Difference between revisions of "RNA"
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A '''Ribonucleic acid''' (RNA) is a molecule found in all cells, comprised of many individual units of [[nucleic acid]]. It differs from DNA ([[deoxyribonucleic acid]]) in that it only contains a single, not double strand, and substitutes [[uracil]] for [[thymine]]. The sugar backbone of RNA is also conposed of ribose (DNA contains deoxyribose). RNAs fall into several different categories, depending on function. | A '''Ribonucleic acid''' (RNA) is a molecule found in all cells, comprised of many individual units of [[nucleic acid]]. It differs from DNA ([[deoxyribonucleic acid]]) in that it only contains a single, not double strand, and substitutes [[uracil]] for [[thymine]]. The sugar backbone of RNA is also conposed of ribose (DNA contains deoxyribose). RNAs fall into several different categories, depending on function. | ||
| − | The primary role of mRNA in is to transfer a copy of the information coded in DNA to a [[ribosome]] to be expressed as a protein, using a form of RNA known as messenger RNA ([[mRNA]]). mRNA in eukaryotes undergoes spicing after transcription from DNA to remove [[introns]] or to use alternative splicing to create a different gene product. | + | The primary role of mRNA in is to transfer a copy of the information coded in DNA to a [[ribosome]] to be expressed as a protein, using a form of RNA known as messenger RNA ([[mRNA]]). mRNA in eukaryotes undergoes spicing after transcription from DNA to remove [[introns]] or to use alternative splicing to create a different gene product. Alternatively-spliced transcripts can also express the same protein, but at different levels, due to the removal or addition of regulatory sequecnces. |
The main role of [[tRNA]], or transfer RNA is to carry an amino acid to the mRNA (while the mRNA is in the ribosome) during translation of the mRNA into a protein. | The main role of [[tRNA]], or transfer RNA is to carry an amino acid to the mRNA (while the mRNA is in the ribosome) during translation of the mRNA into a protein. | ||
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Purification of RNA is problematic as enzymes that degrade RNA ([[RNases]]) are ubiquitous. Successful RNA purification depends on degradation of the DNA template used via DNase and avoidance of RNase using sterile technique. | Purification of RNA is problematic as enzymes that degrade RNA ([[RNases]]) are ubiquitous. Successful RNA purification depends on degradation of the DNA template used via DNase and avoidance of RNase using sterile technique. | ||
| − | The polio virus is an example of an organism which contains only RNA to carry its genetic information. | + | The polio virus is an example of an organism which contains only RNA to carry its genetic information. Some [[protists]] such as ''Paramecium'' carry similar RNA genes in structures called micronuclei. These are involved in mating and replicate independently from the main cell nucleus. |
==Prebiotic RNA Polymerization== | ==Prebiotic RNA Polymerization== | ||
Revision as of 15:42, July 27, 2008
A Ribonucleic acid (RNA) is a molecule found in all cells, comprised of many individual units of nucleic acid. It differs from DNA (deoxyribonucleic acid) in that it only contains a single, not double strand, and substitutes uracil for thymine. The sugar backbone of RNA is also conposed of ribose (DNA contains deoxyribose). RNAs fall into several different categories, depending on function.
The primary role of mRNA in is to transfer a copy of the information coded in DNA to a ribosome to be expressed as a protein, using a form of RNA known as messenger RNA (mRNA). mRNA in eukaryotes undergoes spicing after transcription from DNA to remove introns or to use alternative splicing to create a different gene product. Alternatively-spliced transcripts can also express the same protein, but at different levels, due to the removal or addition of regulatory sequecnces.
The main role of tRNA, or transfer RNA is to carry an amino acid to the mRNA (while the mRNA is in the ribosome) during translation of the mRNA into a protein.
The main role of rRNA or ribosomal RNA is to form the ribosome. RNA that has catalytic properties (such as the ribosome) is referred to as a ribozyme.
Purification of RNA is problematic as enzymes that degrade RNA (RNases) are ubiquitous. Successful RNA purification depends on degradation of the DNA template used via DNase and avoidance of RNase using sterile technique.
The polio virus is an example of an organism which contains only RNA to carry its genetic information. Some protists such as Paramecium carry similar RNA genes in structures called micronuclei. These are involved in mating and replicate independently from the main cell nucleus.
Prebiotic RNA Polymerization
From Clays
Research from Rensselaer Polytechnic Institute suggests that the formation of long strands of RNA may have been catalyzed by clays such as montmorillonite. The charged clay surface attracts the nucleotides and the increased local concentration of nucleotides causes bond formation between nucleotides, forming a polymer of RNA.[1][2][3]
From Ice
Strands of RNA have been shown to form in salty ice water. David Deamer's lab at the University of California at Santa Cruz has found that the process of freezing a dilute solution of RNA nucleotides causes the nucleotides to become concentrated as ice crystals form, eventually resulting in the formation of strands of RNA. [4]
References
- ↑ http://www.rpi.edu/dept/chem/chem_faculty/profiles/pdfs/ferris/Royal_Soc..pdf
- ↑ http://www.rpi.edu/dept/chem/chem_faculty/profiles/pdfs/ferris/Alders.Mass_Spec.pdf
- ↑ http://www.rpi.edu/dept/chem/chem_faculty/profiles/pdfs/ferris/Huang_MS_JACS_2006%203.pdf
- ↑ J. P. Dworkin, D. W. Deamer, S. A. Sandford, and L. J. Allamandola. 2001. Self-assembling amphiphilic molecules: Synthesis in simulated interstellar/precometary ices. Proc. Natl. Acad. Sci. USA 98:815-819.
