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: an act, process, or instance of transcribing
2
a : an arrangement of a musical composition for some instrument or voice other than the original
b : a recording (as on magnetic tape) made especially for use in radio broadcasting
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transcriptional tran(t)-ˈskrip-shnəl -shə-nᵊl adjective
Transcription of the tapes took weeks.
Recent Examples on the Web Here's the transcription of that portion of the interview with Hewitt. These example sentences are selected automatically from various online news sources to reflect current usage of the word 'transcription.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
First Known Use 1598, in the meaning defined at sense 1
Time Traveler The first known use of transcription was in 1598See more words from the same year
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“Transcription.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/transcription. Accessed 13 Nov. 2022.
During transcription, the first step of protein synthesis, RNA polymerase converts the genetic information stored in DNA into RNA.
In biology, transcription is the process of transcribing or making a copy of the genetic information stored in a DNA strand into a complementary strand of RNA (messenger RNA or mRNA) with the aid of RNA polymerases. In prokaryotes, the process occurs in the cytoplasm. In eukaryotes, it takes place inside the nucleus. The general steps of transcription are (1) initiation, (2) promoter escape, (3) elongation, and (4) termination. In brief, the RNA polymerase together with certain transcription factors binds to the DNA promoter. This causes the part of the DNA to unwind and form a transcription bubble. A site in the transcription bubble binds to the RNA polymerase. A phase of abortive cycles of short mRNA transcripts are produced and released. The RNA polymerase escapes the promoter to proceed to the elongation step where mRNA transcript is formed while traversing the noncoding strand of the DNA. In the last phase, the hydrogen bonds of the RNA-DNA helix break. In eukaryotes, the mRNA transcript goes through further processing. It goes through polyadenylation, capping, and splicing. After this, the mRNA transcript that carries a copy of the coding segment of the DNA is brought to the ribosomal site for translation. Transcription is a biological process wherein a segment of the DNA is copied to mRNA. The general steps are initiation, promoter escape, elongation, and termination. During initiation, RNA polymerase binds to the promoter region of the DNA. A transcription bubble forms, opening the DNA strand and exposing a segment that will be transcribed. Abortive initiation causes the formation and the release of small RNA products. RNA polymerase, then, escapes the promoter. RNA polymerase adds RNA nucleotides as it traverses the DNA template. RNA sugar-phosphate backbone forms on the RNA strand. Finally, hydrogen bonds of the RNA-DNA helix break in order to release the newly synthesized mRNA transcript. In eukaryotes, post-transcriptional events (e.g. capping, polyadenylation, and splicing) ensue. Transcription is a biological process wherein the mRNA transcript (i.e. a copy of the coding sequence for a particular protein) is produced, generally by transcribing the template strand of the DNA. This transcript serves as a template for the next step of protein biosynthesis, translation, through the help of the enzyme, RNA polymerase. Thus, transcription is regarded as the first step of gene expression and protein biosynthesis. EtymologyThe term transcription came from Latin transcriptiōnem, from trānscrībō, meaning “transcribe”. Central dogmaThe central dogma of molecular biology holds that the genetic information flows from DNA to DNA through the replication and from DNA to mRNA through transcription. mRNA is translated (translation into a protein comprised of a specific sequence of amino acids. The sequence is determined by the sequence of trinucleotide codons. Each codon is a set of three adjacent nucleotides. Transcription vs. replicationBoth transcription and replication are biological processes of producing a copy of DNA. However, the output of replication is an exact copy of DNA whereas in transcription the output is not an exact copy but an mRNA transcript where thymines are replaced by uracils. In replication, the complementary base pairing includes the adenine-thymine (AT) and the guanine-cytosine (GC) base pairings. In transcription, base pairings are adenine-uracil (AU) and guanine-cytosine (GC). In