Question

Imagine that Martians have nucleotides where both the 3' and 5' Carbons had Hydroxyl groups attached and formed ether bonds to join nucleic acids. Would their DNA be considered Antiparallel?

Answer 1

If Martian DNA's nucleotides are connected by ether bonds in a double-stranded structure where one strand runs 5' to 3' and the opposite strand runs 3' to 5', it would still be considered antiparallel. The essential feature is the orientation of the strands, not the type of chemical bond linking the nucleotides.

Step-by-step explanation:

The concept of DNA being antiparallel refers to two strands of nucleotides running in opposite directions relative to their 5' and 3' ends. In the traditional structure of DNA, the 5' end of one strand faces the 3' end of the complementary strand, with the sugar-phosphate backbones forming the outer boundaries of the molecule and the nitrogenous bases pairing in the interior.

If Martian DNA has nucleotides that connect via ether bonds rather than the phosphodiester bonds found in earthly DNA, the arrangement could still be antiparallel if one strand runs 5' to 3' and the other runs in the opposite direction, from 3' to 5'. The critical aspect is the relative orientation of the strands, not the specific type of chemical bond that connects the nucleotides. Therefore, if Martian DNA's nucleic acids are arranged such that opposite strands are oriented in reverse directions with respect to the carbon numbering, it would indeed be considered antiparallel.