A polymeric constituent of all living cells and many viruses, consisting of a long, usually single-stranded chain of alternating phosphate and ribose units with the bases adenine, guanine, cytosine, and uracil bonded to the ribose. The structure and base sequence of RNA are determinants of protein synthesis and the transmission of genetic information. Also called ribonucleic acid.
RNA
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RNA (är'ĕn-ā')  |
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| Genetics Encyclopedia: RNA |
Ribonucleic acid (RNA) molecules, which are linear chains (or polymers) of ribonucleotides, perform a number of critical functions. Many of these functions are related to protein synthesis. Some RNA molecules bring genetic information from a cell's chromosomes to its ribosomes, where proteins are assembled. Others help ribosomes translate genetic information to assemble specific sequences of amino acids.
Molecular Structure
Ribonucleotides, the building blocks of RNA, are molecules that consist of a nitrogen-containing base, a phosphate group, and ribose, a five-carbon sugar. The nitrogen-containing base may be adenine, cytosine, guanine, or uracil. These four bases are abbreviated as A, C, G, and U.
RNA is similar to deoxyribonucleic acid (DNA), another class of nucleic acid. However, DNA nucleotides contain deoxyribose, not ribose, and they use the nitrogen-containing base thymine (T), not uracil, along with ade-nine, cytosine, and guanine.
The nucleotides in DNA and RNA molecules are linked together to form chains. The link between two nucleotides is between a phosphate group attached to the fifth (5′ or "five prime") carbon of the sugar on one nucleotide and a hydroxyl group on the third (3′ or "three prime") carbon of the sugar on the other. The link is called a 5′-3′ phosphodiester bond.
RNA, therefore, can be described as a chain of ribose sugars linked together by phosphodiester bonds, with a base protruding from each sugar, as shown in the figure below. The 5′-3′ linkage gives RNA directionality, or polarity, and results in its having two ends with different chemical structures. The 5′ end usually has one or three free phosphate groups, and the 3′ end usually has a free hydroxyl group.
Whereas DNA is usually double-stranded, with the bases on one strand pairing up with those on the other, RNA usually exists as single chains of nucleotides. The bases in RNA do, however, follow Watson-Crick base-pair rules: A and U can pair with each other, as can G and C. There is usually extensive pairing of bases within a single strand of RNA.
RNA strands fold, with the bases in one part of the strand pairing with the bases in another. Folding can create both "secondary" and "tertiary" structures. Secondary structures are those that can be described in two dimensions and that can be thought of as simple loops or helices. Tertiary structures are complex, three-dimensional shapes.
The most common secondary structures, "hairpins," "loops," and "pseudo-knots," are shown in the figure below. Such secondary structures are formed when hydrogen bonds form between bases in the nucleotides and by the stacking of bases to form helical structures.
Tertiary structures usually involve interactions between nucleotides that are distant from each other along an RNA strand. Such interactions may arise from hydrogen bonding between bases, as in regular Watson-Crick base pairing, or from interactions among other chemical groups in the nucleotides. Some RNA molecules, such as ribosomal RNA (rRNA) and transfer RNA (tRNA), have structures that are very complex. In structure they resemble proteins more than they do DNA.
To understand the function of a given RNA molecule, scientists often need to know its structure. There are three general strategies for analyzing RNA structure. First, using the relatively simple base-pairing rules for RNA and the basic principles of thermodynamics, computers can be used to predict secondary RNA structure, although not always with complete success.
Second, researchers can analyze RNA molecules from various organisms and compare those molecules that have the same function. Even when the nucleotide sequences vary between species, important structures are usually preserved.
Third, the structure of an RNA molecule can be determined experimentally, using enzymes to cut it or chemicals to modify it. Some enzymes and chemicals cut or modify only nonpaired, single-stranded portions of the RNA molecule, allowing researchers to identify double-stranded regions by examining which ones remain uncut and unmodified.
