What is the structural unit of compact bone?

Osteon is the structural unit of compact bone.

Explanation:

Compact bone is present around the medullary cavity and forms the external layer of the bones. Compact bone is made up of structural units called osteon.

Osteon is also known as haversian sysytem. Osteons contain mineral matrix and connencted by canaliculi. Osteons helps in the transportation of blood. Osteonic canal is known as haversian canal and aligned parallel with the long bones. Osteon contains lamellae that forms the layer of the compact matrix. Osteon prevents the bone from fracture and resist the bending of bones.

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.

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.