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Types of control in Eukaryotes

Types of control in Eukaryotes - Heterochromatin is tightly...

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Types of control in Eukaryotes Gene expression in eukaryotes is controlled by a variety of mechanisms that range from those that prevent transcription to those that prevent expression after the protein has been produced. The diagram below shows five kinds of general mechanisms that can be used. Transcriptional - These mechanisms prevent transcription. Posttranscriptional - These mechanisms control or regulate mRNA after it has been produced. Translational - These mechanisms prevent translation. They often involve protein factors needed for translation. Posttranslational - These mechanisms act after the protein has been produced. Transcriptional These mechanisms prevent mRNA from being synthesized. Heterochromatin and Euchromatin
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Unformatted text preview: Heterochromatin is tightly wound DNA and visible during interphase. It is inactive because DNA cannot be transcribed while it is tightly wound. Euchromatin is not tightly wound. It is active. Acetylation/deacetylation of DNA Condensation of DNA involves coiling around proteins called histones. Acetylation is when acetyl groups (-COCH 3 ) are attached to lysines in the histone tails. This reduces condensation and promotes transcription because the transcription machinery has better access to the DNA. The addition of methyl groups (-CH 3 ) also promotes condensation. The addition of a phosphate group to an amino acid that is next to a methylated amino acid results in less condensation....
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