Despite the usefulness of each of these methods, none can provide a complete and accurate three-dimensional structure. A more complete determination of structure can be achieved by the biophysical methods of X-ray crystallography and nuclear magnetic resonance.
Synthesis
RNA molecules are synthesized by enzymes known as RNA polymerases in a process called transcription. Usually, one strand of a double-stranded DNA molecule is used as a template for the RNA. The order of ribonucleotides that are assembled to form the RNA molecule is determined by the order of the deoxyribonucleotides in the DNA strand. The genetic information in the DNA sequence is thus reproduced in the RNA molecule. Sometimes, but rarely, an RNA molecule is synthesized using another RNA molecule as the template.
Often, when RNA molecules are synthesized, they are in a form that prevents them from carrying out their function. To become functional, they must undergo processing, which can involve removing segments of the strands or modifying specific nucleotides. The link between a base and a ribose may be altered, or extra chemical groups may be added to the bases or ribose molecules. Many RNA molecules are associated with proteins during or after their synthesis. Together, the RNA and protein are referred to as RNA-protein particles (RNPs).
In eukaryotes, RNA that is encoded by nuclear chromosomes is synthesized in the nucleus. The processing and assembly of many small RNA molecules in higher eukaryotes is accomplished in Cajal bodies, which are coiled structures in the nucleus that were identified more than 100 years ago but that have begun to be investigated in detail only recently. The synthesis of those RNA molecules that are components of ribosomes occurs in the nucleolus, a part of the nucleus. RNA synthesis and processing also occurs in the mitochondria and chloroplasts, when the RNA will be used in those organelles.
After being processed and assembled, RNPs either remain in the nucleus or are exported to the cytoplasm through the nuclear pores. Some are also exported and modified in the cytoplasm and then imported back into the nucleus. In prokaryotes, where there is no nucleus, the synthesis and processing of RNA, as well as the assembly of RNPs, occurs in the cytoplasm.
Function
Almost all types of RNA play a role in translation, which is the process of protein synthesis. Translation requires three types of RNA: messenger RNA (mRNA), which ranges in length from a few hundred to many thousands of nucleotides; tRNA, which is 75 to 85 nucleotides long; and rRNA, which is 1,500 to 4,000 nucleotides long.
Molecules of mRNA, each of which contains a copy of at least one gene, are the intermediates between DNA and protein. These mRNA molecules bring the genetic code from the DNA, which is in the nucleus, to ribosomes, which are in the cytoplasm. They attach to the ribosomes and determine the order in which amino acids are assembled to synthesize a protein. Of the three types of RNA required for translation, mRNA molecules have the simplest structure.
Next, tRNA molecules function as adapters that help translate the nucleotide sequences in mRNA into amino acid sequences, so specific proteins can be constructed. There are many different types of tRNA, each of which is capable of binding to one of the twenty amino acids that are the building blocks of proteins.
Finally, rRNA molecules, which account for most of a ribosome's mass, are, according to recent experiments, the part of the ribosome responsible for linking amino acids into a growing protein chain. Ribosomes, the organelles that assemble a particular sequence of amino acids to form proteins, contain three or four different molecules of rRNA, along with at least fifty different proteins.
Both rRNA and tRNA are stable forms of RNA that last through several cell divisions. In contrast, mRNA is normally unstable, with a lifetime that can be as short as a few minutes. This instability has probably evolved because it lets cells quickly stop synthesizing proteins that are no longer needed. In some cases, enzymes called ribonucleases (RNases) actively degrade certain mRNA molecules. For example, mRNA that encodes a particular protein regulating the cell cycle is degraded when the protein has carried out its function.
In certain cells, mRNA can exist in a stable form for decades. When egg cells are formed, for example, some of the mRNA in the cells is associated with "storage proteins" and lasts until after the eggs are fertilized. During embryonic development, this maternal mRNA becomes activated for translation and associates with translating ribosomes. It usually decays after it has been used to produce a certain amount of protein.
