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27 Cards in this Set
- Front
- Back
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What is the purpose of gene regulation? It occurs at the level of _______.
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Controls the genes; ability to turn them on and off. Transcription |
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Regulatory sequences of DNA are called_________ and ______.
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What is the purpose of the operon?
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To regulate protein production in Prokaryotes |
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In an operon, what is the function of the promoter?
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It is the binding site for RNA polymerase during transcription. |
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In an operon, the repressor protein binds to the_____ and obstructs the _____.
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Operator, Promoter
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What effect does the inducer have on an inducible operon?
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The inducer binds to the repressor which makes it unable to bind to the operator of the operon. So when the represspor is inavtive the operator is not obstructed and operon can produce its mRNA and this its proteins. Operon is "on" |
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What is (are) effector molecule(s) in the operon model?
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They interact with the repressor, There are two kinds inducer and corepressor |
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What is an example of an inducible operon? Briefly describe how it functions.
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lac operon. Purpose of this operon is to produce enzymes that break up lactose. The repressor molecule is active when the regulator gene produces it. The repressor will inhibit the production of these enzymes. Lactose(allolactose) is the inducer molecule- it makes the repressor inactice. By making the repressor inactive, it causes the opero to turn on. With the operon on, the enzymes needed to break up lactose will be produced.
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What is an example of a repressible operon? Briefly describe how it functions.
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trp operon. Purpose of this operon is to produce the enzymes that synthesize the amino acid tryptophan. The repressor is produced inactive. It only represses the operon if the corepressor is present. Tryptophan itself is the corepressor. If tryptophan is present (and hence doesnt need to be made anymore) it binds to the repressor and turns the operon off. |
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. What is positive regulation of a gene?
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Causes the gene to be more efficient; performs transcription faster. |
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Positive regulation of protein synthesis occurswhen what complex binds to the promoter?
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CAP-cAMP |
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In addition to promoters, eukaryotic genes also have_________ that enhance transcription. Describe them and how they function
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enhancers
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What is the difference between chromatin andchromatid?
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Chromatin b |
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List the levels a chromosome goes through as itcondenses
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Nucleosomes, 30 nm fiber, Looped Domains, condensed chromosomes |
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The nucleosome core contains ________ molecules;two each of which molecules?
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Two molecules each of histones H2A, H2B, H3 and H4 around which the DNA filament is wrapped twice. |
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Even though all the genetic material is found in eacheukaryotic cell of a multicellular organism, some of the DNA in each cell is not expressed. This is called ____________ or______________.
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Differentiation, Specialization
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What are transcription factors, and what do they do?
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Proteins that bind to specific DNA sequences and/or other regulatory proteins to cause genes to be activated or inactivated |
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What is the relationship between cytokines andgene regulation?
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Cytokines are protein regulator proteins that are released from one cell and travel to another. When they reach their "target" cell they control (turn on and off) processes int that cell such as cell respiration and cell division. |
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What is the relationship between ethylene andgene regulation?
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It is a molecule in plants that controls the production of certain enzymes within plants.
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. Describe 2 examples of how environmentalfactors can influence gene expression.
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1. Height and weight in human are affected by nutrition, amount of sleep, amount of stress, can cause mitosis genes to be activated or inactivated. |
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. What is the relationship between homeoticgenes and gene regulation?
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Homeotic genes contain information about mapping out the basic body plan of that organism, and these genes make sure that during differentiation the correct genes are turned off or on in the correct order. |
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. What is the relationship between RNAi and generegulation?
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There are different kinds of RNA that are involved in gene regulation. RNAi is a process in which RNA molecules inhibit gene expression.
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What is the relationship between apoptosis, HOXgenes, and gene regulation?
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Apoptosis is the programmed cell death which play a role in differentiation, HOX genes are regultor genes that are responsible for making sure apoptosis occurs at the right time in the right cells. |
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What do the different forms of DNA, the degree ofcondensation, methylation of chromosomes, and specific binding proteins all have in common?
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They are all examples of epigenetics involved in the regulation of genes in eukaryotes |
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. Whichtype of chromatin is dispersed and accessible for transcription?
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Which type of chromatin is inactive? Why can transcription not occur on this typeof chromatin?
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Heterochromatin, transcription cannot occur because RNA polymerase can't get to the DNA strand |
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What is epigenetics?
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Refers to when external modification to the DNA turn genes "on" or "off" |
