mRNA Translation 2 Flashcards
What are codons?
triplets of DNA nucleotide on the mRNA that code for an amino acod
TRUE or FALSE
Each codon codes for one particular amino acid
FALSE
Différents codons peuvent coder un même acide aminé, avec l’exception de la Méthionine (Met, ou M) et le Tryptophane (Trp, ou W)
What is the codon of initiation? What is the amini acid associated with it?
Le premier codon AUG (Méthionine) sur un cadre de lecture signale Initiation
What are the stop codons?What is the amini acid associated with it?
Il y a également 3 codons (UAA, UAG, UGA) qui signalent STOP
No amino acid associated with it
True or Flase,
ALL SPECIES IN OUR PLANET utilisent le même code génétique
True
True or Flase,
UTR is only found in 3’ (poly AAAAA)
FALSE,
Also present in the Coiffe (5’)
What is the ORF?
Open Reading Frame
Cadre de lecture ouvert
AUG -> stop codon (UAG, UAA, UGA)
Explain Silent mutation: ?
Change of say GGC to GGA but they both code for Glycine so no difference
Explain Faux-Sense mutation
CGT to CAU → from Arg to His
Common bad nucleotide but only changes one amino acid so not so bad
Explain Non-stop (nonsense) mutation?
Change of a codon for a stop codon
If late, maybe won’t do much, if early the protein won’t be complete and thus degraded
Explain Continuation mutation?
Stop codon transformed to another codon → longer protein
Not a big deal because there are so many stop codons you might put a few more amino acids and then stop
What is the worst kind of mutation?
Deletions or insertions. This leads to litereally every codon to be missread for another (pushed by one)
What is the complex that reads and translates mRNA?
Ribosomes
How do Ribosomes translate mRNA?
Ribosomes use ARNt (tRNA; RNA de transfer)
Forms a tige boucle that allows the ribosome to recognize the tRNA and use it to read the mRNA
The anticodon of the tRNA can bind to the mRNA
tRNA is also attached to a amino acid that can be used to form the polypeptide chain
True or False,
tRNA does not recognize the STOP codons
TRUE
