Flashcards in Overview of translation, tRNA and codon-anticodon interaction Deck (24):
Using an arrow diagram, what happens when genes are expressed?
DNA -> mRNA -> Protein
Nucleus --- || --- cytosol
What is the process to get mRNA from DNA?
What is the process to get protein from mRNA?
How are genes in bacteria arranged?
Closely-packed (with only very short gaps between them) and are commonly co-transcribed to generate polycistronic mRNAs
What is meant by 'cistron'?
'mRNA coding sequence or 'open reading frame' (ORF)
How are genes in higher eukaryotes such as animals and plants arranged?
'Miles apart' and cannot possibly be co-transcribed. Hence, eukaryotic mRNAs are monocistronic
How are genes in lower eukaryotes such as yeast arranged?
Almost as close-packed as in bacteria but they are not co-transcribed
How many translation start sites are in prokaryotic mRNA (polycistronic)?
How many translation start sites are in eukaryotic mRNA (monocistronic)?
A single site
In all cell types, mRNAs are translated concurrently by..
Multiple ribosomes in structures termed 'polyribosomes'
In eukaryotes, where are mRNAs translated?
In the cytosol
tRNA contains 'odd' bases and nucleosides such as what?
Dihydrouracil (UH2 or DHU)
What type of structure is a 'cloverleaf'?
What type of structure is the co-axial stacking of mini-helices?
Posttransciptional chemical modification of eukaryotic rRNA mainly involves..
Ribose methylation and pseudouridylation
In contrast, bacterial rRNA is much less heavily modified
Chemical modification of tRNA principally involves..
Base methylation including generation of extravagant derivatives ('hyper modification')
Describe the interaction between a codon and an anticodon
A triplet base pair interaction via antiparallel strands
What happens due to 'Wobble Pairing'?
tRNAs recognise multiple mRNA codons (1, 2 or 3)
mRNA codons can be recognised by multiple tRNAs
There is one aaRS per what?
What does aaRS stand for?
What are aaRS named specifically after?
The cognate amino acid
e.g. PheRS, AlaRS, LysRS
Each E recognises what>
>= 1 x tRNA
aaRS has a crucial role in what?
Fidelity of translation