Less Common Types of Rna
Several types of less abundant, small RNA molecules perform essential functions in both the nucleus and the cytoplasm. All organisms contain cytoplasmic RNPs that are involved in exporting proteins from cells. During the synthesis of proteins that are destined to be exported, the ribosome and mRNA associate with an "export-RNP," which helps them dock at an export pore in the cell membrane. As it formed, the protein is threaded through the membrane to the outside of the cell. In eukaryotes, this same strategy is used to transport proteins into the endoplasmic reticulum, where some newly synthesized proteins are sorted and modified.
RNase P is another RNP found in all forms of life. This RNA-containing enzyme helps turn precursor tRNA into mature tRNA molecules. It does so by cleaving a section off the 5′ end of the precursor molecules.
Small nucleolar RNAs, which are known as snoRNAs and which are found in the nucleoli of eukaryotes and in Archaea, are required for the processing of precursor rRNA. During the assembly of new ribosomes, snoRNAs help remove regions of the precursor molecules and modify specific nucleotides.
Often, mRNA molecules in eukaryotes and in Archaea contain sequences that do not code for amino acids. These sequences, called introns, must be spliced out before translation begins. In eukaryotes, small nuclear RNAs (snRNAs) in the nucleus remove these introns. Once the introns are removed, the mature mRNA molecules are exported, through nuclear pores, into the cytoplasm, where they associate with ribosomes for translation.
Some viral genomes consist of single-stranded or double-stranded RNA, not DNA. Examples are found among both prokaryotic and eukaryotic viruses and include HIV, as well as viruses causing some forms of cancer.
Bibliography
Lodish, Harvey, et al. Molecular Cell Biology, 4th ed. New York: W. H. Freeman, 2000.
Meili, M., B. Albert-Fournier, and M. C. Maurel. "Recent Findings in the Modern RNA World." International Microbiology 4 (2001): 5-11.
Robinson, Richard. Biology. Farmington Hills, MI: Macmillan Reference USA, 2002.
Storz, G. "An Expanding Universe of Non-coding RNAs." Science 296 (2002): 1260-1263.
—Lasse Lindahl
| Britannica Concise Encyclopedia: RNA |
For more information on RNA, visit Britannica.com.
| Science Dictionary: RNA |
One of a group of molecules similar in structure to a single strand of DNA. The function of RNA is to carry the information from DNA in the cell's nucleus into the body of the cell, to use the genetic code to assemble proteins, and to comprise part of the ribosomes that serve as the platform on which protein synthesis takes place.
| Veterinary Dictionary: RNA |
Ribonucleic acid.
- RNA interference (RNAi) — the functional inactivation of specific genes by experimental introduction of a corresponding double stranded RNA, which induces degradation of the complementary single-stranded mRNA encoded by the gene but not that of mRNAs with different sequences. See
microRNA and gene silencing. - microRNA (miRNA) — small RNAs containing 21 to 33 nucleotides that associated with multiple proteins in a RNA-induced silencing complex (RISC) that repress transcription of specific target mRNA by hybridizing to its 3’ untranslated region.
- RNA primer — a sequence of about 10 nucleotides long copied from DNA by RNA primase and required for the priming of the synthesis of each Okazaki fragment during DNA replication.
- secondary structure RNA — folding of single-stranded RNA molecules which arises from intramolecular base pairing.
- small cytoplasmic RNA (scRNA) — small (7S; 129 nucleotides) RNA molecules found in the cytosol and rough endoplasmic reticulum associated with proteins that are involved in specific selection and transport of other proteins.
- small nuclear RNA (snRNA) — a general term for many diferent kinds of small RNA molecules found in the nucleus of a cell that include as examples species involved in splicing of introns from mRNA and in RNA interference.
