RNA - Revision history

JoeyJ at 17:32, February 11, 2017

2017-02-11T17:32:58Z

DavidB4-bot: clean up

2016-06-23T12:54:33Z

clean up

JHunter at 18:53, May 4, 2013

2013-05-04T18:53:19Z

JHunter: categories

2012-12-08T04:32:27Z

JHunter at 00:41, November 7, 2012

2012-11-07T00:41:32Z

JHunter: /* Function */ snurps

2012-11-07T00:38:14Z

Function: snurps

JHunter: /* Function */ microRNAs and siRNAs, will expand more later

2012-11-06T21:07:26Z

Function: microRNAs and siRNAs, will expand more later

JHunter: saving progress again

2012-11-04T04:30:38Z

saving progress again

JHunter: my internet connection is kind of spotty, so I'm saving again

2012-11-04T04:13:53Z

my internet connection is kind of spotty, so I'm saving again

JHunter: saving progress again

2012-11-04T04:01:00Z

saving progress again

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 '''Ribonucleic acid''' (RNA) is a family of biomolecules which perform several essential functions within all cells.  As a type of nucleic acid, RNA is structurally and chemically very similar to [[DNA]]; the two largest differences being that the RNA backbone contains ribose instead of 2'-deoxyribose and uses [[uracil]] instead of [[thymine]] as one of its four bases.<ref>Nelson & Cox. (2008). ''Principles of biochemistry''.</ref>
-Unlike DNA, which is primarily used as a template for [[transcription]], RNA molecules perform a diverse set of functions within the cell.  Subsets of RNA are generally classified by their function, which can range from acting as the template for [[translation|protein synthesis]] ("messenger RNA" or "[[mRNA]]") to performing [[ribozyme|enzymatic functions]].  Additionally, many viruses use RNA instead of DNA as their genetic material (e.g. [[retrovirus]]es).
+Unlike DNA, which is primarily used as a template for [[transcription]], RNA molecules perform a diverse set of functions within the cell.  Subsets of RNA are generally classified by their function, which can range from acting as the template for [[Translation (biology)|protein synthesis]] ("messenger RNA" or "[[mRNA]]") to performing [[ribozyme|enzymatic functions]].  Additionally, many viruses use RNA instead of DNA as their genetic material (e.g. [[retrovirus]]es).
 As with DNA, RNAs can exist in single-stranded (annotated "ssRNA") or double-stranded ("dsRNA") forms; however, the vast majority of cellular RNAs are single-stranded.  dsRNAs generally function in post-transcriptional [[gene regulation]] or as viral genetic material.  Targeted degradation of dsRNAs is a major intracellular defence mechanism against viruses.<ref>Alberts et al. (2008). ''Molecular biology of the cell''.</ref><ref>Weaver, Robert F. ''Molecular Biology''. 4th ed. Boston: McGraw-Hill, 2008.</ref>

