what is found in most people or from its parents.
What’s so interesting is that DNA stability doesn’t allow itself to mutate rapidly. RNA being unstable can mutate rapidly.
In our DNA, slow mutations occur over a lifetime, changing the sequence of bases: A, C, G, and T a little bit. This results in changes in the proteins that are made during gene expressions a little bit.
Mutations can occur during DNA replication if errors are made and not corrected in time.
But, the interesting thing is that the DNA proofreading and repair mechanisms save the DNA from being mutated very fast if somehow enough mutation has occurred. This helps keeps the genes intact with only fewer changes.
This is one big advantage of DNA that mutation occurs slowly as the DNA molecule is very stable. And also the DNA proofreading and repair mechanisms are always in an active mode to protect it.
This is good for evolution as evolution supports slow mutational changes.
4. DNA has smaller grooves than RNA
Another awesome thing about DNA in terms of molecular biology is that DNA has smaller grooves (both major and minor), which makes it harder for enzymes to “attack.”
But, if you compare this with RNA then you’ll find that RNA has larger grooves, which makes it easier to be “attacked” by enzymes.
As the double-helix of DNA is very stable, the destructive enzymes cannot get enough place to cut or cleave the DNA. Moreover, the grooves are small so they don’t get enough space to attach to the DNA as well.
Another interesting thing is that the smaller grooves of DNA can be taken by the protective enzymes which don’t give enough space for the destructive ones to do their job.
This makes DNA better and protects structure more and more and so keep the genetic information intact.
5. DNA can self-replicate, RNA is synthesized from DNA
Another important advantage of the DNA double helix is that DNA can replicate itself because of its complementary base pairing between the two strands of polynucleotide chains.
This ensures that when the DNA strands separate to replicate and so an exact copy is created.
DNA needs to be replicated because we get only one copy of DNA from each of our parents via. gametes. The gametes when unite to fertilize and form a zygote then the one maternal and one paternal DNA copies get stored in the zygote.
The zygote has the only DNA (diploid) of the offspring. Now, when the zygotes divide to form an embryo, that only diploid DNA is copied from one cell to another as it is necessary for every cell to get the DNA copies of both of the parents.
This is only possible because the DNA can self-replicate of its own. And when the need arises for gene expression, the replicated DNA creates mRNA which then creates the proteins.
So, that’s one reason why it is said that DNA can self-replicate, and RNA is synthesized from DNA which is actually a very big advantage.
6. DNA is stable in alkaline conditions, RNA isn’t so much stable
The absence of (OH) hydroxyl group on the 2′ position of Deoxyribose Pentose sugar makes DNA more stable than RNA as it cannot give free hydrogen at high pH alkaline solution.
Unlike DNA, the presence of (OH) hydroxyl group on the 2′ position of Ribose Pentose sugar in RNA can give up a hydrogen ion to the solution at high pH alkalinity, creating a highly reactive alkoxide ion that attacks the phosphate group holding two neighboring nucleotides together.
This results in the breakdown of RNA while enjoying the remarkable stability of DNA in high alkaline pH.
As healthy cells have a slightly alkaline internal environment with a pH of around 7.2. Therefore, the stability of DNA in an alkaline solution makes it better than RNA.
Moreover, histones that are present in DNA are alkaline (basic) in nature. The highly basic nature of histones not only helps in the DNA-histone interactions but also contributes to their water solubility in an alkaline environment as well.
7. DNA is double-stranded, RNA is single-stranded
DNA being double-stranded has a lot of advantages to it, as compared to that of RNA.
The double-stranded structure of the DNA can coil and super-coil of its own to fit within a size inside the living cell’s nucleus. This allows the DNA to be tightly packed inside the chromosome.
The double-stranded structure of the DNA can also facilitate proper self-replication to form more DNA copies, and also causes proper transcription to form mRNA.
Another advantage is that the balance between the covalent bonds and the hydrogen bonds makes the DNA very stable by stabilizing the various physical and chemical interactions within itself and its surroundings.
