1. Explain the general mechanisms and controls of transcription and RNA processing.
2. Define the concept, "central dogma" of molecular biology.
3. Describe how dynamic reorganization of chromatin structure is related to regulation of
gene expression.
4. Define transcription as conversion of the DNA genetic code into an RNA code.
5. Describe the functions of regulatory elements; promoters, enhancers, silencers, a.k.a.
"cis-elements") in the production of RNA.
6. Describe the function of trans-elements or transcription factor proteins, that interact with
DNA regulatory elements.
7. Explain how reversible modification of some transcription factors (e.g. phosphorylation)
can regulate of gene expression / trsaanscription (DNA RNA).
8. Describe the events involved with initiation, elongation and termination of transcription.
9. List some functional differences between prokaryotic and eukaryotic mRNAs
(polycistronic vs monocistronic, RNA processing or splicing and modifications).
10. Describe introns and exons in the splicing of eukaryotic mRNAs, and th
| 856204823 | mRNA | message RNA - gene coding sequences | |
| 856204824 | rRNA | ribosomal RNA - scaffolding and action centers for ribosomes | |
| 856204825 | tRNA | transfer RNA - adaptor molecule, decodes genetic code on mRNA | |
| 856204826 | miRNA | micro RNA - gene expression regulators | |
| 856204827 | snRNA | small nuclear RNA - RNA processing molecules - splicosomes | |
| 856204828 | Transcription: | Transcription is the conversion of specific regions of DNA into various species of RNA. | |
| 856204829 | The Central Dogma of molecular biology: | DNA (transcription) RNA (translation) protein RNA (reverse transcription) DNA DNA (replication) 2X DNA | |
| 856204830 | Chromatin | occurs in both Prokaryotes and Eukaryotes but it is much more complicated in Eukaryotic chromosomes. Chromatin must be organized into an appropriate structure in order for gene expression (or replication) to occur. | |
| 856204831 | heterochromatin) | here are DNA storage structures that sequester away gene sequences preventing their expression | |
| 856204832 | euchromatin | here are more open structures allowing the protein transcription factors access to the specific DNA sequences | |
| 856204833 | promoters and enhancers | Once these protein factors bind to their target DNA regulatory sequence elements genes expression (transcription) can begin. | |
| 856204834 | silencers | Other transcription factors block transcription. These work by binding DNA regulatory elements (silencers) that inhibit gene expression. | |
| 856204835 | Cis-elements | specific DNA sequences (promoters and enhancers or silencers). | |
| 856204836 | Trans-elements | iffusible protein factors (transcription factors) that bind to specific DNA sequences (cis-elements) or structures affecting gene expression / transcription. | |
| 856204837 | A key consideration for gene expression (transcription) involves the competition of chromatin | packing factors with transcription factors for various specific regulatory DNA sequences. This competition can be regulated by environmental factors, allowing environmental factors to control aspects of gene expression (adaptation). | |
| 856204838 | nucleosome | is the fundamental protein complex for packaging eukaryotic DNA. Several factors affect the dynamic functions of a nucleosome in its reversible binding, packaging and organization of DNA. | |
| 856204839 | Histone Acetyl Transferase (HAT) | is an enzyme that attaches acetate groups to lysine residues on nucleosomes opening/loosening their interaction with DNA by blocking electrostatic interactions with the phosphoribosyl backbone. Moving the nucleosomes around (remodeling) can uncover specific DNA sequences allowing competition for binding with transcription factors (trans-elements) promoting gene expression. | |
| 856204840 | Histone Deacetylase (HDAC) | removed from the nucleosome allowing them to condense back together again with a higher affinity for DNA, occluding the cis-elements (promoter sequences), preventing transcription factor binding and leading to gene silencing. Histone Deacetylase (HDAC) is an example of this type of reversible enzyme system. Stabilizing tight chromatin structures with inhibitory transcription factors binding to specific DNA silencer elements is another method of blocking gene expression. |
