The key difference between transcription and translation in DNA is that transcription is the production of an mRNA sequence which contains the genetic code encoded in the coding sequence of the gene while translation is the production of a functional protein using the genetic code encoded in the mRNA sequence.
Gene expression is the process of producing a functional protein using the genetic information hidden in the gene. It occurs via two major events: transcription and translation. Hence, transcription and translation are the steps through which a functional protein is synthesized from the genetic material. Both transcription and translation occur in prokaryotes as well as in eukaryotes. The article intends to discuss the difference between transcription and translation in DNA.
CONTENTS
1. Overview and Key Difference
2. What is Transcription in DNA
3. What is Translation in DNA
4. Similarities Between Transcription and Translation in DNA
5. Side by Side Comparison – Transcription vs Translation in DNA in Tabular Form
6. Summary
What is Transcription?
Transcription is the first stage of gene expression in which an mRNA sequence results from a DNA template. Here, the mRNA sequence serves as the template for translation, which is the second stage of gene expression which results in a functional protein. In transcription, complementary bases get attached to the DNA sequence and these, in turn, are bonded with phosphoric acid bonds forming the RNA. Unlike the parental DNA sequence, the resultant RNA chain consists of nucleotides composed of ribosugars as their pentose sugar moiety.
Moreover, the enzyme RNA polymerase catalyzes and monitors the whole process of complementary base pairing during transcription. Furthermore, the transcription process occurs in the direction of 5’ to 3’. The resultant sequence is a replica of the parental coding DNA sequence. And, this coding strand is complementary to the other strand, which is called the template or antisense strand.
Figure 01: Transcription
Each unit of transcription encodes for a single gene in eukaryotes. The resultant RNA strand in transcription is the primary transcript, which is premature RNA. We call the first base pair the start unit. And, this process continues until it reaches the terminator sequence of the gene. The resulting mRNA sequence then leaves the nucleus and travels to the cytoplasm for the next stage.
What is Translation?
Translation is the second or the final stage of gene expression which follows the transcription event. The primary transcript is translated into a sequence of corresponding amino acids, forming a peptide chain. These undergo further processing and folding to form the final fully functional proteins. Hence, translation is the process of making peptide chains from the primary transcript.
Figure 02: Translation
Translation process involves three types of RNA. They are mRNA, tRNA, and rRNA. They carry out different functions, but all these functions are essential for the final product of the translation process. tRNA carries a set of amino acids to the site of translation according to the correct genetic code order of the mRNA sequence. rRNA assembles and processes the amino acids into a peptide chain within the ribosomal two subunits. Likewise, with the corporate functions of all three RNAs, translation results in a functional protein at the end of the process.
What are the Similarities Between Transcription and Translation in DNA?
- Transcription and translation are two steps of the gene expression process.
- Both processes involve mRNA.
- Also, both processes are equally essential in order to produce proteins in living organisms.
- Besides, both need a template in order to produce the product.
- Moreover, both processes need building blocks of each macromolecule.
What is the Difference Between Transcription and Translation in DNA?
Transcription is the first step of gene expression which copies the genetic information encoded in the DNA template into an mRNA sequence while translation is the second step of gene expression which produces a functional protein from the genetic information encoded in the mRNA sequence. So, this is the key difference between transcription and translation in DNA. In eukaryotes, transcription occurs inside the nucleus while the translation occurs in the cytoplasm at ribosomes. However, in prokaryotes, both transcription and translation occur in the cytoplasm. Thus, this is also a significant difference between transcription and translation in DNA.
Moreover, a further difference between transcription and translation in DNA is the template each process use. Transcription uses a DNA template while translation uses an mRNA template. Besides, the main raw material of transcription is ribonucleotides while the main raw material of translation is amino acids. Therefore, we consider this also as a difference between transcription and translation in DNA.
The following infographic presents more details on the difference between transcription and translation in DNA comparatively.
Summary – Transcription vs Translation in DNA
The events transcription and translation are two consecutive processes in the production of a functional protein. Both events are controlled by different factors and enzymes, but they work towards the same goal. Though the regulation mechanism and other factors differ between both processes, both are targets for drug designing since they are being controlled by rigorous mechanisms. In eukaryotes, transcription occurs inside the nucleus while the translation occurs in the cytoplasm at ribosomes. In prokaryotes, both transcription and translation occur in the cytoplasm. Transcription uses a DNA template while translation uses an mRNA template. Furthermore, transcription yields an mRNA sequence while translation yields a functional protein. Thus, this summarizes the difference between transcription and translation in DNA.
Reference:
1. “Overview of Transcription.” Khan Academy, Available here.
2. “Translation: DNA to mRNA to Protein.” Nature News, Nature Publishing Group, Available here.
Image Courtesy:
1. “Protein synthesis” By Kelvinsong – Own work (CC BY 3.0) via Commons Wikimedia
2. “Process of transcription (13080846733)” By Genomics Education Programme – Process of transcription (CC BY 2.0) via Commons Wikimedia