General Biology, Week 8 notes
General Biology, Week 8 notes BIOL 1005
Popular in General Biology
Popular in Science
This 3 page Class Notes was uploaded by Megan Wiggs on Monday October 10, 2016. The Class Notes belongs to BIOL 1005 at Virginia Polytechnic Institute and State University taught by MV lipscomb in Fall 2016. Since its upload, it has received 2 views. For similar materials see General Biology in Science at Virginia Polytechnic Institute and State University.
Reviews for General Biology, Week 8 notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 10/10/16
9.5 How Genes Are Regulated For a cell to function properly, necessary proteins, must be synthesized at the proper time. All organisms and cells control/regulate the transcription & translation of their DNA into protein. Gene expression: the process of turning a gene to produce RNA and protein Each cell controls when and how its genes are expressed: - Must be a mechanism to control when a gene is expressed to make RNA and protein - How much of the protein is made - When it is time to stop making that protein because it is no longer needed Cells in multicellular organisms are specialized: - Different tissues look very different and perform different functions All cells have basic functions: - Converting energy into sugar molecules into energy in ATP - Turn on or off certain genes in response to changes/development Unicellular organisms also turn on and off genes in response to demands on environment Prokaryotic versus Eukaryotic Gene Expression The primary method to control what type & how much protein is expressed in prokaryotic cell is through the regulation of DNA transcription into RNA - All subsequent steps happen automatically - In prokaryotic cells control of gene expression is almost entirely at the transcription level Eukaryotic cells, have intercellular organelles and are much more complex - transcription occurs only within the nucleus - translation only occurs outside the nucleus in the cytoplasm - Regulation may occur when the DNA is uncoiled and loosened from nucleosomes to bind transcription factors (epigenetic level): o when the RNA is transcribed (transcriptional level), o when RNA is processed and exported to the cytoplasm after it is transcribed (post-transcriptional level), o when the RNA is translated into protein (translational level), o or after the protein has been made (post- translational level). Differences in the regulation of Gene Expression of Prokaryotic and Eukaryotic Organisms Prokaryotic organisms Eukaryotic organisms Lack nucleus Contain nucleus RNA transcription and RNA transcription occurs prior to protein protein translation translation, and it takes place in the nucleus. occur almost RNA translation to protein occurs in the simultaneously cytoplasm. RNA post-processing includes addition of a 5' cap, poly-A tail, and excision of introns and splicing of exons. Gene expression is Gene expression is regulated at many levels regulated primarily at (epigenetic, transcriptional, post- the transcriptional transcriptional, translational, and post- level translational) Summary All somatic cells within an organism contain the same DNA, they express different proteins Prokaryotic: express the entire DNA they encode in every cell, not necessarily at the same time (proteins are expressed only when needed) - Gene expression is only regulated at the transcriptional level Eukaryotic: very complex, type and amount of protein is regulated by controlling gene expression - DNA RNA Proteins - Regulated at the epigenetic, transcriptional, post- transcriptional, translational, & post-translational levels alternative RNA splicing a post-transcriptional gene regulation mechanism in eukaryotes in which multiple protein products are produced by a single gene through alternative splicing combinations of the RNA transcript epigenetic describing non-genetic regulatory factors, such as changes in modifications to histone proteins and DNA that control accessibility to genes in chromosomes gene expression processes that control whether a gene is expressed post-transcriptional control of gene expression after the RNA molecule has been created but before it is translated into protein post-translational control of gene expression after a protein has been created
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'