Definition of Transcription
- Transcription is the process by which the genetic information contained on DNA strands is transferred into an RNA strand through an array of polymerization reactions caused by enzymes known as DNA-dependent polymerases.
- This is the very first stage of gene expression in which the information is transferred between structures to the next.
- In the process of transcription, molecules of RNA get created, lengthened and finally elongated. The RNA that is formed is non-genetic RNA.
- Transcription is an essential step for translation. It occurs in the event of a requirement for a specific gene product at a particular time to the specific tissue.
- One strand of DNA is called the template strand, gets duplicated during transcription, as resulting RNA strands form mono-stranded messenger-RNA (mRNA).
- The transcription of a gene takes place at the chromosomal end of the gene. This is typically a small portion of the chromosome.
- The transcription process is controlled by a sophisticated process that is controlled and catalyzed by the enzyme DNA-dependent RNA polymerase.
- The initial step is identification of DNA sequences, also known as promoter sequences which indicate the start in the development of the gene.
- The process is followed by the splitting of two DNA strands and the replication of one of the DNA strands using the polymerase in RNA.
- The RNA polymerase that is found in the eukaryotes is more complex and different as compared to prokaryotes.
- The sequence that is created after replication is identical to that of the original template since the process is based on the complementary principles of base pairing in DNA however, the thymine element is replaced by uracil.
- In prokaryotes the entire process is controlled by proteins which function as operators or signals and stop this process through physically blocking RNA polymerase after the process has been completed.
- In eukaryotes the various proteins referred to as transcription factors play a role in the control of transcription.
- In addition, post-transcriptional modifications is also seen in eukaryotes in which the pre-mRNA (the product from transcription) is altered through the method of splicing prior to the mature mRNA gets to the ribosomes that are used for translation.
- The mRNA produced functions as an outline for the synthesis of proteins during transcription.
- Based on the DNA sequence that is used to be used for transcription, rRNA as well as tRNA synthesis can also take place.
- Transcription takes place inside the nucleus of the eukaryotes, and in the cells of prokaryotes in which the enzymes and transcriptional factors are present.
- It is blocked by antibiotics, such as rifampicin or 8-Hydroxy.
- The process is detected using methods like RT-PCR DNA microarray, in situ hybridization, as well as northern blotting.
- The process of translation is of protein synthesis, where the RNA information is expressed as polypeptide chains.
- It is the second and final step in the process of expression of genes where information encoded in the mRNA sequence result in the amino acid sequence.
- The beginning point to translation begins with the microRNA that has formed through the process of transcription of a specific DNA sequence. Translation follows transcription.
- Although the information contained in the mRNA is used to make the amino acid sequence other types of RNA, such as the tRNA are also necessary to complete the process.
- As with transcription, translation can also be controlled by a variety of factors and enzymes. The most crucial enzyme is aminoacetyl synthetase of tRNA.
- The process begins with the initial phase, which involves binding of the mRNA to ribosomes. This is followed by the transfer and the binding of activated amino acids on the transcriptase.
- The next stage is elongation. the two amino acids get linked by the peptide bond while ribosomes and mRNA move in relation each other to enable the sequential translation of codons.
- When all codons have been translated, the resulting polypeptide sequence is separated with the translation system and ribosomes are released to initiate a new process of translation.
- The termination process is followed by post-translation modifications in which the polypeptide has to be folded in order to get the three-dimensional shape. This happens in the endoplasmic retina and Golgi apparatus in the cell. As a result the polypeptide chains are transported to the organelles.
- Some modifications may be chemical and require the joining functions to the sequence of peptides.
- The process of translation is controlled by the binding of ribosomal subunits with this translation component. Ribosomes are enzymes to regulate different processes.
- In eukaryotes the translation process occurs within the ribosomes of the endoplasmic-reticulum, whereas in prokaryotes it is located within the cytoplasm.
- The translation is blocked by antibiotics, such as tetracycline streptomycin and chloramphenicol anisomycin, cycloheximide and so on.
- Similar to the procedure of translating can also be identified using methods such as western Blotting, immunoblotting enzyme assays, Protein sequencing, etc.
Differences between Transcription and Translation (Transcription vs Translation)
|Base for Comparative||Transcription||Translation|
|Definition||Transcription refers to the process in which the genetic information contained on DNA strands is transferred into an RNA strand through an array of polymerization reactions caused by enzymes called DNA-dependent polymerases.||Translation is the process of protein synthesis, where the information about RNA is expressed as polypeptide chains.|
|Gene expression||Transcription is the very first stage in the expression of genes.||The translation is the 2nd and final stage of gene expression.|
|Occurs||Translation is the process of transcription before transcription.||The transcription process begins after the transcription.|
|Precursor||The transcription precursor is the antisense or non-coding DNA Strand.||The precursor to translation is the mRNA derived by transcription.|
|The raw material||The basic material for transcription includes the four bases pairs in RNA, Adenine, Guanine, Uracil and cytosine.||The amino acids of twenty are the essential ingredients for translation.|
|Initiation||The recognition of certain DNA sequences known as promoter sequences starts transcription and signals the start in the life of the gene.||It is the binding that triggers the translation process into ribosomes.|
|Elongation||The lengthening of RNA sequences happens through the binding of pair of bases onto the newly formed sequence.||The lengthening of proteins occurs through the attachment to amino acids.|
|Product||The result that is produced by transcription mRNA-like molecule, which is a complement to DNA Strand.||The result of translation are the peptide sequences that are encoded from the sequence of mRNA.|
|Synthesis||Transcription leads to the synthesizing of the RNA sequences.||Translation leads to the creation of proteins.|
|Site||The transcription process occurs in the nucleus of Eukaryotes, and in the cells of prokaryotes where the regulators and enzymes are found.||The process of translation occurs in the prokaryotes’ cytoplasm and in the ribosomes of the endoplasmic retina in eukaryotes.|
|Enzymes||The most important enzymes involved in transcription are DNA-dependent polymerase.||The main enzyme the one responsible for transcription is aminoacetyl-tRNA synthetase.|
|Regulation||Transcription is controlled by a variety of transcriptional factors found in eukaryotes, and the operons of prokaryotes.||The control of translation is carried out by interaction of ribosomal units with the transcription complex.|
|Modifications after the event||Post-transcriptional modifications are the modification of the pre-mRNA (the outcome of transcription) through the process of transcription before the mature mRNA is transferred to the ribosomes that are required for translation.||Post-translational modifications involve fold of the polypeptide chain in order to create the three-dimensional structure.|
|Detection||The process is detected using methods such as DNA microarrays, RT-PCR as well as in-situ hybridization and northern Blotting.||Similar to the procedure of translating can also be identified through methods such as western Blotting, immunoblotting enzyme assays, Protein sequencing, etc.|
|Inhibition||It is blocked by certain antibiotics, such as rifampicin or 8-Hydroxy.||The translation is blocked by antibiotics such as tetracycline streptomycin and chloramphenicol anisomycin, Cycloheximide, and so on.|