1. Structure: DNA has a unique double helix structure. This structure is formed by two long strands of nucleotides that wind around each other like a twisted ladder. The sides of the ladder are made up of alternating sugar (deoxyribose) and phosphate groups, while the rungs of the ladder are made up of nitrogenous bases (adenine, guanine, cytosine, and thymine).

2. Sequence: The specific order of the four nitrogenous bases (adenine, guanine, cytosine, and thymine) along the DNA molecule is called the genetic code. This sequence contains the instructions for building and maintaining an organism. Each gene within the DNA molecule contains a specific sequence of bases that codes for a particular protein or RNA molecule.

These two properties are intertwined. The specific sequence of bases within the DNA molecule is crucial for the structure of the double helix, and the double helix structure helps protect the sequence from damage.