- RNA viruses — viruses distinguished by having a ribonucleic acid genome, usually as a single strand which may be positive or negative sense, a single molecule or a segmented; in at least two families the genome is a double-strand segmented form.
| Wikipedia: RNA |
For other uses, see RNA (disambiguation).
Ribonucleic acid (RNA) is a biologically important type of molecule that consists of a long chain of nucleotide units. Each nucleotide consists of a nitrogenous base, a ribose sugar, and a phosphate. RNA is very similar to DNA, but differs in a few important structural details: in the cell, RNA is usually single-stranded, while DNA is usually double-stranded; RNA nucleotides contain ribose while DNA contains deoxyribose (a type of ribose that lacks one oxygen atom); and RNA has the base uracil rather than thymine that is present in DNA.
RNA is transcribed from DNA by enzymes called RNA polymerases and is generally further processed by other enzymes. RNA is central to the synthesis of proteins. Here, a type of RNA called messenger RNA carries information from DNA to structures called ribosomes. These ribosomes are made from proteins and ribosomal RNAs, which come together to form a molecular machine that can read messenger RNAs and translate the information they carry into proteins. There are many RNAs with other roles – in particular regulating which genes are expressed, but also as the genomes of most viruses.
Contents |
Structure
Each nucleotide in RNA contains a ribose sugar, with carbons numbered 1' through 5'. A base is attached to the 1' position, generally adenine (A), cytosine (C), guanine (G) or uracil (U). Adenine and guanine are purines, cytosine and uracil are pyrimidines. A phosphate group is attached to the 3' position of one ribose and the 5' position of the next. The phosphate groups have a negative charge each at physiological pH, making RNA a charged molecule (polyanion). The bases may form hydrogen bonds between cytosine and guanine, between adenine and uracil and between guanine and uracil.[1] However other interactions are possible, such as a group of adenine bases binding to each other in a bulge,[2] or the GNRA tetraloop that has a guanine–adenine base-pair.[1]
An important structural feature of RNA that distinguishes it from DNA is the presence of a hydroxyl group at the 2' position of the ribose sugar. The presence of this functional group causes the helix to adopt the A-form geometry rather than the B-form most commonly observed in DNA.[3] This results in a very deep and narrow major groove and a shallow and wide minor groove.[4] A second consequence of the presence of the 2'-hydroxyl group is that in conformationally flexible regions of an RNA molecule (that is, not involved in formation of a double helix), it can chemically attack the adjacent phosphodiester bond to cleave the backbone.[5]
RNA is transcribed with only four bases (adenine, cytosine, guanine and uracil),[6] but there are numerous modified bases and sugars in mature RNAs. Pseudouridine (Ψ), in which the linkage between uracil and ribose is changed from a C–N bond to a C–C bond, and ribothymidine (T), are found in various places (most notably in the TΨC loop of tRNA).[7] Another notable modified base is hypoxanthine, a deaminated adenine base whose nucleoside is called inosine (I). Inosine plays a key role in the wobble hypothesis of the genetic code.[8] There are nearly 100 other naturally occurring modified nucleosides,[9] of which pseudouridine and nucleosides with 2'-O-methylribose are the most common.[10] The specific roles of many of these modifications in RNA are not fully understood. However, it is notable that in ribosomal RNA, many of the post-transcriptional modifications occur in highly functional regions, such as the peptidyl transferase center and the subunit interface, implying that they are important for normal function.[11]