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-'''Ribonucleic acid''' (RNA) is a family of biomolecules which perform several essential functions within all cells.  As a type of nucleic acid, RNA is structurally and chemically very similar to [[DNA]]; the two largest differences being that the RNA backbone contains ribose instead of 2'-deoxyribose and uses [[uracil]] instead of [[thymine]] as one of its four bases<ref>Nelson & Cox. (2008). ''Principles of biochemistry''.</ref>.
+'''Ribonucleic acid''' (RNA) is a family of biomolecules which perform several essential functions within all cells.  As a type of nucleic acid, RNA is structurally and chemically very similar to [[DNA]]; the two largest differences being that the RNA backbone contains ribose instead of 2'-deoxyribose and uses [[uracil]] instead of [[thymine]] as one of its four bases.<ref>Nelson & Cox. (2008). ''Principles of biochemistry''.</ref>
-Unlike DNA, which is primarily used as a template for [[transcription]], RNA molecules perform a diverse set of functions within the cell.  Subsets of RNA are generally classified by their function, which can range from acting as the template for [[translation|protein synthesis]] ("messenger RNA" or "[[mRNA]]") to performing [[ribozyme|enzymatic functions]].  Additionally, many viruses use RNA instead of DNA as their genetic material (e.g. [[retrovirus|retroviruses]]).
+Unlike DNA, which is primarily used as a template for [[transcription]], RNA molecules perform a diverse set of functions within the cell.  Subsets of RNA are generally classified by their function, which can range from acting as the template for [[translation|protein synthesis]] ("messenger RNA" or "[[mRNA]]") to performing [[ribozyme|enzymatic functions]].  Additionally, many viruses use RNA instead of DNA as their genetic material (e.g. [[retrovirus]]es).
-As with DNA, RNAs can exist in single-stranded (annotated "ssRNA") or double-stranded ("dsRNA") forms; however, the vast majority of cellular RNAs are single-stranded.  dsRNAs generally function in post-transcriptional [[gene regulation]] or as viral genetic material.  Targeted degradation of dsRNAs is a major intracellular defence mechanism against viruses<ref>Alberts et al. (2008). ''Molecular biology of the cell''.</ref><ref>Weaver, Robert F. ''Molecular Biology''. 4th ed. Boston: McGraw-Hill, 2008.</ref>.
+As with DNA, RNAs can exist in single-stranded (annotated "ssRNA") or double-stranded ("dsRNA") forms; however, the vast majority of cellular RNAs are single-stranded.  dsRNAs generally function in post-transcriptional [[gene regulation]] or as viral genetic material.  Targeted degradation of dsRNAs is a major intracellular defence mechanism against viruses.<ref>Alberts et al. (2008). ''Molecular biology of the cell''.</ref><ref>Weaver, Robert F. ''Molecular Biology''. 4th ed. Boston: McGraw-Hill, 2008.</ref>
 ==Structure==
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 Every nucleotide of RNA consists of a ribose molecule with a nitrogenous base attached to its 1' carbon and a phosphate group attached to its 5' carbon.  Individual RNA nucleotides are linked by a [[phosphodiester bond]] between the 3' carbon of one nucleotide's ribose and the 5' carbon on the next.
-The four nitrogenous bases used in RNA are [[adenine]], [[guanine]], [[cytosine]], and [[uracil]].  Adenine and guanine are the ''purine'' bases, cytosine and uracil are the ''pyrimidine'' bases.  Like in DNA, these bases can hybridize through [[hydrogen bond|hydrogen bonds]]; adenine hybridizes with uracil and guanine hybridizes cytosine.
+The four nitrogenous bases used in RNA are [[adenine]], [[guanine]], [[cytosine]], and [[uracil]].  Adenine and guanine are the ''purine'' bases, cytosine and uracil are the ''pyrimidine'' bases.  Like in DNA, these bases can hybridize through [[hydrogen bond]]s; adenine hybridizes with uracil and guanine hybridizes cytosine.
 Hybridization of nucleotides within RNA molecules allows for the formation of ''secondary structures'' such as RNA hairpins, these secondary structures give RNA molecules an overall ''tertiary structure'' which is often essential for the RNA to perform its function.  Additionally, RNAs can hybridize through base pairing with other RNAs or with complementary DNA sequences.
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 ===mRNA===
-''Messenger RNAs'' ([[mRNA]]) are the template molecules which are ''translated'' into [[protein|proteins]] by [[ribosome|ribosomes]].  They are generally synthesized by [[transcription]] of a DNA template (a [[gene]]) by [[RNA polymerase]], although some viral mRNAs are directly transcribed from an RNA template.
+''Messenger RNAs'' ([[mRNA]]) are the template molecules which are ''translated'' into [[protein]]s by [[ribosome]]s.  They are generally synthesized by [[transcription]] of a DNA template (a [[gene]]) by [[RNA polymerase]], although some viral mRNAs are directly transcribed from an RNA template.
-In [[eukaryote|eukaryotes]], nascent RNA transcripts must generally be processed from ''pre-mRNA'' into mature mRNA, via ''RNA processing'', before they are exported from the nucleus to be translated into proteins.
+In [[eukaryote]]s, nascent RNA transcripts must generally be processed from ''pre-mRNA'' into mature mRNA, via ''RNA processing'', before they are exported from the nucleus to be translated into proteins.
 ===rRNA===
-''Ribosomal RNAs'' ([[rRNA]]) are the RNA molecules that form a major component of the [[ribosome|ribosomes]].  There are three rRNAs in [[prokaryote|prokaryotes]] and four rRNAs in [[eukaryote|eukaryotes]] and [[archaea|archaeans]].
+''Ribosomal RNAs'' ([[rRNA]]) are the RNA molecules that form a major component of the [[ribosome]]s.  There are three rRNAs in [[prokaryote]]s and four rRNAs in [[eukaryote]]s and [[archaea]]ns.
 The genes encoding rRNAs are among the most highly conserved (low level of sequence variance between individuals and species) genes in any genome.  As such, rRNA sequences are often used to generate very precise phylogenetic trees.
@@ Line 55: / Line 55: @@
 ===snRNA===
-''Small nuclear RNAs'' ([[snRNA]]) are involved in several different processes that occur within the nucleus, notably [[RNA splicing]] and the regulation of certain [[transcription factor|transcription factors]].  They generally function in complexes with specific proteins; these snRNA and protein complexes are called ''small nuclear ribonucleoproteins'' ("snRNPs", colloquially pronounced "snurps").
+''Small nuclear RNAs'' ([[snRNA]]) are involved in several different processes that occur within the nucleus, notably [[RNA splicing]] and the regulation of certain [[transcription factor]]s.  They generally function in complexes with specific proteins; these snRNA and protein complexes are called ''small nuclear ribonucleoproteins'' ("snRNPs", colloquially pronounced "snurps").
 ==References==

