Final answer:
DNA must supercoil every 10 base pairs (bp) to manage tension and maintain its structure for replication and transcription, with the aid of enzymes like DNA gyrase (topoisomerase).
Step-by-step explanation:
DNA must supercoil once every 10 base pairs (bp) to prevent over-twisting and strain on the double helix structure. This supercoiling is critical for maintaining the stability and integrity of the DNA molecule. The double helix of DNA consists of two antiparallel strands twisted around each other, with each full turn of the helix comprising approximately 10.5 base pairs. This spatial arrangement results in consistent major and minor grooves, which are crucial for protein binding. Proteins such as DNA gyrase (or topoisomerase) help in managing DNA supercoiling by introducing negative supercoils to alleviate the tension that builds up ahead of the replication fork during DNA replication. This process is vital because it helps prevent the DNA double helix from becoming too tightly coiled, which would otherwise impede essential biological processes such as replication and transcription.