explain how it is possible that proteins expressed by differ

explain how it is possible that proteins expressed by different organisms can be functionally interchangeable in different organisms? How does this explain how scientists are able to use a reductionist approach to understand a complex cellular/molecular question?

Solution

All living being on earth (thus, all cells) are thought to be derived from a common ancestor. Solution to many essential challenges that a cell face (such a s synthesis of protein, lipids and DNA) appear to have been achieved in this common ancient ancestor.

The ancestral cells thus possessed set of proteins to carry out these essential functions. Many of the essential challenges faced by modern cells are same as those faced by the ancestral cells, and thus the ancient solutions are still effective. Thus, it is not uncommon for organisms to use proteins and biochemical pathways inherited from their ancestors. These proteins may show some species specific diversification, they still retain the basic biochemical characteristics of the ancestral protein.

For example, homologous proteins often retain their ability to interact with a specific protein target, even in diverse cell types. Because the basic biochemical characteristics are retained, homologous proteins are capable of functionally substituting for one another.

Scientists now have the tools to unravel the biological complexity using reductionist approach. The reductionist method of dissecting biological systems into their constituent parts has been effective on explaining the chemical basis of numerous living processes. Also, animal models are incorporated to study the fact that homologous proteins are capable of substituting for one another.