Introduction
You must first comprehend the concepts of transcription and replication in order to comprehend the issue of the Difference Between Replication and Transcription.
A cell must replicate the DNA in its genome when it divides in order for the two daughter cells to share the same genetic makeup as their mother cell. Cell division is necessary for an organism to flourish. DNA offers a straightforward replicating method. The codons of a gene are transcribed into messenger RNA during transcription, also known as RNA synthesis.
Contrary to DNA replication, transcription creates an RNA complement that always contains uracil (U) in place of thymine (T), as opposed to DNA replication.
Making copies of the DNA in a cell occurs during both transcription and DNA replication. While replication creates a second copy of the DNA, transcription converts DNA into RNA. Both procedures result in the creation of a fresh nucleic acid molecule, either DNA or RNA, but they serve quite distinct purposes—one is engaged in gene expression, while the other is involved in cell division. Despite significant basic similarities, each molecule in DNA and RNA has a particular purpose in living things.
DNA Replication vs Transcription
Every life's cornerstone is its DNA. It is essential to life itself and how it goes on. It must take some sort of sorcery to be able to produce offspring in such a way that some traits are patterned after the parents. This is valid for the processes of DNA transcription and replication, which are unique to this genetic code.
For the duplication process to occur, eukaryotes and prokaryotes both have one or more DNA polymer molecules that are copied. The efficiency of the duplication determines the outcome of DNA replication, also known as DNA synthesis.
A class of creatures known as eukaryotes has cells with nuclei. Nucleotide units make up the fundamental DNA structure of these organisms, which consists of two strands. Like two chains, the DNA double helix is organised. The two strands of DNA may be split apart, allowing the double helix to be opened, and then the two strands can be copied. Two more DNA molecules are the ultimate consequence. Then, cell division happens. The daughter cell's nucleus has a copy of the parental DNA when it is created. The strands must transport information from the parent cells to the daughter cells accurately and without mistakes.
A DNA can replicate in one of three ways. The semi-conservative model, which has been shown to be accurate among the three, involves the formation of two new molecules from a complex comprising an ageing parental and daughter strand. The conservative approach states that the parent chains persisted while two daughter strands created a new DNA double helix. Two DNA double chains were produced in dispersive form, each containing the components of a parent and daughter molecule. In humans, each replication fork replicates DNA at a rate of about 50 nucleotides per second. Due to the numerous replication fork start locations, it may be duplicated in a short period of time.
Similar to replication, but using different proteins, is transcription. A portion of double-stranded DNA is converted into single, identically stranded RNA (Transfer RNA [tRNA], Ribosomal [rRNA], and Messenger [mRNA]) during transcription. The next stage is translation, which results in the creation of a protein molecule. Only a limited fraction of DNA survives RNA processing, and only one strand is used as a template for RNA synthesis. The non-coding strand is the other strand. The enzyme RNA polymerase converts genetic information from DNA to RNA. The nucleus is where transcription happens.
DNA Facts
- The length of DNA may be extended 600 times from the earth to the sun and back.
- Watson and Crick identified the shape of a DNA molecule.
- There are 3 billion base pairs of DNA in the human genome.
- DNA research can connect you to people you never would have expected.
- All organisms share 99.99 percent of their DNA.
- DNA's two strands are duplicated during replication. From the two-stranded DNA, a single, identical RNA is created during transcription.
- Replication and transcription are mediated by many proteins.
- The outcome of transcription is a protein molecule, whereas the outcome of replication is two daughter cells.
- During transcription, DNA acts as a template for the production of RNA.
