9.3 - 9.4 Flashcards
Transfer RNA nucleotides
74-95 nucleotides (short)
Transfer RNA
small RNA adapter moelcule that, through complementary base pairing with codons in mRNA, places a specific amino acid at the correct position in a growing polypeptide chain at the ribosome
tRNA secondary structur
cloverleaf
tRNA tertiary structure
looks compact letter L
anticodon
codon in tRNA molecules that recognize codon on the mRNA by complementary base pairing and wobble
Amino acid is attached on
3’ end of tRNA
Aminoacyl-tRNA synthetases
enzymes that catalyze the attachment of tRNAs to the amino acids that corresponds to tRNA’s anticodon, forming charged tRNAs
Only molecules that read both nucleic acid and protein language
Aminoacyl-tRNA synthetases
One Aminoacyl-tRNA synthetases exists for
each of the 20 common amino aicds
Charged tRNA
a tRNA molecule to which the corresponding amino acid has been attached y an aminoacyl-tRNA synthetase (uses ATP)
Bond between the amino acid and tRNA contains substantial energy that is later used to form
peptide bonds
Amino acid attached to tRNA treated with nickel hydride
changes amino acid
Treatment with nickel hydride on anticodon
leaves anticodon unchanged
Specific interaction between a tRNA’s anticodon and mRNA’s codon determines
which amino acid is added to growing polypeptide chain
Wobble
the ability of the 5’-most base of an anticodon to pair with more than one type of base at the 3’ ends of codons