The functional form of single stranded RNA molecules, just like proteins, frequently requires a specific tertiary structure. The scaffold for this structure is provided by secondary structural elements which are hydrogen bonds within the molecule. This leads to several recognizable "domains" of secondary structure like hairpin loops, bulges and internal loops.[12] Since RNA is charged, metal ions such as Mg2+ are needed to stabilise many secondary structures.[13]
Comparison with DNA
RNA and DNA are both nucleic acids, but differ in three main ways. First, unlike DNA which is double-stranded, RNA is a single-stranded molecule in most of its biological roles and has a much shorter chain of nucleotides. Second, while DNA contains deoxyribose, RNA contains ribose, (there is no hydroxyl group attached to the pentose ring in the 2' position in DNA). These hydroxyl groups make RNA less stable than DNA because it is more prone to hydrolysis. Third, the complementary base to adenine is not thymine, as it is in DNA, but rather uracil, which is an unmethylated form of thymine.[14]
Like DNA, most biologically active RNAs, including mRNA, tRNA, rRNA, snRNAs and other non-coding RNAs, contain self-complementary sequences that allow parts of the RNA to fold and pair with itself to form double helices. Structural analysis of these RNAs have revealed that they are highly structured. Unlike DNA, their structures do not consist of long double helices but rather collections of short helices packed together into structures akin to proteins. In this fashion, RNAs can achieve chemical catalysis, like enzymes.[15] For instance, determination of the structure of the ribosome—an enzyme that catalyzes peptide bond formation—revealed that its active site is composed entirely of RNA.[16]
Synthesis
Synthesis of RNA is usually catalyzed by an enzyme—RNA polymerase—using DNA as a template, a process known as transcription. Initiation of transcription begins with the binding of the enzyme to a promoter sequence in the DNA (usually found "upstream" of a gene). The DNA double helix is unwound by the helicase activity of the enzyme. The enzyme then progresses along the template strand in the 3’ to 5’ direction, synthesizing a complementary RNA molecule with elongation occurring in the 5’ to 3’ direction. The DNA sequence also dictates where termination of RNA synthesis will occur.[17]
RNAs are often modified by enzymes after transcription. For example, a poly(A) tail and a 5' cap are added to eukaryotic pre-mRNA and introns are removed by the spliceosome.
There are also a number of RNA-dependent RNA polymerases that use RNA as their template for synthesis of a new strand of RNA. For instance, a number of RNA viruses (such as poliovirus) use this type of enzyme to replicate their genetic material.[18] Also, RNA-dependent RNA polymerase is part of the RNA interference pathway in many organisms.[19]
Types of RNA
See also: List of RNAs
Overview
Messenger RNA (mRNA) is the RNA that carries information from DNA to the ribosome, the sites of protein synthesis (translation) in the cell. The coding sequence of the mRNA determines the amino acid sequence in the protein that is produced.[20] Many RNAs do not code for protein however (about 97% of the transcriptial output is non-protein-coding in eukaryotes [21][22][23][24]).
These so-called non-coding RNAs ("ncRNA") can be encoded by their own genes (RNA genes), but can also derive from mRNA introns.[25] The most prominent examples of non-coding RNAs are transfer RNA (tRNA) and ribosomal RNA (rRNA), both of which are involved in the process of translation.[14] There are also non-coding RNAs involved in gene regulation, RNA processing and other roles, possibly including a postulated role as the physical embodiment of Piaget's abstract "schèmes" which he saw as underlying repeatable action patterns and advanced thought-and-memory.[26] Certain RNAs are able to catalyse chemical reactions such as cutting and ligating other RNA molecules,[27] and the catalysis of peptide bond formation in the ribosome;[16] these are known as ribozymes.
