Final answer:
The dipeptide that will form from the mRNA sequence 5' CCG-ACG 3' is proline-threonine, as CCG codes for proline and ACG codes for threonine.
Step-by-step explanation:
To determine the dipeptide that will form from the mRNA sequence 5' CCG-ACG 3', we need to translate this sequence into amino acids using the genetic code. The codon CCG codes for the amino acid proline and the codon ACG codes for the amino acid threonine. Therefore, when a ribosome reads this mRNA sequence and matches it with the charged transfer RNA (tRNA) molecules, a dipeptide consisting of proline and threonine will form.
Given the options provided, the correct answer is A. Proline-threonine.
The translation process involves the ribosome initiating synthesis at the N-terminal amino acid and proceeding in the direction of the 5' to 3' end of the mRNA. Peptide bond formation is catalyzed by the enzyme peptidyl transferase, resulting in the elongation of the polypeptide chain with the sequential addition of amino acids.