Best Times to Go to Florence, Italy. Avoid summers if you can, it's hot and packed with sweating tourists in July and August. That said, there's hardly a time you won't encounter tourists in Florence. If you must go in summer, make hotel reservations early.
Helical. Helical (adjective) is having a spiral form of many rounds. Helical can be a hairstyle curl, loop fold of a ribbon that serves as pony and a repeated dialogue of an actor that gives twist to the audience.
DNA helicase is the enzyme that unwinds the DNA double helix by breaking the hydrogen bonds down the center of the strand. It begins at a site called the origin of replication, and it creates a replication fork by separating the two sides of the parental DNA. This 'unzipping' of the molecules will expose the nitrogenous bases of the nucleic acid chain so that new nucleotides can be added to create the daughter strand.