Question

Make sure to show where 5' and 3' ends are

5' ATG AAG GCU CGU 3'

1. What is the sequence of the template strand of DNA

2. What is the sequence of the non-template strand of DNA.

3. What is the amino acid sequence

Answer 1

1. In a DNA molecule, the 3' to 5' strand is called the template strand or the non-coding strand. During transcription, this strand is used as the template to synthesize the mRNA.

The sequence given in the question have uracil (U) nitrogen base. Thymine is present in DNA instead of uracil. Uracil is present in RNA molecules only. Hence, the sequence of the template strand of the DNA will be -

3'- ATG AAG GCT CGT -5'

2. In a DNA molecule, the 5' to 3' strand is called the coding strand or non-template strand. During transcription, this strand is not used as a template for synthesizing mRNA. That's why the 5' to 3' strand is called the non-template strand. The sequence of this strand corresponds with the sequence of the mRNA produced through transcription.

The sequence of the non-template strand of the DNA will be -

5'- TAC TTC CGA GCA -3'

3. The amino acids will be produced through the translation of the mRNA. So, to determine the amino acid sequence, we need to know the sequence of the mRNA. The sequence of the mRNA is - 5'- AUG AAG GCU CGU -3'.

The codon triplet AUG codes for methionine (Met), AAG codes for lysine (Lys), GCU codes for alanine (Ala), CGU codes for arginine (Arg)

Hence the amino sequence will be -

5'- Met - Lys - Ala - Arg - 3'