Question

Compare the structural formulas of the aromatic amino acids phenylalanine and tyrosine. Also compare the codons for these two amino acids.

Short answer

Answer: The main difference between the structural formulas of phenylalanine and tyrosine lies in their side chains. Phenylalanine has a -CH2- phenyl group attached, while tyrosine has a -CH2- para-hydroxyphenyl group. The hydroxyl group (OH) in tyrosine contributes to the extra oxygen atom in its molecular formula. Regarding their codons, both amino acids share Uracil (U) in the first base position. However, phenylalanine has Uracil (U) in the second position, while tyrosine has Adenine (A); in the third position, both can have either Uracil (U) or Cytosine (C).

Step-by-step solution

Identify the Structural Formulas of Phenylalanine and Tyrosine

We can start by identifying the structural formulas for both phenylalanine and tyrosine. Phenylalanine has the structural formula as follows: \[\text{C}_9\text{H}_{11}\text{NO}_2\] and tyrosine has the structural formula: \[\text{C}_9\text{H}_{11}\text{NO}_3\]. Remember that both of these amino acids are aromatic, which means they contain a ring structure.

Compare the Structural Formulas between Phenylalanine and Tyrosine

We can see from the structural formulas that both phenylalanine and tyrosine share the same aromatic ring structure derived from benzene. The difference between their structures lies in the side chains. Phenylalanine has a -CH2- phenyl group attached, while tyrosine has a -CH2- para-hydroxyphenyl group. The hydroxyl group (OH) in tyrosine is the main difference between the two amino acids' structures. This hydroxyl group is what contributes to the extra oxygen atom in tyrosine's molecular formula.

Identify the Codons for Phenylalanine and Tyrosine

We need to identify the codons for phenylalanine and tyrosine to compare them further. In mRNA, phenylalanine is coded by the codons UUU and UUC, while tyrosine is coded by the codons UAU and UAC.

Compare the Codons for Phenylalanine and Tyrosine

Comparing the codons for both phenylalanine and tyrosine, we can see some similarities and differences. Both amino acids have two codons each, and they share the same Uracil (U) in the first position. The difference lies in the second and third base positions. Phenylalanine has Uracil (U) in the second position, while Tyrosine has Adenine (A) in the second position. In the third position, Phenylalanine has either Uracil (U) or Cytosine (C), and Tyrosine has either Uracil (U) or Cytosine (C) as well.