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Saturday 24 February 2018


Definition: Structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized.

Material structures include man-made objects such as buildings and machines and natural objects such as biological organisms, minerals and chemicals. Abstract structures include data structures in computer science and musical form.

Types of structure include a hierarchy (a cascade of one-to-many relationships), a network featuring many-to-many links, or a lattice featuring connections between components that are neighbors in space.


Living structures are biological strutures or biostructures.

In biology, structures exist at all levels of organization, ranging hierarchically from the atomic and molecular to the cell , tissue , organ , organism , population and ecosystem level.

Usually, a higher-level structure is composed of multiple copies of a lower-level structure.

The structural biology studies the biomolecular structure of macromolecules, particularly proteins and nucleic acids.

The function of these molecules is determined by their shape as well as their composition, and their structure has multiple levels.

The protein structure has a four-level hierarchy. The primary structure is the sequence of amino acids that make it up. It has a peptide backbone made up of a repeated sequence of a nitrogen and two carbon atoms. The secondary structure consists of repeated patterns determined by hydrogen bonding. The two basic types are the α-helix and the β-pleated sheet. The tertiary structure is a back and forth bending of the polypeptide chain, and the quaternary structure is the way that tertiary units come together and interact.

The nucleic acids , the lipids and the carbohydrates also have biological structures and form the biological organization.


The study of structures is morphology.

Structures can be studied by morphology ( scopy of the scope ) and can be :
- visible at naked eye : macroscopy : macroscopical structures
- non visicble at naked eye : microscopy : microscopical structures

These structures can be abnormal
- macroscopical anomalies
- microscopical anomalies

See also

- structuralism