← Older revision		Revision as of 18:53, May 4, 2013
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−	'''Ribonucleic acid''' (RNA) is a family of biomolecules which perform several essential functions within all cells. As a type of nucleic acid, RNA is structurally and chemically very similar to [[DNA]]; the two largest differences being that RNA contains ribose instead of 2'-deoxyribose and uses [[uracil]] instead of [[thymine]] as one of its four bases<ref>Nelson & Cox. (2008). ''Principles of biochemistry''.</ref>.	+	'''Ribonucleic acid''' (RNA) is a family of biomolecules which perform several essential functions within all cells. As a type of nucleic acid, RNA is structurally and chemically very similar to [[DNA]]; the two largest differences being that the RNA backbone contains ribose instead of 2'-deoxyribose and uses [[uracil]] instead of [[thymine]] as one of its four bases<ref>Nelson & Cox. (2008). ''Principles of biochemistry''.</ref>.

	Unlike DNA, which is primarily used as a template for [[transcription]], RNA molecules perform a diverse set of functions within the cell. Subsets of RNA are generally classified by their function, which can range from acting as the template for [[translation\|protein synthesis]] ("messenger RNA" or "[[mRNA]]") to performing [[ribozyme\|enzymatic functions]]. Additionally, many viruses use RNA instead of DNA as their genetic material (e.g. [[retrovirus\|retroviruses]]).		Unlike DNA, which is primarily used as a template for [[transcription]], RNA molecules perform a diverse set of functions within the cell. Subsets of RNA are generally classified by their function, which can range from acting as the template for [[translation\|protein synthesis]] ("messenger RNA" or "[[mRNA]]") to performing [[ribozyme\|enzymatic functions]]. Additionally, many viruses use RNA instead of DNA as their genetic material (e.g. [[retrovirus\|retroviruses]]).

