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MRNA
In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of Protein biosynthesis, synthesizing a protein. mRNA is created during the process of Transcription (biology), transcription, where an enzyme (RNA polymerase) converts the gene into primary transcript mRNA (also known as pre-mRNA). This pre-mRNA usually still contains introns, regions that will not go on to code for the final amino acid sequence. These are removed in the process of RNA splicing, leaving only exons, regions that will encode the protein. This exon sequence constitutes mature mRNA. Mature mRNA is then read by the ribosome, and the ribosome creates the protein utilizing amino acids carried by transfer RNA (tRNA). This process is known as Translation (biology), translation. All of these processes form part of the central dogma of molecular biology, which describes the flow of geneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Biosynthesis
Protein biosynthesis, or protein synthesis, is a core biological process, occurring inside Cell (biology), cells, homeostasis, balancing the loss of cellular proteins (via Proteolysis, degradation or Protein targeting, export) through the production of new proteins. Proteins perform a number of critical functions as enzymes, structural proteins or hormones. Protein synthesis is a very similar process for both prokaryotes and eukaryotes but there are some distinct differences. Protein synthesis can be divided broadly into two phases: Transcription (biology), transcription and Translation (biology), translation. During transcription, a section of DNA encoding a protein, known as a gene, is converted into a molecule called messenger RNA (mRNA). This conversion is carried out by enzymes, known as RNA polymerases, in the cell nucleus, nucleus of the cell. In eukaryotes, this mRNA is initially produced in a premature form (Primary transcript, pre-mRNA) which undergoes post-transcriptio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary Transcript
A primary transcript is the single-stranded ribonucleic acid (RNA) product synthesized by transcription of DNA, and processed to yield various mature RNA products such as mRNAs, tRNAs, and rRNAs. The primary transcripts designated to be mRNAs are modified in preparation for translation. For example, a precursor mRNA (pre-mRNA) is a type of primary transcript that becomes a messenger RNA (mRNA) after processing. Pre-mRNA is synthesized from a DNA template in the cell nucleus by transcription. Pre-mRNA comprises the bulk of heterogeneous nuclear RNA (hnRNA). Once pre-mRNA has been completely processed, it is termed " mature messenger RNA", or simply "messenger RNA". The term hnRNA is often used as a synonym for pre-mRNA, although, in the strict sense, hnRNA may include nuclear RNA transcripts that do not end up as cytoplasmic mRNA. There are several steps contributing to the production of primary transcripts. All these steps involve a series of interactions to initiate and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pre-mRNA
A primary transcript is the single-stranded ribonucleic acid (RNA) product synthesized by Transcription (genetics), transcription of DNA, and processed to yield various mature RNA products such as mRNAs, tRNAs, and rRNAs. The primary transcripts designated to be mRNAs are modified in preparation for Translation (biology), translation. For example, a precursor mRNA (pre-mRNA) is a type of primary transcript that becomes a messenger RNA (mRNA) after Post-transcriptional modification, processing. Pre-mRNA is synthesized from a DNA template in the cell nucleus by transcription (genetics), transcription. Pre-mRNA comprises the bulk of heterogeneous nuclear RNA (hnRNA). Once pre-mRNA has been completely Post-transcriptional modification, processed, it is termed "mature messenger RNA", or simply "messenger RNA". The term hnRNA is often used as a synonym for pre-mRNA, although, in the strict sense, hnRNA may include nuclear RNA transcripts that do not end up as cytoplasmic mRNA. There ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Translation (biology)
In biology, translation is the process in living Cell (biology), cells in which proteins are produced using RNA molecules as templates. The generated protein is a sequence of amino acids. This sequence is determined by the sequence of nucleotides in the RNA. The nucleotides are considered three at a time. Each such triple results in the addition of one specific amino acid to the protein being generated. The matching from nucleotide triple to amino acid is called the genetic code. The translation is performed by a large complex of functional RNA and proteins called ribosomes. The entire process is called gene expression. In translation, messenger RNA (mRNA) is decoded in a ribosome, outside the nucleus, to produce a specific amino acid chain, or polypeptide. The polypeptide later protein folding, folds into an Activation energy, active protein and performs its functions in the cell. The polypeptide can also start folding during protein synthesis. The ribosome facilitates decoding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNA Splicing
RNA splicing is a process in molecular biology where a newly-made precursor messenger RNA (pre-mRNA) transcription (biology), transcript is transformed into a mature messenger RNA (Messenger RNA, mRNA). It works by removing all the introns (non-coding regions of RNA) and ''splicing'' back together exons (coding regions). For nuclear genes, nuclear-encoded genes, splicing occurs in the cell nucleus, nucleus either during or immediately after Transcription (biology), transcription. For those eukaryotic transcription, eukaryotic genes that contain introns, splicing is usually needed to create an mRNA molecule that can be translation (biology), translated into protein. For many eukaryotic introns, splicing occurs in a series of reactions which are catalyzed by the spliceosome, a complex of small nuclear ribonucleoproteins (snRNPs). There exist self-splicing introns, that is, ribozymes that can catalyze their own excision from their parent RNA molecule. The process of transcription, spli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribosome
Ribosomes () are molecular machine, macromolecular machines, found within all cell (biology), cells, that perform Translation (biology), biological protein synthesis (messenger RNA translation). Ribosomes link amino acids together in the order specified by the codons of messenger RNA molecules to form polypeptide chains. Ribosomes consist of two major components: the small and large ribosomal subunits. Each subunit consists of one or more ribosomal RNA molecules and many ribosomal proteins (). The ribosomes and associated molecules are also known as the ''translational apparatus''. Overview The sequence of DNA that encodes the sequence of the amino acids in a protein is transcribed into a messenger RNA (mRNA) chain. Ribosomes bind to the messenger RNA molecules and use the RNA's sequence of nucleotides to determine the sequence of amino acids needed to generate a protein. Amino acids are selected and carried to the ribosome by transfer RNA (tRNA) molecules, which enter the riboso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and non-coding genes. During gene expression (the synthesis of Gene product, RNA or protein from a gene), DNA is first transcription (biology), copied into RNA. RNA can be non-coding RNA, directly functional or be the intermediate protein biosynthesis, template for the synthesis of a protein. The transmission of genes to an organism's offspring, is the basis of the inheritance of phenotypic traits from one generation to the next. These genes make up different DNA sequences, together called a genotype, that is specific to every given individual, within the gene pool of the population (biology), population of a given species. The genotype, along with environmental and developmental factors, ultimately determines the phenotype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Introns
An intron is any Nucleic acid sequence, nucleotide sequence within a gene that is not expressed or operative in the final RNA product. The word ''intron'' is derived from the term ''intragenic region'', i.e., a region inside a gene."The notion of the cistron [i.e., gene] ... must be replaced by that of a transcription unit containing regions which will be lost from the mature messenger – which I suggest we call introns (for intragenic regions) – alternating with regions which will be expressed – exons." (Gilbert 1978) The term ''intron'' refers to both the DNA sequence within a gene and the corresponding RNA sequence in RNA Transcription (genetics), transcripts. The non-intron sequences that become joined by this RNA processing to form the mature RNA are called exons. Introns are found in the genes of most eukaryotes and many eukaryotic viruses, and they can be located in both protein-coding genes and genes that function as RNA (Non-coding RNA, noncoding genes). There are f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transfer RNA
Transfer ribonucleic acid (tRNA), formerly referred to as soluble ribonucleic acid (sRNA), is an adaptor molecule composed of RNA, typically 76 to 90 nucleotides in length (in eukaryotes). In a cell, it provides the physical link between the genetic code in messenger RNA (mRNA) and the amino acid sequence of proteins, carrying the correct sequence of amino acids to be combined by the protein-synthesizing machinery, the ribosome. Each three-nucleotide codon in mRNA is complemented by a three-nucleotide anticodon in tRNA. As such, tRNAs are a necessary component of translation, the biological synthesis of new proteins in accordance with the genetic code. Overview The process of translation starts with the information stored in the nucleotide sequence of DNA. This is first transformed into mRNA, then tRNA specifies which three-nucleotide codon from the genetic code corresponds to which amino acid. Each mRNA codon is recognized by a particular type of tRNA, which docks to it along ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mature MRNA
Mature messenger RNA, often abbreviated as mature mRNA is a eukaryotic RNA transcript that has been spliced and processed and is ready for translation in the course of protein synthesis. Unlike the eukaryotic RNA immediately after transcription known as precursor messenger RNA, mature mRNA consists exclusively of exons and has all introns removed. Mature mRNA is also called "mature transcript", "mature RNA" or "mRNA". The production of a mature mRNA molecule occurs in 3 steps: # Capping of the 5' end # Polyadenylation of the 3' end # RNA Splicing of the introns Capping the 5' End During capping, a 7-methylguanosine residue is attached to the 5'-terminal end of the primary transcripts.This is otherwise known as the GTP or 5' cap. The 5' cap is used to increase mRNA stability. Further, the 5' cap is used as an attachment point for ribosomes. Beyond this, the 5' cap has also been shown to have a role in exporting the mature mRNA from the nucleus and into the cytoplasm. P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribosomal RNA
Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosomal DNA (rDNA) and then bound to ribosomal proteins to form SSU rRNA, small and LSU rRNA, large ribosome subunits. rRNA is the physical and mechanical factor of the ribosome that forces transfer RNA (tRNA) and messenger RNA (mRNA) to process and Translation (biology), translate the latter into proteins. Ribosomal RNA is the predominant form of RNA found in most cells; it makes up about 80% of cellular RNA despite never being translated into proteins itself. Ribosomes are composed of approximately 60% rRNA and 40% ribosomal proteins, though this ratio differs between Prokaryote, prokaryotes and Eukaryote, eukaryotes. Structure Although the primary structure of rRNA sequences can vary across organisms, Base pair, base-pairing within these sequ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exons
An exon is any part of a gene that will form a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing. The term ''exon'' refers to both the DNA sequence within a gene and to the corresponding sequence in RNA transcripts. In RNA splicing, introns are removed and exons are covalently joined to one another as part of generating the mature RNA. Just as the entire set of genes for a species constitutes the genome, the entire set of exons constitutes the exome. History The term ''exon'' is a shortening of the phrase ''expressed region'' and was coined by American biochemist Walter Gilbert in 1978: "The notion of the cistron... must be replaced by that of a transcription unit containing regions which will be lost from the mature messengerwhich I suggest we call introns (for intragenic regions)alternating with regions which will be expressedexons." This definition was originally made for protein-coding transcripts that are spliced before bei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
