So early spring-driven clocks slowed down over their running period as the mainspring unwound. Some natural silk structures have been used without being unwound or spun. The DNA double helix is unwound by the helicase activity of the enzyme. Her singing (unwound) like a spool of satin. The Betamax Bandit consists primarily of unwound Betamax video tape. The tow can be conveniently unwound from the reel for use. As it unwound, it restarted the motor in the correct direction. In the "open complex" the promoter DNA is partly unwound and single-stranded. He unwound several folds of old cloth, and held up a small shirt of mail. This drum could be towed across the channel and the pipe unwound onto the seabed. This condenses on the cold polymer film, which is unwound near the metal vapour source. As the DNA is unwound the twist number decreases. As the cable unwound due to the force of gravity, the clock hands turned. Because DNA must be unwound for DNA/RNA polymerase action, supercoils will result. This unwound section is known as the transcription bubble.