Question

Question: From what DNA sequences were each of the mRNA codons in Problem 28-26 transcribed?

Short answer

In solution (a), the antisense DNA strand transcribed is$3^{\text{'}}-\text{T}-\text{T}-\text{A}-5^{\text{'}}$

In solution (b), the antisense DNA strand transcribed is$3^{\text{'}}-\text{C}-\text{T}-\text{C}-5^{\text{'}}$

In solution (c), the antisense DNA strand transcribed is${\text{3}}^{\text{'}}-\text{A}-\text{G}-\text{G}-5^{\text{'}}$

In solution (d), the antisense DNA strand transcribed is$3^{\text{'}}-\text{G}-\text{T}-\text{A}-5^{\text{'}}$

Step-by-step solution

Introduction

The antisense strand of DNA is used to produce mRNA molecules. This sequence will have thymine instead of uracil and is complementary to the mRNA.

Explanation for (a)

The mRNA moleculesare made by transcribing the antisense strand of the DNA molecules.

The mRNA strand is,

$5^{\text{'}}-\text{A}-\text{A}-\text{U}-3^{\text{'}}$

The complementary antisense DNA strand is,

role="math" localid="1663325949323" ${\mathbf{3}}^{\mathbf{\text{'}}}\mathbf{-}\mathbf{\text{T}}\mathbf{-}\mathbf{\text{T}}\mathbf{-}\mathbf{\text{A}}\mathbf{-}{\mathbf{5}}^{\mathbf{\text{'}}}$

Explanation for (b)

The mRNA moleculesare made by transcribing the antisense strand of the DNA molecules.

The mRNA strand is,

$5^{\text{'}}-\text{G}-\text{A}-\text{G}-3^{\text{'}}$

The complementary antisense DNA strand is,

${\mathbf{\text{3}}}^{\mathbf{\text{'}}}\mathbf{-}{\mathbf{\text{C-T-C-5}}}^{\text{'}}$

Explanation for (c).

The mRNA moleculesare made by transcribing the antisense strand of the DNA molecules.

The mRNA strand is,

${\mathbf{\text{5}}}^{\mathbf{\text{'}}}\mathbf{-}\mathbf{\text{U}}\mathbf{-}\mathbf{\text{C-C}}\mathbf{-}{\mathbf{3}}^{\text{'}}$

The complementary antisense DNA strand is,

${\mathbf{3}}^{\mathbf{\text{'}}}\mathbf{\text{-A-G-G-}}{\mathbf{5}}^{\mathbf{\text{'}}}$

Explanation for (d)

The mRNA moleculesare made by transcribing the antisense strand of the DNA molecules.

The mRNA strand is,

$5^{\text{'}}\text{-C-A-U-}{3}^{\text{'}}$

The complementary antisense DNA strand is,

${\mathbf{3}}^{\mathbf{\text{'}}}\mathbf{\text{-G-T-A-}}{\mathbf{5}}^{\mathbf{\text{'}}}$