← Older revision		Revision as of 04:32, December 8, 2012
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	[[Category:Genetics]]		[[Category:Genetics]]
	[[Category:Biochemistry]]		[[Category:Biochemistry]]
		+	[[Category:Biology]]

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-'''Ribonucleic acid''' (RNA) is a family of biomolecules which perform several essential functions within all cells.  As a type of nucleic acid, RNA is structurally and chemically very similar to [[DNA]]; the two largest differences being that RNA contains ribose instead of 2'-deoxyribose and uses [[uracil]] instead of [[thymine]] as one of its four bases.
+'''Ribonucleic acid''' (RNA) is a family of biomolecules which perform several essential functions within all cells.  As a type of nucleic acid, RNA is structurally and chemically very similar to [[DNA]]; the two largest differences being that RNA contains ribose instead of 2'-deoxyribose and uses [[uracil]] instead of [[thymine]] as one of its four bases<ref>Nelson & Cox. (2008). ''Principles of biochemistry''.</ref>.
 Unlike DNA, which is primarily used as a template for [[transcription]], RNA molecules perform a diverse set of functions within the cell.  Subsets of RNA are generally classified by their function, which can range from acting as the template for [[translation|protein synthesis]] ("messenger RNA" or "[[mRNA]]") to performing [[ribozyme|enzymatic functions]].  Additionally, many viruses use RNA instead of DNA as their genetic material (e.g. [[retrovirus|retroviruses]]).
-As with DNA, RNAs can exist in single-stranded (annotated "ssRNA") or double-stranded ("dsRNA") forms; however, the vast majority of cellular RNAs are single-stranded.  dsRNAs generally function in post-transcriptional [[gene regulation]] or as viral genetic material.  Targeted degradation of dsRNAs is a major intracellular defence mechanism against viruses.
+As with DNA, RNAs can exist in single-stranded (annotated "ssRNA") or double-stranded ("dsRNA") forms; however, the vast majority of cellular RNAs are single-stranded.  dsRNAs generally function in post-transcriptional [[gene regulation]] or as viral genetic material.  Targeted degradation of dsRNAs is a major intracellular defence mechanism against viruses<ref>Alberts et al. (2008). ''Molecular biology of the cell''.</ref><ref>Weaver, Robert F. ''Molecular Biology''. 4th ed. Boston: McGraw-Hill, 2008.</ref>.
 ==Structure==

@@ Line 51: / Line 51: @@
 ''Short interfering RNAs'' ([[siRNA]]) are short (~21 base pairs), double-stranded RNA molecules which function in a manner similar to microRNAs (described above).
-siRNAs are commonly used in research for targeted gene knockdown (blocking the expression of a specific gene), and they are also used in several gene therapies.
+siRNAs are commonly used in research for targeted gene knockdown (blocking the expression of a specific gene) and they are also used in several gene therapies.
 ==References==

← Older revision		Revision as of 21:07, November 6, 2012
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	The "cloverleaf" tertiary structure of tRNAs is a common textbook example of the link between RNA structure and function.		The "cloverleaf" tertiary structure of tRNAs is a common textbook example of the link between RNA structure and function.

		+	===microRNA===
		+
		+	''Micro RNAs'' ([[microRNA]])are short RNA molecules involved in post-transcriptional [[gene regulation]]. microRNAs work by binding to complementary sequences on target mRNAs; thus targeting the mRNA for degradation via the [[RISC\|RNA-induced silencing complex]] or, less commonly, blocking translation of the mRNA by [[steric hindrance\|steric]] (mechanical) hindrance.
		+
		+	In their mature, functional form, microRNA molecules are 20 to 24 nucleotides long. This length allows for microRNAs to have a very high degree of target specificity (some microRNAs may only have a single target mRNA).
		+
		+	Because the mechanics of [[RNA polymerase]] require a minimum transcript length of about 50-100 nucleotides, precursor microRNAs are at least 80 nucleotides long (most are longer). As such, several different microRNAs are usually derived from a single precursor transcript.
		+
		+	Together with siRNAs, microRNAs are a major component of ''gene regulatory networks'', which allow the cell to rapidly and efficiently respond to environmental stimuli.
		+
		+	===siRNA===
		+
		+	''Short interfering RNAs'' ([[siRNA]]) are short (~21 base pairs), double-stranded RNA molecules which function in a manner similar to microRNAs (described above).
		+
		+	siRNAs are commonly used in research for targeted gene knockdown (blocking the expression of a specific gene), and they are also used in several gene therapies.

