Transcription vs Translation in DNA
Transcription and translation are the steps through which a functional protein is synthesized from the genetic material, DNA. These processes are found to occur both in prokaryotes as well as eukaryotes.
This is the synthesis of RNA chain. This RNA sequences forms the template for formation of proteins. 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 with ribosugars as their pentose sugar moiety.
The whole process of complementary base pairing is catalyzed as well as monitored by the enzyme RNA polymerase. The transcription process occurs in the direction of 5’ to 3’. The resultant sequence which is essentially a replica of the parental DNA strand, called as the coding strand. The coding strand is complementary to the other strand called the template or antisense strand.
Each unit of transcription encodes for a single gene in eukaryotes. The resultant RNA strand in transcription is called as the primary transcript. The first base pair is called the start unit. The process continues until it reaches the terminator sequence
This is the process which follow transcription event. The primary transcript is translated into a sequence of corresponding aminoacids forming a peptide chain. These undergo further processing and folding to form the final fully functional proteins. Translation is the process of making peptide strands from primary transcript.
There are a set of aminoacids which are carried to the site of translation by specific transfer RNAs for the process. Apart from this messenger RNAs and ribosomal RNAs also play significant roles in translation.
Comparison: Transcription vs. Translation in DNA
Precursor molecule – For transcription the DNA is the parental strand where as for translation it is the primary transcript (RNA).
Function- Transcription produces an RNA molecule complementary to the DNA strand where as translation produces the peptide sequence which is complementary to the RNA (same as the DNA sequence).
Regulation- Transcription is highly regulated by internal mechanisms based on chromatin structure, histones, DNA methylation etc in eukaryotes and operon mechanisms. The operon regulation involves promoter sequences/ activators and suppressors which are found in the sequence.
Translational control is mainly through regulation of binding of ribosomal subunits to the translation complex. Most naturally occurring antibiotics, toxins and drugs target this process.
Post event modifications – Transcriptional product undergoes splicing and dicing events. This removes the intragenic portions (introns) which are non coding in nature.
Post translational modifications are mainly chemical in nature attaching functional groups to the peptide sequence.
Enzymes- A single RNA polymerase is found to be capable of carrying out and controlling the transcription in prokaryotes and three such enzymes are at work in eukaryotes.
Translation requires several enzymes and factors for the process. It has mainly three steps, initiation, elongation and termination each of which requires a set of RNAs, cofactors and enzymes.
Site- Transcription generally occurs in the nucleus where the transcription factors and enzymes are available. Translation on the other hand occurs in the cytoplasm after the primary mRNA transcript is transferred from the nucleus to the cytoplasm.
The events transcription and translation can be considered as two consecutive processes in production of a functional protein. Both events are controlled by different factors and enzymes but eventually work toward the same goal. Though the regulation, mechanism and other factors differ both are targets for drug designing since they are being controlled by rigorous mechanisms.