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Archive for the tag “vital force”

About the origin of Microbiology

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The vital force or vitalism mentioned for Wöhler meant, at that time, also that living organisms can arise spontaneously from nonliving matter (e.g. flies on putrid meat and microorganisms in broth), i.e. theory of spontaneous generation. Noted chemists like Wöhler did not know the role of microorganisms during the change of sugar to alcohol, i.e. fermentation, but rather saw it as a mere chemical change that my require oxygen to activate some vital force. It took several decades to definitely discredit the theory of spontaneous generation in the 19th century by the work of Louis Pasteur after the pioneering study to research this theory by Lazzarro Spallanzani in 1768.

Although microorganisms could be seen by the aid of microscope in the 17th century by Antonie van Leeuwenhoek, it was not until the 19th century that microbiology began to develop as a truly scientific discipline. Pasteur established that living microorganisms are responsible for the chemical changes that occur during fermentation and meanwhile discovered that some microorganisms carry out anaerobic metabolism, i.e. in absence of air, or more specifically in absence of molecular oxygen.

During the same period of Pasteur’s studies, Robert Koch was developing methods for growing individual types of microorganisms in the laboratory. These pure culture methods permitted him to establish the relationship between a microorganism and an infectious disease like anthrax, tuberculosis and cholera, i.e. the germ theory of disease, which was previously proposed by Koch’s mentor, Jacob Henle, at the University of Göttingen.

References:

–          Ronald M. Atlas, Principles of Microbiology, 1. edition, 1995, Mosby-Year Book, Inc.

–          Online Wikipedia.

A note on the emergence of Biochemistry

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Human knowledge is cumulative in nature so that siblings inherit knowledge and experiences from their parents and ancestors. However, it is not until those unfounded myths and ideas are replaced by evidence-based information and concepts that our lives improve and advance. This statement is correct for the “phlogiston” and the “vital force” theories that would – if not debunked by Lavoisier and Wöhler, respectively – stuck our perception for chemistry up till now.

Lavoisier (1743 – 1794) could show in hand of self made equipments such as relatively fair balances that the mass of reactants must equal that of products in a given chemical change, i.e. law of conservation of mass. In this way defeated Lavoisier the very popular idea in his time that matter could be gained or lost during chemical reaction as a vague concept named phlogiston was accused for this argument. Notably during analysis of the combustion phenomenon, Lavoisier had, in the contrary, constructed his experiments so that all the materials could be accounted for during and after the reaction. By this law deserved Lavoisier the name as father of modern chemistry. Wöhler (1800 – 1882) could for the first time synthesize urea (an organic substance known to happen in living organisms only, i.e. in vivo) from inorganic substances, namely ammonia and cyanic acid, in the laboratory, i.e. in vitro. This achievement by Wöhler demolished the idea that organic substances can happen only inside living organism thanks to a mysterious vital force. By this way opened Wöhler a wonderful discipline to courageously study and investigate the matter of the living world, i.e. Biochemistry.

It came then to realize that the matter of the livings not only can be reliably studied by the same means as exactly as the nonliving matter could be but also it obeys the same rules and laws of the nonliving matter. Such fact was founded by some physicists such as Bohr (1885 – 1962), Schrödinger (1887 – 1961), and Max Delbrück (1906 – 1981). Delbrück grounded a group called the Phage Group that believed that their bacteriophage model (bacterial virus) bears much hope to unravel crucial rules in studying the genetic material. Again, we are at the door of a new fascinating world of Molecular Biology.

After this very brief introduction we would see that Biochemistry is a relatively new discipline that concerns everything about living matter at the level of molecules and atoms. We owe our knowledge in Biochemistry to chemists and physicists, as mentioned above, and to biologists as well. The generalization by Schleiden and Schwann in 1839 that all living organisms are made of small structural and functional units called cells, i.e. the cell theory, has made possible all subsequent progresses in our Biology and Biochemistry. It is then worthy noting that none of the scientific disciplines is independent of the others, e.g., when physicists ground for Molecular Biology and mathematicians for Biostatistics and Gene Banks and Bioinformatics.

Useful references:

–          TA Brown, Genetics, a molecular approach, 3. Edition, Stanley Thornes (Publishers) Ltd.

–          Online Wikipedia.

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