Difference Between DNA Replication and Transcription in Tabular Form
| Parameter of comparison | DNA Replication | Transcription |
| Purpose | Replication serves to preserve the whole genome for the following generation. | Making RNA copies of certain genes so that the cell may utilise them for biochemistry is the goal of transcription. |
| Definition | A DNA strand is replicated into two daughter strands, each of which includes half of the original DNA double helix. | This process is known as DNA replication. utilises the genes as templates to create a variety of useful types of RNA |
| product | One DNA strand splits into two daughter strands. | non-coding RNA, mRNA, tRNA, and rRNA ( like microRNA) |
| product processing | Complementary base pair nucleotides in eukaryotes associate with either the sense or antisense strand. | The DNA helix is then used to join them using phosphodiester links to form a full strand. Introns are spliced out, a 5' cap is inserted, and a 3' poly A tail is also added. |
| Base pairing | There are 64 potential codons since 3-letter combinations have 4 bases (43 combinations). | Transcription of RNA adheres to base pairing guidelines. By using complementary base pairing to identify the right base and link it to the original strand, the enzyme creates the complementary strand. |
| Condons | The majority of amino acids have more than one potential codon thanks to them, which encode the twenty common amino acids. The UAA, UAG, and UGA codons are the three "nonsense" or "stop" codons that indicate the end of the coding region. | Different processes are employed to duplicate the antiparallel strands of the double helix since DNA polymerases can only lengthen a DNA strand in the 5′ to 3′ orientation. Thus, the base on the old strand determines which base will be present on the new strand. |
| Result | After replication, two daughter cells are produced. | The final product of transcription is an RNA molecule. |
What is DNA Replication?
The process by which a double-stranded DNA molecule is duplicated to create two identical DNA molecules is known as DNA replication. Because every time a cell splits, the two new daughter cells must have the same genetic material, or DNA, as the parent cell, this process is crucial.
The fact that each DNA strand may act as a template for duplication is the basis of the replication process. The DNA double helix is unravelled at specified locations, known as the origin of reapplication spots, where the process starts. The subsequent synthesis of a short RNA segment known as a primer serves as the starting point for the synthesis of fresh DNA. After then, the enzyme DNA polymerase starts duplicating the DNA by matching the original bases.The RNA primers are replaced with DNA when DNA synthesis is finished. The freshly synthesised DNA segments are joined together by enzymes if there are any gaps between them.
Since DNA replication is a critical operation, the cell proofreads the freshly synthesised DNA to make sure that errors or mutations are not introduced. Following replication of the cellular DNA, the cell can divide into two daughter cells, each of which would have an exact copy of the original DNA
DNA polymerases often retain excellent fidelity because the mismatch incorporation rate is less than 1 per 107 integrated nucleotides. Students also provide a 3 to 5 foot proofreading task where they may fix any end-to-integrated mismatches. On the other hand, post-replication mismatch repair processes can fix mismatches. Less than one mistake per 109 integrated nucleotides constitutes the final incorporation rate.Artificial DNA primers and DNA polymerases that have been obtained from bacteria are used to replicate DNA in vitro. The molecular biological technology used for in vitro DNA replication is called polymerase chain reaction (PCR). Taq polymerase is the enzyme used in PCR. A pair of DNA primers are used in PCR to create DNA fragments from a known sequence.
What is Transcription?
It is a procedure by which RNA polymerase works to rewrite the genetic material found in DNA into a messenger RNA (mRNA). After leaving the cell nucleus, this mRNA serves as the building block for translating DNA.
The Transcription Process Stages
There are three key phases to the transcribing process:
- Initiation
- Elongation
- Termination
Initiation
RNA polymerase is an enzyme that facilitates the process. When it encounters a promoter sequence, which denotes the beginning of transcription, it binds to DNA and follows along with it. A DNA molecule may have many promoter sequences. Proteins called transcription factors bind to promoter regions with RNA polymerase and regulate the rate of transcription.
When RNA polymerase binds to the promoter region, it partially unravels the DNA double helix to reveal the bases on each of the two DNA strands.
Elongation
The template strand of one DNA strand, which is read from 3′ to 5′, serves as the base for the new mRNA molecule. The new mRNA's base sequence is similar to the other DNA strand, which is known as the coding strand, with the exception of the substitution of uracil for the thymine nucleotides.
RNA polymerase uses incoming ribonucleotides to construct the mRNA strand. It does this by matching complementary bases (A to U, T to A, C to G and G to C). The subsequent creation of phosphodiester bonds between neighbouring ribonucleotides is subsequently catalysed by RNA polymerase. The strand lengthens in a 5' to 3' orientation because bases may only be added to the 3′ (three-prime) end.
Termination
Up until the RNA polymerase comes across a stop sequence, elongation will proceed. The RNA polymerase now releases the DNA template, signalling the end of transcription.
