What is Molecular Biology？

What is Molecular Biology?

What is Molecular Biology? A trivial definition of Molecular Biology is “experimental study of the molecular basis of Life”. The three important points in this definition are

1) experimental;

2)molecular;

3) Life.

“Molecular” should be clear (it refers to the “chemical” level of organization

of the matter)，but what is “experimental” and what is “Life”?

In fact, there are only three functional principles defining life that all life forms must perform:

1) the ability to extract from the environment and process energy (e) and matter (m), — we call it “metabolism”, or (e+m) acquisition/processing.

2) the ability to produce independently-functioning and almost exact copies of itself, — we call it self-replication. Functionally, Life can be described as self-replication of metabolism. Or metabolism-supported self-replication, if you prefer the other emphasis.

3) (as a prerequisite of the first two) the ability to separate itself from the environment and to form uniform-size entities, called cells, that metabolize and replicate independently of other such entities. We will return to the cellular organization of life later.

To sum up, all life forms known today display three separate aspects: the structure (cell),the chemistry (metabolism) and the information (the genome). But this is not it, because there is also Environment and there is also Time, which define one more important aspect of Life.

Indeed, not only all forms of Life possess cellular-based metabolism and self-replication,

but they also constantly strive to excel relative each other in the Environment through the

process of Evolution (propagation of the fittest). All three aspects of Life (structural, chemical and informational) would be impossible if the organism cannot secure resources to maintain and perform them.