In translation
Messenger RNA (mRNA) carries information about a protein sequence to the ribosomes, the protein synthesis factories in the cell. It is coded so that every three nucleotides (a codon) correspond to one amino acid. In eukaryotic cells, once precursor mRNA (pre-mRNA) has been transcribed from DNA, it is processed to mature mRNA. This removes its introns—non-coding sections of the pre-mRNA. The mRNA is then exported from the nucleus to the cytoplasm, where it is bound to ribosomes and translated into its corresponding protein form with the help of tRNA. In prokaryotic cells, which do not have nucleus and cytoplasm compartments, mRNA can bind to ribosomes while it is being transcribed from DNA. After a certain amount of time the message degrades into its component nucleotides with the assistance of ribonucleases.[20]
Transfer RNA (tRNA) is a small RNA chain of about 80 nucleotides that transfers a specific amino acid to a growing polypeptide chain at the ribosomal site of protein synthesis during translation. It has sites for amino acid attachment and an anticodon region for codon recognition that binds to a specific sequence on the messenger RNA chain through hydrogen bonding.[25]
Ribosomal RNA (rRNA) is the catalytic component of the ribosomes. Eukaryotic ribosomes contain four different rRNA molecules: 18S, 5.8S, 28S and 5S rRNA. Three of the rRNA molecules are synthesized in the nucleolus, and one is synthesized elsewhere. In the cytoplasm, ribosomal RNA and protein combine to form a nucleoprotein called a ribosome. The ribosome binds mRNA and carries out protein synthesis. Several ribosomes may be attached to a single mRNA at any time.[20] rRNA is extremely abundant and makes up 80% of the 10 mg/ml RNA found in a typical eukaryotic cytoplasm.[28]
Transfer-messenger RNA (tmRNA) is found in many bacteria and plastids. It tags proteins encoded by mRNAs that lack stop codons for degradation and prevents the ribosome from stalling.[29]
Regulatory RNAs
Several types of RNA can downregulate gene expression by being complementary to a part of an mRNA or a gene's DNA. MicroRNAs (miRNA; 21-22 nt) are found in eukaryotes and act through RNA interference (RNAi), where an effector complex of miRNA and enzymes can break down mRNA which the miRNA is complementary to, block the mRNA from being translated, or accelerate its degradation.[30][31] While small interfering RNAs (siRNA; 20-25 nt) are often produced by breakdown of viral RNA, there are also endogenous sources of siRNAs.[32][33] siRNAs act through RNA interference in a fashion similar to miRNAs. Some miRNAs and siRNAs can cause genes they target to be methylated, thereby decreasing or increasing transcription of those genes.[34][35][36] Animals have Piwi-interacting RNAs (piRNA; 29-30 nt) which are active in germline cells and are thought to be a defense against transposons and play a role in gametogenesis.[37][38] All prokaryotes have CRISPR RNAs, a regulatory system analogous to RNA interference.[39] Antisense RNAs are widespread; most downregulate a gene, but a few are activators of transcription.[40] One way antisense RNA can act is by binding to an mRNA, forming double-stranded RNA that is enzymatically degraded.[41] There are many long noncoding RNAs that regulate genes in eukaryotes,[42] one such RNA is Xist which coats one X chromosome in female mammals and inactivates it.[43]
An mRNA may contain regulatory elements itself, such as riboswitches, in the 5' untranslated region or 3' untranslated region; these cis-regulatory elements regulate the activity of that mRNA.[44] The untranslated regions can also contain elements that regulate other genes.[45]
In RNA processing
Many RNAs are involved in modifying other RNAs. Introns are spliced out of pre-mRNA by spliceosomes, which contain several small nuclear RNAs (snRNA),[14] or the introns can be ribozymes that are spliced by themselves.[46] RNA can also be altered by having its nucleotides modified to other nucleotides than A, C, G and U. In eukaryotes, modifications of RNA nucleotides are generally directed by small nucleolar RNAs (snoRNA; 60-300 nt),[25] found in the nucleolus and cajal bodies. snoRNAs associate with enzymes and guide them to a spot on an RNA by basepairing to that RNA. These enzymes then perform the nucleotide modification. rRNAs and tRNAs are extensively modified, but snRNAs and mRNAs can also be the target of base modification.[47][48]
