Biological objective functions

The chemical composition of biological objects is extremely complex. They contain the macromolecules of proteins, lipids, and many other substances in addition to low-molecular-weight organic and inorganic compounds. Different external effects can produce both quantitative and qualitative composition changes some substances disappear and/or others appear. Some substances that are essential for the functioning of the cells or of the entire organism are present in very small concentrations, lO Mand less. 

The term evolutionary algorithm (EA) refers to a class of population based metaheuristic (probabilistic) optimization algorithms which imitate the Darwinian evolution ( survival ofthe fittest ). However, the biological terms are used as metaphors rather than in their exact meaning. The population of individuals denotes a set of solution candidates or points of the solution space. Each individual represents a point in the search space which is coded in the individual s representation (genome). The fitness of an individual is usually defined on the basis of the value of the objective function and determines its chances to stay in the population and to be used to generate new solution points. 

For example, a common thread in applications in meteorology, chemistry, or mathematical biology is a natural separability of the objective functions into components of differing complexity (e.g., local and nonlocal interactions). This composition may not only change the relative attractiveness or suitability among different optimization methods, but also lead to very powerful methods for the application at hand when this information is incorporated appropriately. 

In this sense, the constraint-based optimization approach provides a convenient way to efficiently generate quantitative predictions of biological hypotheses formulated in terms of objective functions.5 The value of this approach is in facilitating the systematic prediction-experimental verification-hypothesis modification cycle, ideally leading to new discoveries. 

A) Quick passage of the compound through the biological object without affecting its function. 

Membran systems are known to play an important role in functioning biological objects (in mass transfer processes, passive and active transport of substance, regulation of an endocellular metabolism, in bio-energetics, etc.). Unique properties of biomembranes are caused by their structure, in particular, presence of bimolecular focused layers of lipids. At the same time, one of the main disadvantages of modelling lipid membran systems (monolayers, flat bilayers, liposomes), is their low stability in time and to action of external factors. 

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