So what do we mean by turn? Well, let's begin on this point on our DNA molecule, on this strand. And when the strand basically makes a 360 degree turn, that is what we mean by single turn. And in that 360 degree turn, there are ten bases. And that means every time we go from one base to another, there's an angle change in 36 degrees, because 36 divided by ten gives us 36 degrees. So every single time we go from, let's say, this base pair down to this base pair, the DNA turns by 36 degrees.