RNA genomes
Like DNA, RNA can carry genetic information. RNA viruses have genomes composed of RNA, and a variety of proteins encoded by that genome. The viral genome is replicated by some of those proteins, while other proteins protect the genome as the virus particle moves to a new host cell. Viroids are another group of pathogens, but they consist only of RNA, do not encode any protein and are replicated by a host plant cell's polymerase.[49]
In reverse transcription
Reverse transcribing viruses replicate their genomes by reverse transcribing DNA copies from their RNA; these DNA copies are then transcribed to new RNA. Retrotransposons also spread by copying DNA and RNA from one another,[50] and telomerase contains an RNA that is used as template for building the ends of eukaryotic chromosomes.[51]
Double-stranded RNA
Double-stranded RNA (dsRNA) is RNA with two complementary strands, similar to the DNA found in all cells. dsRNA forms the genetic material of some viruses (double-stranded RNA viruses). Double-stranded RNA such as viral RNA or siRNA can trigger RNA interference in eukaryotes, as well as interferon response in vertebrates.[52][53][54]
Discovery
Nucleic acids were discovered in 1868 by Friedrich Miescher, who called the material 'nuclein' since it was found in the nucleus.[55] It was later discovered that prokaryotic cells, which do not have a nucleus, also contain nucleic acids. The role of RNA in protein synthesis was suspected already in 1939.[56] Severo Ochoa won the 1959 Nobel Prize in Medicine after he discovered how RNA is synthesized.[57] The sequence of the 77 nucleotides of a yeast tRNA was found by Robert W. Holley in 1965,[58] winning Holley the 1968 Nobel Prize in Medicine. In 1967, Carl Woese realized RNA can be catalytic and proposed that the earliest forms of life relied on RNA both to carry genetic information and to catalyze biochemical reactions—an RNA world.[59][60] In 1976, Walter Fiers and his team determined the first complete nucleotide sequence of an RNA virus genome, that of bacteriophage MS2.[61] In 1990 it was found in petunia that introduced genes can silence similar genes of the plant's own, now known to be a result of RNA interference.[62][63] At about the same time, 22 nt long RNAs, now called microRNAs, were found to have a role in the development of C. elegans.[64] The discovery of gene regulatory RNAs has led to attempts to develop drugs made of RNA, such as siRNA, to silence genes.[65]
See also
- Genetics
- Molecular biology
- Oligonucleotide synthesis
- Quantification of nucleic acids
- RNA Ontology Consortium
- Sequence profiling tool
- RNA extraction
- RNA structure prediction
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External links
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Wikimedia Commons has media related to: RNA |
- RNA World website Link collection (structures, sequences, tools, journals)
- Nucleic Acid Database Images of DNA, RNA and complexes.
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| Translations: Rna |
Dansk (Danish)
n. - RNA (ribonukleinsyre)
Nederlands (Dutch)
RNA, ribonucleïnezuur
Français (French)
n. - (Biol) acide ribonucléique
Ελληνική (Greek)
abbr. - ριβο(ζο)νουκλεϊνικό οξύ
Italiano (Italian)
acido ribonucleico
Português (Portuguese)
abbr. - ácido ribonucléico
Русский (Russian)
РНК-рибонуклеиновая кислота
Español (Spanish)
n. - ARN - ácido ribonucleico
Svenska (Swedish)
abbr. - (kem) ribunokleinsyra
中文（简体）(Chinese (Simplified))
核糖核酸
中文（繁體）(Chinese (Traditional))
n. - 核糖核酸
العربيه (Arabic)
(اختصار) حامض يعيش في كروموسومات الأشياء الحيه
עברית (Hebrew)
n. - רנ"א (חומצה ריבונוקלאית)
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| Nucleotide |
| Ribosome |
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Related answers
- What rna enzyme breaks down the dna molecule to form messenger rna?
- What must happen to a dna molecule before rna ploymerase can make rna?
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Answer these
- What must happen to a rna mollecule before rna polymerase can make rna?
- Which enzyme links RNA nucleotides together to form an RNA molecule?
Mentioned in
- antisense RNA
- RNA virus (RNA-containing virus)
- spliceosome
- mRNA (abbreviation)
- rRNA (abbreviation)
- tRNA (abbreviation)
- sRNA (abbreviation)
- hnRNA
- scRNA
- ribonuclease
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