Final answer:
The strands that make up DNA are antiparallel, meaning the 5' to 3' direction of one strand is opposite to that of the other strand. This arrangement is vital for the biological functions of DNA, such as replication and repair.
Step-by-step explanation:
The correct definition of antiparallel when it comes to DNA is that the 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand, DNA strands are composed of a sugar-phosphate backbone and nitrogenous bases that connect the two strands. Each DNA strand has a directionality, with one end labeled as the 5' end and the other as the 3' end. The two strands are complementary with adenine pairing with thymine and cytosine pairing with guanine, creating the double helix structure.
The double-helix structure, the two strands are not parallel but rather run in opposite directions, meaning that while one strand runs in the 5' to 3' direction, the other runs 3' to 5'. This antiparallel alignment is crucial for the functions of DNA, including replication and repair mechanisms. It ensures that the enzymes involved in these processes can recognize and interact with DNA in the correct orientation. Since each enzyme has a specific directionality for function, the antiparallel strands enable the enzymes to work on both strands simultaneously during DNA replication. Plagiarism free content is ensured as this explanation has been formulated based on the provided reference material.