	==References==		==References==

@@ Line 15: / Line 15: @@
 ==Function==
-RNA performs a wide variety of functions within the cell.  Types of RNA are specified by the functions that they perform.
+RNA performs a wide variety of functions within the cell.  Types of RNA are specified by the functions that they perform.  More than 21 functional classes of RNA have been identified, the most common types are described below.
 ===mRNA===
@@ Line 30: / Line 30: @@
 The 28S rRNA (23S rRNA in prokaryotes) is a [[ribozyme]], and is responsible for the aminoacyltransferase (polypeptide-lengthening) activity of the ribosome.
 ==References==

← Older revision		Revision as of 04:13, November 4, 2012
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	In [[eukaryote\|eukaryotes]], nascent RNA transcripts must generally be processed from ''pre-mRNA'' into mature mRNA, via ''RNA processing'', before they are exported from the nucleus to be translated into proteins.		In [[eukaryote\|eukaryotes]], nascent RNA transcripts must generally be processed from ''pre-mRNA'' into mature mRNA, via ''RNA processing'', before they are exported from the nucleus to be translated into proteins.
		+
		+	===rRNA===
		+
		+	''Ribosomal RNAs'' ([[rRNA]]) are the RNA molecules that form a major component of the [[ribosome\|ribosomes]]. There are three rRNAs in [[prokaryote\|prokaryotes]] and four rRNAs in [[eukaryote\|eukaryotes]] and [[archaea\|archaeans]].
		+
		+	The genes encoding rRNAs are among the most highly conserved (low level of sequence variance between individuals and species) genes in any genome. As such, rRNA sequences are often used to generate very precise phylogenetic trees.
		+
		+	The 28S rRNA (23S rRNA in prokaryotes) is a [[ribozyme]], and is responsible for the aminoacyltransferase (polypeptide-lengthening) activity of the ribosome.

	==References==		==References==

← Older revision		Revision as of 04:01, November 4, 2012
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	Hybridization of nucleotides within RNA molecules allows for the formation of ''secondary structures'' such as RNA hairpins, these secondary structures give RNA molecules an overall ''tertiary structure'' which is often essential for the RNA to perform its function. Additionally, RNAs can hybridize through base pairing with other RNAs or with complementary DNA sequences.		Hybridization of nucleotides within RNA molecules allows for the formation of ''secondary structures'' such as RNA hairpins, these secondary structures give RNA molecules an overall ''tertiary structure'' which is often essential for the RNA to perform its function. Additionally, RNAs can hybridize through base pairing with other RNAs or with complementary DNA sequences.
		+
		+	==Function==
		+
		+	RNA performs a wide variety of functions within the cell. Types of RNA are specified by the functions that they perform.
		+
		+	===mRNA===
		+
		+	''Messenger RNAs'' ([[mRNA]]) are the template molecules which are ''translated'' into [[protein\|proteins]] by [[ribosome\|ribosomes]]. They are generally synthesized by [[transcription]] of a DNA template (a [[gene]]) by [[RNA polymerase]], although some viral mRNAs are directly transcribed from an RNA template.
		+
		+	In [[eukaryote\|eukaryotes]], nascent RNA transcripts must generally be processed from ''pre-mRNA'' into mature mRNA, via ''RNA processing'', before they are exported from the nucleus to be translated into proteins.

	==References==		==References==