In studies using repeating copolymers, AC . . . incorporates threonine and histidine, and CAACAA . . . incorporates glutamine, asparagine, and threonine. What triplet code can definitely be assigned to threonine?

Verified step by step guidance

1. Identify the repeating sequences and the amino acids they incorporate: AC... incorporates threonine and histidine, while CAACAA... incorporates glutamine, asparagine, and threonine.
2. Determine the possible codons from the repeating sequences. For AC..., the repeating units are 'A' and 'C', so possible triplets include ACA, CAC, and so on. For CAACAA..., the repeating units are 'C', 'A', and 'A', so possible triplets include CAA, AAC, ACA, etc.
3. List the amino acids associated with each possible triplet from the sequences. For example, ACA is known to code for threonine, CAC for histidine, CAA for glutamine, and AAC for asparagine.
4. Compare the amino acids incorporated by each triplet to the amino acids observed in the repeating copolymers. The triplet that appears in both sequences and corresponds to threonine can be assigned definitively to threonine.
5. Conclude which triplet code corresponds to threonine by identifying the triplet common to both sequences that codes for threonine, based on the known genetic code.

Key Concepts

Genetic Code and Codon Assignment

The genetic code consists of triplet nucleotide sequences called codons, each specifying a particular amino acid. Understanding which codons correspond to which amino acids is essential for decoding protein sequences from nucleotide sequences.

Repeating Copolymers in Genetic Code Studies

Repeating copolymers are synthetic nucleotide sequences used to identify codon assignments by observing which amino acids are incorporated during translation. By analyzing the amino acids produced from known repeating sequences, researchers can deduce specific codon-amino acid relationships.

Amino Acid Incorporation and Codon Overlap

When multiple amino acids are incorporated from overlapping codons in repeating sequences, comparing which amino acids appear in different sequences helps isolate the codon for a specific amino acid. This comparative approach allows definitive assignment of codons to amino acids like threonine.