BIO 122 Lecture Notes - Lecture 9: Post-Translational Modification, Central Dogma Of Molecular Biology, Alternative Splicing
Prior to Week 9 Class 1 – Chapter 19
Know
• What gene expression means
o What genes are transcribed and translated to be expressed in the cell
• That bacteria and eukaryotes can control gene expression through transcriptional, translational, and post-
translational ways
• That eukaryotes can also more tightly regulate transcription, post-transcription, translation, and post-
translation
• What basal transcription factors are
o They bind to DNA to begin transcription
o What TATA-box binding protein (TBP) is
▪ Binds to tata box and allows rna pol to bind to dna
o That they bind at the transcriptional start site
• What regulatory sequences are
o Allow regulatory proteins to bind and change gene transcription
o What promoter-proximal means/refers to
▪ Upstream of promoter and transcriptional site
o What enhancer/silencer regions of DNA are and that they regulate gene expression by controlling
efficiency or speed of transcription
▪ Enhancer
• Encourages transcription
• Bound by activators
▪ Silencer
• Discourages transcription
• Bound by repressors
• What a nucleosome is and that it is made of histones
o Nucleosome
▪ Dna – histone complex
• What the 30nm chromatin fiber refers to
o nucleosome
• What terms chromatin, euchromatin, heterochromatin refer to and what that means for access for
transcription
o Chromatin
▪ Dna – histone
o Euchromatin
▪ Decondensed
▪ Easy transcription
o Heterochromatin
▪ Condensed
▪ Difficult transcription
• What histone acetyl transferases (HATs) do
o Add (-) acetyl groups to histones
▪ Neutralizes histone’s positive charges
▪ Makes dna-histone interaction more difficult
▪ Causes decondensation
▪ Eases transcription
• What histone deacetyl-transferases (HDACs) do
o Remove (-) acetyl group to histones
▪ Makes histone charge more positive
▪ Makes dna-histone interaction easier
▪ Causes condensation
▪ Makes transcription harder
• What RNA interference is and what miRNAs are
o causes silencing of gene by
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