# Structural Biochemistry/Biological Bases
## Background

The foundations of biochemistry can be broken down into cellular foundation, chemical foundation, physical foundation, genetic foundation, and evolutionary foundation. The foundation of biochemistry can be described as a study relating the structure to the properties of biological macromolecules, as well as understand the function.
Biological foundations can be described as the study of the structures, the properties, and the reactions of biological macromolecules, such as proteins and carbohydrates on a cellular, chemical or physical level. By understanding the structure of these macromolecules, often the properties will be more apparent and the function can be understood. It can also be described in terms of genetics, such as the basis of genetics as the study of the structure of DNA,RNA, and amino acids sequences and how their structure helps to define and give understanding to how they work.
Biological foundations can also be described on an evolutionary basis such as the three domains of life (Archaea,Bacteria, and Eukarya).
The biological basis of structural biochemistry focuses mainly around evolutionary, genetic, and cellular foundations.

## Distinguishing Properties of Living Organisms

Living organisms are complex and organized systems composed of many cells. These cells may be highly specialized for different functions. In turn, these cells are composed of sub cellular structures which are then composed of macromolecules. These macromolecules are the cellular machinery that allow a cell to complete its tasks.

### Anatomical Structure Complements Function

Each part of an organism serves a purpose. Each organelle is structured in a way so that it may compensate changes in its environment and allow for many processes to occur. In the microscopic world, molecules are structured so they can serve functional tasks, such as eenzymes, hormones, or proteins. In Biology, it is important to relate the structures and organizations to the functional roles they serve in the organism.

### Systems and Energy Transformation

In order to maintain, build, and live, organisms must extract and transform energy from their environments. This energy, which may be extracted from the sun or from food, allows an organism to do mechanical, chemical, osmotic and electrical work to maintain its highly organized structures. In other words, energy and material are used to maintain stability of the organism, a process known as homeostasis.

### Self Replication

Throughout time, organisms reproduce to give nearly identical copies. The most complex molecules are replicated with great accuracy. The genetic material which is responsible for this is deoxyribonucleic acid, or DNA. This accuracy still has some probability of error and gives rise to evolutionary change. Because of environments which may harm the organism, organisms adapt and may change their structure to accommodate survival.

### Capacity for evolutionary change

An organism has to have a history of evolutionary change. An evolution tree displays the pathways where organisms may have gone through divergent of convergent evolution.

### Respond to stimuli

An organism has to be able to perceive the environment through their senses. They need to be able to respond and adapt to the changes in the environment.