With the help of transcription factors, RNA polymerase binds to the promoter to begin transcription. The unwinding double-stranded promoter's roughly 14 bases make up the transcription bubble that is created by the binding. Nucleotides are added by RNA polymerase once the transcription start site is chosen.Post-transcriptional alterations refer to the splicing of exons, polyadenylation, and 5′ end capping in eukaryotes. Non-coding RNAs, rRNAs, and tRNAs can also be made by genes, and these RNAs aid in the synthesis, control, and processing of proteins.
Difference Between DNA Replication and Transcription in Points
In order to produce new DNA and RNA strands, complementary nucleotides must bind to DNA during both DNA replication and transcription. For cell division, DNA makes two identical copies of the whole genome during DNA replication. On the other hand, transcription is the initial phase of gene expression, which results in the production of the essential proteins for cell function. Only short DNA sequences are converted into RNA during transcription. The main distinction between DNA replication and transcription is that the former entails creating a perfect copy of the genome, while the latter entails the conversion of a specific DNA segment's genetic material into RNA.
DNA Replication
The double-stranded DNA molecule is duplicated twice, creating two identical molecules. One original DNA strand makes up each of the new strands.
Transcription
Transcription uses double-stranded DNA to create a single-stranded RNA molecule.
Function
- DNA Replication: It passes on the complete genome to its progeny.
- The process of transcription produces RNA copies of a certain gene.
Enzyme Is Needed
- Topoisomerase, Helicase, DNA Primase, and DNA Ligase are involved in DNA replication.
- RNA polymerase and transcriptase are involved in transcription.
Happening During the Cell Cycle
- DNA replication takes place during the S phase of the cell cycle, when the cell is getting ready to divide.
- The cell needs to synthesise proteins when it is in the G1 and G2 stages.
Precursors of Nucleotides
- The precursors used in DNA replication include dATP, dGTP, dTTP, and dCTP.
- It uses ATP, UTP, GTP, and CTP as precursors during transcription.
Fidelity
- DNA replication: The 3′ to 5′ exonuclease activity of DNA polymerase ensures high fidelity.
- When it comes to transcription, RNA polymerase is less accurate than DNA polymerase.
The Newer Strand's length
- It creates lengthy DNA strands during DNA replication.
- Short RNA strands are synthesised during transcription.
Bond
- DNA replication: A freshly created DNA strand forms hydrogen bonds with its template.
- Transcripted RNA splits from its template during transcription.
DNA Replication Primers
DNA polymerase needs an RNA primer to start the replication process.
Primer-Less Transcription
RNA polymerase doesn't need them.
Okazaki Piece
- DNA replication: Okazaki fragments are produced by the lagging strand.
- Transcribing: With the exception of the Okazaki fragments, transcription only happens in the 5′ to 3′ direction.
Products
- DNA replication: Creation of two daughter strands.
- MRNA, tRNA, rRNA, and non-coding RNAs like microRNA are created during transcription.
- the products' fate
- DNA replication: The nucleus still contains replicated DNA.
- The majority of the product enters the cytoplasm, according to transcription.
Durability of the Products
- DNA Replication: DNA that has been replicated is passed onto offspring.
- Most RNAs are destroyed even before they begin to act during transcription.
Processing
- DNA replication: Freshly synthesised DNA is not altered.
- Post-transcriptional changes are made to transcribed RNAs.
Conclusion
Thus, it is clear how crucial DNA transcription and replication are to the maintenance of life. We also comprehended the complexity of the procedures and the whole range of chemicals and enzymes used. There is still ground-breaking research being done in this area of biology. It is a developing field that is very important in biotechnology and genetics, which has many uses in pharmaceutical and medical research.
References
- “DNA replication”. Wikipedia, the free encyclopaedia, 2017. https://en.wikipedia.org/wiki/DNA_replication. Accessed 19 Feb. 2017
- “Molecular mechanism of DNA replication”. KHANACEDAMY, 2017. https://www.khanacademy.org/science/biology/dna-as-the-genetic-material/dna-replication/a/molecular-mechanism-of-dna-replication. Accessed 19 Feb. 2017