Moreover, it gives the ability to the DNA to be more water-soluble in nature. And also, it doesn’t allow the DNA structure to mutate rapidly.
Considering these above factors, DNA due to its double-stranded structure is much better than the RNA which is single-stranded.
8. DNA is a long polymer, RNA is a short polymer
Both DNA and RNA are polymers of nucleotides. The thing is that DNA is a long polymer, whereas RNA is a short polymer.
A single DNA polymer in each chromosome can have four types of nucleotides repeated billions of times. That’s how long a DNA polymer can be.
Whereas, a single RNA polymer can have four types of nucleotides repeated hundreds to thousands of times. That’s how small an RNA polymer is as compared to the DNA polymer.
The requirement for a long DNA polymer is very necessary as the DNA needs to contain the whole set of genetic information the living body needs to have and inherit.
Whereas, it is okay for the RNA to be a short polymer as the RNA is only synthesized from the long DNA polymer when needed to code for a particular protein or when needed to do other jobs in the cell.
So, that’s why DNA being a long polymer is an advantage over RNA.
9. DNA determines genetic coding
Genetic Code is the sequence of nucleotides in deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) that determines the amino acid sequence for the formation of proteins.
So when the DNA is inherited from the parents, the nucleotide sequence that is the genetic coding of the offspring is represented the same as that of the parent. No genetic coding RNA is inherited in any means.
DNA is considered the supreme and the prime one because the genetic code is presented in the DNA first in any living organisms (excluding viruses).
The genetic code is protected in the DNA, and this code is translated to the mRNA version, which then only, can be translated to proteins whenever the need arises.
So, we can say that DNA determines genetic coding and the RNA simply transcribes what is provided by the DNA.
That’s another reason why DNA is better than RNA.
10. DNA is directly responsible for metabolic activities, evolution, heredity, variation, and differentiation
DNA is directly responsible for metabolic activities, evolution, heredity, variation, and differentiation. Let’s understand why.
The DNA contains the genetic information of any living organism. It contains the information to run all the cellular metabolic activities.
Moreover, the DNA also contains the evolutionary details of any living organism encoded in it. Till today, DNA is carrying the genetic information from generation after generation, as it was passed by our ancestors.
Our chromosomes are inherited from our mother and father and this process has been continuing generation after generation. The chromosomes are always made up of DNA.
The property of the recombination of two sections of DNA (genes) via. crossing-over indicates hows the variation takes place when the genes are passed from one generation to the other. This literally shows the variation and differentiation of each and every person from each other.
If DNA is directly then, RNA is indirectly responsible for metabolic activities, evolution, heredity, variation, and differentiation of the living organisms.
As, RNA is synthesized from the DNA and does what the DNA directs it to do.
11. DNA makes genes and chromosomes
DNA not just has the coiling capacity but the supercoiling capacity as well. This is what makes DNA stand apart from the RNA.
Chromosomes are made up of very long DNA strands that are wrapped around proteins.
In other words, Chromosome is the supercoiled, tightly packaged, and compressed structure of long DNA strands.
If you talk about the order of packaging, then DNA→Genes→Chromosome. This means that DNA coils itself to make Genes, and Genes further supercoils itself to produce Chromosomes.
A supercoiled DNA molecule is smaller in size than a chromosome. It’s because a chromosome is made up of a long chain of DNA molecules that can have about 249 million DNA building blocks (base pairs).
12. DNA is able to express the information when needed
Remembered the Central Dogma of Molecular Biology. It states the two-step process properly viz. transcription and translation, by which the information in genes flows into proteins: DNA→RNA→Protein.
It proves the genetic nature of DNA and shows how DNA is able to self-replicate and transcript to mRNA.
mRNA with the use of ribosomes and tRNA is able to translate the required proteins in the process further.
It shows that genetic information cannot be transferred among proteins, or from proteins to nucleic acids.
And that, only DNA is able to express itself whenever needed by producing mRNA and then the required proteins.