replication, the enzyme involved is DNA polymerase whereas in transcription the enzyme is RNA polymerase. Both replication and transcription proceeds in the 5′ → 3′ direction. But unlike DNA replication, transcription needs no primer to initiate the process. In prokaryotes, both of them occur in the cytoplasm. In eukaryotes, both occur in the nucleus. While replication is a preparatory stage for cell division such as mitosis transcription is the initial stage of gene expression and protein synthesis. Transcription vs. translationBoth transcription and translation are steps in protein biosynthesis. However, transcription occurs first before translation. Transcription produces mRNA that carries the code to be translated into a specific protein (or polypeptide). The code is a copy of the DNA coding segment. It specifies the specific sequence of amino acids. Thus, the flow of genetic information in transcription is from DNA → mRNA whereas in translation the flow is from mRNA → amino acid or protein. Both processes are assisted by enzymes: RNA polymerase assists in transcription whereas ribozyme in translation. In prokaryotes, transcription occurs in the cytoplasm whereas in eukaryotes it occurs in the nucleus. As for translation, it takes place in the cytoplasm where the ribosomes are located in both prokaryotic and eukaryotic cells. Genetic codeRNA codon amino acid chart. In biology, a codon refers to any of a set of three adjacent nucleotides that specify for a particular amino acid. For example, Guanine-Uracil-Uracil (GUU) codes for the amino acid valine. The Cytosine-Uracil-Adenine (CUA) codes for leucine. Uracil-Adenine-Adenine (UAA) is a stop codon. The codons of the mRNA complement the trinucleotides in the tRNA. The trinucleotides in the tRNA are called anticodons. For example, the Guanine-Guanine-Guanine (GGG) codon in the mRNA will complementary pair up with the Cytosine-Cytosine-Cytosine (CCC) anticodon of tRNA. StepsTranscription is the first step of gene expression, in which a particular segment of DNA is copied into RNA by the enzyme RNA polymerase. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes. During transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, antiparallel RNA strand called a primary transcript. As opposed to DNA replication, transcription results in an RNA complement that includes the nucleotide uracil (U) in all instances where thymine (T) would have occurred in a DNA complement. Also unlike DNA replication where DNA is synthesized, transcription does not involve an RNA primer to initiate RNA synthesis. The steps of transcription are as follows: (1) Initiation, (2) Promoter escape, (3) Elongation, and (4) Termination. InitiationRNA polymerase, with the assistance of certain transcription factors, binds to the promoter of DNA, forming RNA polymerase-promoter closed complex. This is then followed by the opening (unwinding) of DNA at the promoter region, forming an open complex. The exposed portion of the DNA following the unwinding forms a transcription bubble. RNA polymerase, then, binds to a transcription start site in the transcription bubble. A phase of abortive initiation (cycles of synthesis) occurs resulting in the release of short mRNA transcripts (about 2 to 15 nucleotides). Promoter escapeThe step after initiation is promoter escape. RNA polymerase escapes the promoter so that it can enter into the elongation step. ElongationAs RNA polymerase traverses the template noncoding strand of the DNA from 3′ → 5′, it facilitates nucleotide base pairing. Nucleotides of the mRNA are added from 5′ → 3′, producing a copy of the non-template coding strand of the DNA, except for the thymine (replaced by uracil). The sugar-phosphate backbone forms through RNA polymerase. Thus, the sugar component of the backbone is a ribose (as opposed to the sugar of DNA, which is a deoxyribose). TerminationDuring this phase, hydrogen bonds of the RNA-DNA helix break. In eukaryotes, the mRNA transcript goes through further processing. It goes through polyadenylation, capping, and splicing. The termination mechanism employed by prokaryotes may either be rho-dependent or rho-independent. In eukaryotes, termination involves both the poly A signal and the downstream terminator sequence. Prokaryotic transcription vs. eukaryotic transcriptionIn both prokaryotes and eukaryotes, the genetic flow in transcription is from DNA to RNA. Both use RNA polymerase to assist in the process. However, eukaryotes have three types of RNA polymerases (I, II, and III). Prokaryotes have only one type. Related terms
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