The only structure of the inner ear concerned with hearing is the:

Ear is responsible for balancing and hearing. There are three components of the ear: Outer ear, middle ear and inner ear.

The inner is made up of bony tubes (labyrinth) filled with fluids encased within the temporal of the skull. The bony labyrinth is made up of three sections namely:

 Cochlea: This is responsible for hearing.

Semicircular: Their function associated with balance,

Vestibule: which connects the two and contains two more balance? 

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.