L17 Evolutionary Genetics: DNA or proteins first? Flashcards
LUCA
Last Universal Common Ancestor
Unlike DNA, RNA can act as both an information store and…
A biocatalyst
Differences between RNA and DNA, RNA has (3)…
- Uracil (U) instead of Thymine (T)
- An additional -OH (less stable)
- A single strand (more complex structural possibilities)
Ribozymes are RNA…
Enzymes
The spliceosome involved in mRNA splicing contains a…
Ribozyme
RNA can bind to small molecules and change their conformation, acting as…
Riboswitches
Tetrahymena is a…
Unicellular, ciliate protozoan
Tetrahymena rRNA contains an extra piece, which contains…
A self-splicing intron
SELEX
Systemic Evolution of Ligands by Exponential Enrichment
SELEX is used to identify…
Specific RNAs
SELEX process (7)…
1) Initial library
2) Pool generation
3) Insertion of target and subsequent binding
4) Wash (removes unbound RNA)
5) Elution (removal of RNA from the mixture)
6) Amplification
7) Evaluation (binding assay, diversity assay, sequencing)
SELEX process (7)…
1) Initial library
2) Pool generation
3) Insertion of target and subsequent binding
4) Wash (removes unbound RNA)
5) Elution (removal of RNA from the mixture)
6) Amplification
7) Evaluation (binding assay, diversity assay, sequencing)
Aptamers…
are molecules (peptides or nucleic acids) that bind to specific targets
SELEX uses…
RNA aptamers
The RNA world hypothesis is plausible as…
- RNA can store information and catalyse reactions
- There is plausible continuity with current organisms
- It is simple
