The structure of DNA is called a double helix because DNA is made up of two strands of nucleotides wound together in a spiral.
DNA has two strands that run opposite of each other and twist together much like a twisted ladder. Each backbone of the ladder is made up of alternating groups of sugar and phosphate groups.
As ribosomes make their proteins, they may attach to the rough ER and insert the protein into the interior of the ER. The ER then begins folding the new proteins and transports them to areas in which chemical processing takes place
