DNA/ RNA Flashcards
What are the 3 characteristics of RNA
- Single stranded
- Uracil not Thymine
- Ribose not 2-Deoxyribose
What are the 3 forms of RNA?
- Messenger, mRNA (ss)
- Ribosomal, rRNA (ds)
- Transfer, tRNA (ds)
What is the unit ‘S’?
Svedberg units: sedimentation rates of RNA types
Which type of RNA is heterologous?
mRNA: different lengths - no single size dominants
Define transcription:
RNA polymerase synthesises a complementary copy of one of the DNA strands (exact copy)
Define translation
Process of reading mRNA using tRNA w/ complementary anticodons that attach amino acids to chain
What is on the 5’ end of deoxyribose?
free phosphate groups
What is on the 3’ end of deoxyribose?
free hydroxyl groups
What are the 5 elements of a gene unit? (prokaryote)
- promotor
- ribosome binding site
- leader/ signal sequence (only exports)
- open reading frame
- terminator
Which end of a gene is the downstream end?
3’
What are chaotrophic agents?
They disrupt hydrogen bonds in water/ between
- increases the entropy of a system
- can denature DNA/RNA
What are common chaotrophic agents for RNA?
- Formamide
- Formaldehyde
- Guanidinium Isothiocynate
- Phenol
When is urea used as a CA?
in special polyacrylamide DNA sequencing gels
What are issues with isolating RNA?
- SS: easily fragmented by ribonuclease enzymatic digestion (less yield of full length heterologous RNA)
- Need to separate from other macromolecules p23.