Term
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Definition
| encodes proteins required to import and digest the disaccharide lactose |
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Term
| regulation of the Lac and tryptophan operons involves negative control of genes. Explain this process. |
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Definition
the operons are switched off by the active form of the repressor.
Negative control involves the binding of a repressor to the operator to prevent transcription.
they are shut off by an active repressor |
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Term
| eukaryotic gene regulation involved which type of control? |
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Definition
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Term
- The Lac operon is also an example of a positive control system. What is it turned on by?
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Definition
the cAMP-CAP complex
positive control is when the activator turns the operon "on" |
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Term
| What is differential gene expression? |
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Definition
| the expression of different genes by cells with the same genome...differences between cell types result from this |
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Term
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Definition
region of a chromosome that remains unusually condensed and transcriptionally inactive during interphase
highly packed.... genes are usually not expressed |
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Term
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Definition
| one of a group of abundant basic proteins, rich in arginine and lysine that are associated with DNA in chromosomes to form nucleosomes...chemical modifications to histones and DNA influence chromatin structure and gene expression |
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Term
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Definition
| complex of DNA, histones, and non-histone proteins found in the nucleus of a eucaryotic cell. The material of which chromosomes are made. |
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Term
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Definition
acetyl groups attached to positively charged lysines (an essential amino acid found in proteins) in histone tails, it loosens the chromatin structure and promotes initiation of transcription
the acetylation state of histones acts as a signal that attracts other proteins that activate or repress transcription |
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Term
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Definition
| methyl groups attached to histone tails promote chromatin condensation and less transcription |
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Term
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Definition
methylation regulates expression of either maternal or paternal alleles of certain genes at the start of development
Genomic imprinting is a genetic phenomenon by which certain genesare expressed in a parent-of-origin-specific manner. It is an inheritance process independent of the classical Mendelian inheritance. Imprinted genes are either expressed only from the allele inherited from the mother (e.g. H19 or CDKN1C), or in other instances from the allele inherited from the father (e.g. IGF-2). |
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Term
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Definition
inheritance that is superimposed on the information inherited in the DNA sequence itself. Often, information in the form of a particular type of chromatin structure
inheritance of traits transmitted by mechanisms not directly involving the nucleotide sequence |
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Term
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Definition
| segments of noncoding DNA which help regulate transcription by binding certain proteins |
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Term
| What are required to initiates transcription? |
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Definition
| transcription factors.... they facilitate binding of RNA polymerase |
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