How do you find out if something is alive or dead?

In order for something to be classified as living, it must grow and develop, use energy, reproduce, be made of cells, respond to its environment, and adapt. While many things meet one or more of these criteria, a living thing must meet all of the criteria.

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.