Control of Gene Expression
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| 318832416 | positive control | increases the frequency of initiation | |
| 318832417 | negative control | decreases the frequency of initiation | |
| 318832418 | repressors | proteins that mediate negative control that bind to operators | |
| 318832419 | operators | regulatory sites on DNA | |
| 318832420 | activators | regulatory, alosteric proteins that mediate positive control | |
| 318832421 | lac operon | consists of a promoter, an operator and 3 genes that encode protein required for the metabolism of lactose | |
| 318832422 | trp operon | encodes the enzymes necessary to synthesize tryptophan | |
| 318832423 | induction | when enzymes for a certain pathway are produced in response to a substrate | |
| 318832424 | repression | when bacteria capable of making biosynthetic enzymes don't produce them | |
| 318832425 | catabolic pathways | breakdown molecules | |
| 318832426 | anabolic pathways | build up molecules | |
| 318965664 | regulatory proteins | modulate the ability of RNA polymerase to bind to the promoter | |
| 318965665 | homeostasis | metabolic equilibrium actively maintained by several complex biological mechanisms that operate via the autonomic nervous system to offset disrupting changes | |
| 318965666 | apoptosis | programmed cell death | |
| 318965667 | major groove | Larger groove that spirals around the DNA double helix. Provides a location where a protein can bind to a particular sequence of bases and affect the expression of a gene. | |
| 318965668 | DNA-binding motifs | a region found in a regulatory protein that is capable of binding to a specific base sequence in DNA | |
| 318965669 | helix turn helix | dna binding motif which has two alpha helices connected by a turn | |
| 318965670 | recognition helix | recognizes and makes contact with a base sequence along the major groove of DNA Hydrogen bonding between an α-helix and nucleotide bases is one way a transcription factor can bind to DNA | |
| 318965671 | homeodomain motif | a special class of helix turn helix motifs found in regulatory proteins that control development in eukaryotes | |
| 318965672 | homeodomain | 60 amino acid protein, binds to DNA and regulates expression | |
| 318965673 | zinc finger motif | A type of DNA-binding motif in regulatory proteins that incorporates zinc atoms in its structure. | |
| 318965674 | leucine zipper motif | A motif in regulatory proteins in which two different protein subunits associate to form a single DNA-binding site; the proteins are connected by an association between hydrophobic regions containing leucines (the "zipper"). | |
| 318965675 | derepressed | when tryptophan levels fall and the repressor alone cannot bind to the operator, allowing expression of the operon | |
| 318965676 | general transcription factors | any of a group of transcription factors necessary for the formation of an initiation complex by RNA polymerase II at a promoter. This allows a basal level that can be increased by the action of specific factors | |
| 318965677 | specific transcription factors | any of a great number of transcription factors that act in a time- or tissue-dependent manner to increase DNA transcription above the basal level | |
| 318965678 | enhancers | a site of regulatory protein binding on the DNA molecule distant from the promoter and start site for a gene's transcription | |
| 318965679 | coactivators and mediators | link transcription factors to RNA polymerase II | |
| 318965680 | transcription complex | the whole complex of transcription factors and RNA polymerase II bound to the promoter | |
| 318965681 | transcription activators | some of theses alter chormatin structure | |
| 318965682 | histone | protein molecule around which DNA is tightly coiled in chromatin | |
| 318965683 | chromatin-remodeling complexes | use energy from ATP to alter chromatin structure | |
| 318965684 | mRNA | must be transported out of the nucleus for translation | |
| 318965685 | translation repressor proteins | shut down translation by binding to the beginning of the transcript so that it cannot attach to the ribosome | |
| 318965686 | proteases | enzymes that degrade proteins by breaking peptide bonds, converting a protein into its constituent amino acids | |
| 318965687 | ubiquitin | Small protein that is linked to other proteins as a way of marking the targeted protein for degradation by proteasomes. | |
| 318965688 | proteasome | a cellular organelle that degrades proteins marked with ubiquitin |
