Q28-7P - Organic Chemistry (Mcmurry)

Question

List codon sequences for the following amino acids:

(a) Ala

(b) Phe 

(c) Leu 

(d) Tyr

Step-by-Step Solution

Answer

(a) The codons of the sequences for the amino acids are

$$\begin{gathered} (5\text{'})-GCU-(3\text{'}) \\ (5\text{'})-GCC-(3\text{'}) \\ (5\text{'})-GCA-(3\text{'}) \\ (5\text{'})-GCG-(3\text{'}) \end{gathered}$$

(b) The codons of the sequences for the amino acids are:

$$\begin{gathered} (5\text{'})-UUU-(3\text{'}) \\ (5\text{'})-UUC-(3\text{'}) \end{gathered}$$

 

(c) The codons of the sequences for the amino acids are

 

$$\begin{gathered} (5\text{'})-UUA-(3\text{'}) \\ (5\text{'})-UUG-(3\text{'}) \\ (5\text{'})-CUU-(3\text{'}) \\ (5\text{'})-CUC-(3\text{'}) \\ (5\text{'})-CUA-(3\text{'}) \\ (5\text{'})-CUG-(3\text{'}) \end{gathered}$$

 

(d) The codons of the sequences for the amino acids are:

$$\begin{gathered} (5\text{'})-UAU-(3\text{'}) \\ (5\text{'})-UAC-(3\text{'}) \end{gathered}$$

Concept

An amino acid is coded by three consecutive nucleotides in a DNA or RNA molecule. Codes signal the start or end of translation.

(a) Codon sequence of Ala

G is the first base and C is the second and U, C, A, and G are the third bases. There are four codon sequences. The codon sequences are,

$$\begin{gathered} (5\text{'})-GCU-(3\text{'}) \\ (5\text{'})-GCC-(3\text{'}) \\ (5\text{'})-GCA-(3\text{'}) \\ (5\text{'})-GCG-(3\text{'}) \end{gathered}$$

(b) Codon sequence of Phe

U is the first base and U is the second and U and C are the third bases. There are two codon sequences. The codon sequences are,

$$\begin{gathered} (5\text{'})-UUU-(3\text{'}) \\ (5\text{'})-UUC-(3\text{'}) \end{gathered}$$

(c) Codon sequence of Leu

U is the first base and U is the second and A & G are the third bases. There are two codon sequences. The first and second bases are C and U and the third bases are U, C, A, and G. There are 4 codon sequences and 7 codon sequences in total.

The codon sequences are,

$$\begin{gathered} (5\text{'})-UUA-(3\text{'}) \\ (5\text{'})-UUG-(3\text{'}) \\ (5\text{'})-CUU-(3\text{'}) \\ (5\text{'})-CUC-(3\text{'}) \\ (5\text{'})-CUA-(3\text{'}) \\ (5\text{'})-CUG-(3\text{'}) \end{gathered}$$

(d) Codon sequence of Tyr

U is the first base and A is the second and U and C are the third bases. There are two codon sequences. The codon sequences are,

$$\begin{gathered} (5\text{'})-UAU-(3\text{'}) \\ (5\text{'})-UAC-(3\text{'}) \end{gathered}$$