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14 Cards in this Set
- Front
- Back
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How can gene expression be controlled and state two examples. |
Regulating access to DNA ex. Acetylation of histones and methylation of DNA |
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What does the Acetylation of histones proteins impact? |
How tightly DNA is coiled. |
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Where is DNA wrapped around histone proteins |
in the nucleus (DNA+ Protein = chromatin) |
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What does it mean when methylation of DNA on "CpG Islands" prevent access to DNA |
no transcription |
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What works together to control whether DNA is available to be transcribed? examples of it being acetylation and methylation. |
Epigenetic tags |
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Define epigenetic's. |
refers to horrible changes in gene expression that are not due to changes in DNA sequences themselves. |
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Give an example of how epigenetic tags are susceptible to environmental influences. |
BPA and Mice--> Genetically identically identical but moms different diets Nurturing of pups--> Impacts methylation and pup behavior (stress response) Many humans neurodegenerative diseases are linked to changes in epigenetic tags |
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Define level 2: Initiation of Transcription |
If the DNA is accessible transcription can be initiated through the recruitment of transcription factors to the promoter. |
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How are eukaryotic genes organized differently than prokaryotic genes aside from the promoter? |
There are regulatory sequences that are very far away from the promoter. ( Enhancer elements) |
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How does this imitation of transcription work in eukaryotic cell? |
Activator proteins (a type of transcription factor) binds to enhancer elements--> DNA is bent --> General transcription factors coupled with Mediator proteins interact with activators to recruit RNAP to promoter. |
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What causes different cells to look differently and do different jobs? |
Different activators binding to their enhancer elements control the expression of different genes. |
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Give examples of what causes different cells to look differently and do different jobs? |
In liver cells: Activators are made that bind enhancer of albumin gene and in lens cell activators are made that bind to enhancer crystalline gene. |
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How are scientist able to control when and where genes are expressed? |
by manipulating genes by putting transcriptional units together with different regulatory sequences. |
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Give an example of of scientist are able to control gene expression. |
Making human protein in goat milk- use goat regulatory sequence from mammary gland to control expression of human antithrombin protein Making flies with eyes on their legs- use regulatory sequence from a gene expressed to fly legs to control expression of the eyeless gene. |
