Question

Gene Expression—Flow of Information from Gene to Protein Tour. Which tRNA anticodon sequence is the correct match to the mRNA codon listed below? Note: codon-anticodon base-pairing is antiparallel. 5'-CGA-3'

A) 5'-UCG-3'
B) 5'-GCU-3'
C) 5'-CGU-3'
D) 5'-AGC-3'

Answer 1

The correct tRNA anticodon that pairs with the mRNA codon 5'-CGA-3' is 5'-UGC-3', which is option B) 5'-GCU-3', as tRNA anticodons are complementary and antiparallel to mRNA codons.

Step-by-step explanation:

In the process of translation, mRNA codons are paired with tRNA anticodons to translate the language of RNA into the language of proteins. Each tRNA molecule must have an anticodon that is complementary to the mRNA codon for proper attachment and addition of the correct amino acid to the growing polypeptide chain.

The mRNA codon given is 5'-CGA-3'. To find the correct tRNA anticodon, we need the sequence that is complementary and antiparallel to this codon. Remember, A pairs with U and G pairs with C in RNA sequences. Therefore, the correct tRNA anticodon is 3'-GCU-5' which, when written in the conventional 5' to 3' orientation, becomes 5'-UGC-3'. This means that the correct answer is option B) 5'-GCU-3'.