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43 Cards in this Set
- Front
- Back
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Cell Enzyme Regulation |
A cell can regulate the production of enzymes by - Feedback Inhibition -Gene Regulation |
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Operator |
The regulatory switch is a segment of DNA called the operator which is positioned with in the promoter
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Operon |
is the entire stretch of DNA which includes -promoter -operator -structural genes |
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repressor |
The operon can be switched off by this protein |
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regulatory gene |
The repressor is a product of this and can be in an inactive or an active form depending on the presence of other molecules such as the repressor or the inducer |
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Corepressor |
is a molecule that cooperates with a repressor protein to switch the operon off |
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tryptophan |
repressible system Ecoli synthesizes this amino acid tryp- the corepressor |
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Inducible Operon |
operon that is usually off an inducer can activate the system |
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lac Operon |
Inducible operon system creates the enzyme lactase which hydrolyzes lactose |
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differential gene expression |
Differences between cell types result from this the expression of different genes by cells with the same genome |
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Stages in gene expression that can be regulated |
Transcription, mRNA processing, Transport to the cytoplasm, Degredation of the mRNA |
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Heterochromatin |
genes with highly condensed heterochromatin are usually not expressed |
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Histone Acetylation |
acetyl groups are attached to positively charged lysines in histones this loosens the chromatin and promotes initiation of transcription |
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DNA methylation |
The addition of methyl groups can condense chromatin and lessen the likelihood of transcription/gene expression |
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DNA phosphorylation |
the addition of phosphate groups next to a methylated amino acid can loosen chromatin |
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DNA methylation |
to certain bases in DNA this can cause reduced transcription this can cause longterm inactivation of genes in cellular differentiation methylation regulates expression of either maternal or paternal allels and development |
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Epigenetic inheritence |
the inheritance of traits transmitted by mechanisms not directly involving the nucleotide sequence -DNA methylation |
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Chromatin Modifying Enzymes |
provide initial control of gene expression by making a region of DNA either more or less able to bind to the transcription machinery |
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Control elements |
segments of noncoding DNA that serve as binding sites for transcription factors help regulate transcription
proximal and distal (enhancer) |
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enhancers |
Distal control elements are groupings which are far away from a gene or even located in an intron |
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an activator is a protein that binds to an enhancer and stimulates transcription of a gene |
2 domains- one that binds DNA and a second that activates transcription |
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alternative RNA splicing |
different mRNA molecules are produced from the same primary transcript, depending on which segments are treated as exons and which are treated as introns |
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ubiqutin |
these are placed on mRNAs to signal for mRNA degredation |
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proteasomes |
degrade proteins |
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non-protein coding DNA |
consists of genes for RNA such as rRNA and tRNA |
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ncRNAs |
a significant amount of the genome
regulate gene expression at mRNA translation and chromatin configuration |
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microRNAs |
are single stranded RNA molecules that can bind to mRNA -degrade or block transcription -1/2 of DNA expression is regulated by microRNA |
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siRNA |
small interfering RNA are similar to microRNA in size and function cause RNAi -RNA interference used in lab to disable and observe function of genes |
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zygote to adult |
cell division and cell differentiation and morphogenesis |
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morphogenesis |
the physical process that gives an organism its shape |
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differential gene expression |
results from genes being regulated differently in each cell type |
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cytoplasmic determinants |
are maternal substances in the egg that influence early development -leads to diff. gene expression |
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induction |
signal molecules from embryonic cells cause transcriptional changes in nearby cells
interactions between cells induce differntial of specailized cell types |
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Determination |
commits a cell to its final fate precedes differentiation marked by the production of tissue specific proteins |
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Pattern formation |
is the development of a spatial organization of tissues and organs begins with egg polarity genes |
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positional information |
the molecular ques that control pattern formation tells a cell its location relative to the body axes and to neighboring cells |
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oncogenes |
cancer causing genes |
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protoncogenes |
are the corresponding normal cellular genes that are responsible for normal cell growth and division
proto to onco= abnormal cell cycle |
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proto to oncogene |
movement of DNA within the genome if near active promoter transcript will increase
amplification of proto onco increases copies of a gene
point mutations in p.o. or conrol element cause an increase in gene expression |
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tumor supressor genes |
help prevent uncontrolled cell growth -repair damage to DNa -control cell adhesion -inhibit the cell cyle in the cell signaling pathway mutations to these may cause cancer
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ras gene |
mutations to this tumor suppressor gene are common in humans can lead to hyperactive ras protein and increased cell division |
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p53 |
tumor supressor gene prevents a cell from passion mutations due to DNA damage this mutation prevents supression of the cell cycle |
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APC (adenomatous polyposis coli) |
common in individuals who develop colon and rectum cancer indivdiuals can inherit oncogenes and mutant allells of tumor supressor genes |
