Question

This is a a question from my Intro to Molecular Biology class: "What should the reading frame be on? "

I am unsure if it is a specific structure or referring to the direction of the reading frame

1. What should the reading frame be on?

Answer 1

In molecular biology, a reading frame is a pattern to divide the nucleotide sequence of DNA and RNA in to a continuous and non overlapping triplet codon. No termination codon is present in reading frame. In the given question, it is asking about the direction of the reading frame. Its direction or it is read from  5′-end.

Every nucleic acid with single strand has two ends

• 5′-end or phosphoryl end
• 3′-end or hydroxyl end

Example of reading frame --

5′ AGA-TGA-CAC-CGC-AAG-CCT-TAT-ATT-AGC 3′

5′ A-GAT-GAC-ACC-GCA-AGC-CTT-ATA-TTA-GC 3′

5′ AG-ATG-ACA-CCG-CAA-GCC-TTA-TAT-TAG-C 3′

In this 5'→3' direction, there are three reading frames, starts with diffrent nucleotide in codon. Nucleic acid with double strand have three more redaing frames.The two strand are anti parallel to each other. The 5'→3' direction oF the second strand corresponds to the 3'→5' direction of first strand