Term
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Definition
-Cluster of related genes controlled by on/off switch
-Switch is DNA segment called operator
-Operon is entire DNA strand: operator, promoter and genes |
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Term
1) Promoter
2) Operator
3) Repressor
4) Corepressor
5) Regulatory gene |
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Definition
1) Region of DNA that facilitates transcription
2) Regulatory switch, usually within promoter
3) Switches off the operon
4) Molecule that cooperates to switch off operon
5) A gene involved in the expression of one or more other genes; may code for a repressor or activator |
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Term
Repressible operon
Inducible operon |
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Definition
R - is usually on, binding of a repressor shuts off transcription
I - usually off, inducer inactivates the repressor, turns on transcription |
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Term
| Inducible enzymes usually in catabolic pathways (induced by chemical sugnal) |
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Definition
| Repressible enzymes usually in anabolic pathways (repressed by high levels of product) |
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Term
| Differential gene expression |
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Definition
- Expression of different genes by cells with the same genome
- Causes difference in cell types |
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Term
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Definition
| - Chemical modifications to histones and DNA of chromatin influence structure and gene expression |
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Term
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Definition
| acetylation - loosens chromatin, promotes transcription |
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Term
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Definition
methylation - condense chromatin, can cause logn-term inactivation of genes
phosphorylation - next to methylated amino acid can loosen chromatin |
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Term
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Definition
Def: Inheritance of mechanisms not directly involving the nucleotide sequence
- DNA modifications do not alter DNA sequence
- Modifications may be passed to future cell generations |
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Term
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Definition
Def: segments of DNA that help regulate transcription by binding certain proteins
- Critical to the precise regualtion of differentiation |
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Term
Transcription Factors
- Enhancers
- Proximal and Distal |
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Definition
- RNA polymerase requires assistance of proteins called transcription factors
- Proximal = close to promoter
- Distal = far from gene or in intron
- Enhancers bind to distal control elemenets |
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Term
| Coordinately Controlled Genes in Eukaryotes |
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Definition
- Each of the coordinately controlled genes has a promoter and control elements
- May be located on different chromosomes, but has the same control elements
- Copies of activators promote simultaneous transcription of the genes |
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Term
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Definition
- Lifespan of mRNA is key to determining protein synthesis
- Determined in part by sequences in leader and trailer regions |
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Term
Protein Processing
Proteasomes |
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Definition
General: cleavage, addition of chemicals groups and degradation
P - protein complexes that bind protein molecules and degrade them |
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Term
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Definition
MicroRNA (miRNA)
Small Interfering RNA (siRNA)
Regulate gene epxression at translation and chromatin configuration |
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Term
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Definition
- Single stranded RNA molecules that can bind to mRNA
- Degrade mRNA or block its translation |
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Term
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Definition
- Similar to miRNA, but different RNA precursors
- Play a role in heterochromatin formation, can block large regions of chromosome
- May also block transcription |
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Term
Cell Differentiation
Morphogenesis |
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Definition
C - Process by which cells become specialized in structure and function
M - Physical process that give an organism its shape |
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Term
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Definition
Def: Maternal substances in the egg that influence early development
- RNA, proteins and other that are distributed unevenly in the unfertilized egg
-As zygote divides, cells contain different determinants |
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Term
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Definition
Def: signal molecules from embryonic cells cause transcriptional changes in nearby target cells
- Source of developmental information (environment around the cells) |
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Term
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Definition
- Commits a cell to its final fate
- Precedes differentiation
- Differentiation marked by the production of tissue-specific proteins |
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Term
Pattern formation
Positional information |
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Definition
Def: development of a spatial organization of tissues and organs (begins in animals with major axes)
Def: molecular cues that control pattern formation. tell a cell location relative to axes |
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Term
Maternal effect genes
Egg-polarity genes |
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Definition
M - encode for cytoplasmic determinants that initially establish axes
E - another name for M |
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