Biochemical Engineering Fundamentals, Part 1 - Bailey J., Ollis D. 1989

Introduction to Microbiology
Biophysics and Cell Theory

Microbiology is the science that studies living organisms invisible to the naked eye. As a rule, the diameter of microorganisms does not exceed 0.1 mm. Today, we know that even the simplest microorganisms house a highly complex system of remarkably efficient and highly coordinated chemical reactors, as well as information, control, regulatory, and mass transfer systems. These findings have been obtained through numerous experimental studies using Methods borrowed from the Physical and Chemical sciences. Since this approach has proved extremely fruitful, the applicability of the fundamental principles of chemistry and physics to biological systems is currently a widely accepted working hypothesis within the life sciences. To more clearly define the scientific field in which biological problems are solved using physical methods, the term "biophysics" is sometimes used.

A turning point in our understanding of living systems came in 1838, when Schleiden and Schwann first formulated the Cell Theory, which postulates that all living systems are composed of Cells and their products. Thus, METABOLISM/2.html">THE CONCEPT OF the basic unit or the fundamental building block of life was established. This concept of a structural element common to All living organisms allows us to divide the Study of Living systems into two stages: first, investigating the cells that make up the system, and then, on this basis, attempting to understand The Structure of the entire Organism.

The validity of this division of research is based on the fact that cells isolated from A wide variety of organisms share much in common, both in terms of their structure and their Functions. Therefore, data obtained from Experiments on the cells of one organism can, in many cases, be successfully extrapolated to other cell types. The existence of features common to all cells also simplifies our task of studying The behavior of microorganisms. By focusing on the most universal cellular functions, we can build a foundation for understanding how all living systems function.

We would not want the reader to get the impression, however, that all cells are identical. On the contrary, Muscle cells, for example, differ sharply from eye or Brain cells. Similarly, There are many types of single-celled organisms which, According to the features of their Organization described below, can be divided into two main groups.