Gene: Difference between revisions
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A gene is a unit of | A gene is a unit of genetic information that is trancribed into m[[RNA|RNA]] and then translated to create a polypeptide chain of a specific sequence. [[Alleles|Alleles]] are different forms of a gene, and are present in a [[diploid|diploid]] cell on both of the [[Homology|homologous]] chromosomes at the exact same [[gene loci|loci]]. They are variants because of [[mutations|mutations]]; random [[Nitrogenous base|nitrogenous base ]]sequence changes that lead to different [[Nucleotide|nucleotide sequences]]. A different base sequence can therefore code for a different [[Codon|codon]] on the [[MRNA|mRNA]] transcribing molecule, and therefore lead to the binding of a different [[anticodon|anticodon]] on a [[tRNA|tRNA]] molecule, producing an alternate sequence of amino acids during the process of [[translation|translation]] on the [[ribosome|ribosome]]. This alternate sequence of amino acids may produce a different protein to the non-mutated form of the gene. In this way, genes are vital coding units for the [[Proteins|proteins]] of the cell.<br> | ||
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=== References === | === References <ref>Bruce Alberts et al.(2002)'Molecular Biology of the Cell' -- 4th ed. New York, Garland Science.</ref> === | ||
Revision as of 16:34, 27 November 2010
A gene is a unit of genetic information that is trancribed into mRNA and then translated to create a polypeptide chain of a specific sequence. Alleles are different forms of a gene, and are present in a diploid cell on both of the homologous chromosomes at the exact same loci. They are variants because of mutations; random nitrogenous base sequence changes that lead to different nucleotide sequences. A different base sequence can therefore code for a different codon on the mRNA transcribing molecule, and therefore lead to the binding of a different anticodon on a tRNA molecule, producing an alternate sequence of amino acids during the process of translation on the ribosome. This alternate sequence of amino acids may produce a different protein to the non-mutated form of the gene. In this way, genes are vital coding units for the proteins of the cell.
References [1]
- ↑ Bruce Alberts et al.(2002)'Molecular Biology of the Cell' -- 4th ed. New York, Garland Science.