DNA supercoiling means under or over winding of the DNA strand and basically is to become more condensed and more organized. Supercoiling is very important as it compacts the genetic code and as if that was not enough supercoiling also regulates and oversees the access the the genetic code.
Secondary structures are dependent upon hydrogen bonding. The two main types of secondary structure are the a-helix and the B-sheet. The a-helix is a right-handed coiled strand.
Algae and nitrogen-fixing bacteria are photosynthetic organisms.