Question

What was the idea of Paul Ehrlich?

A. Chemicals that would adversely affect the invading bacteria but not the host, can be used for the treatment of diseases caused by the bacteria.

B. Chemicals which would adversely affect the invading bacteria but not the host, cannot be used for the treatment of diseases caused by the bacteria.

C. Chemicals which would adversely affect the invading bacteria but not the guest, cannot be used for the treatment of diseases caused by the bacteria.

D. Chemicals which would adversely affect the invading bacteria also the guest, cannot be used for the treatment of diseases caused by the bacteria.

Answer 1

Hint: Paul Ehrlich was a German biologist of the nineteenth century who had discovered many medicines for the bacterial diseases. He was awarded the Nobel Prize for his contribution in medicine. He was the first to discover treatment for syphilis.

Complete step by step answer: Let’s discuss the discovery of Paul in the field of medicine. In the nineteenth century, the chemicals that adversely affect invading bacteria but not the host were searched. Paul Ehrlich came up with this idea. He began to investigate arsenic based structure in order to produce less toxic substances for treating Syphilis. He developed the medicine for syphilis, that is, arsphenamine (also known as salvarsan). For the discovery of this medicine, he was honored with the Nobel Prize. It was the first effective treatment discovered for syphilis. Although the medicine is toxic to human beings, its effect on spirochete, bacteria which causes syphilis is much greater than on human beings.
Therefore, we can say that Paul's idea was to discover the chemicals that adversely affect invading bacteria but not the host.
Hence, option A is correct.

Additional Information:
Paul also worked on azo dyes during the discovery of his medicine (salvarsan). He also noted the similarity in structures of azodyes and salvarsan. The ${\rm{ - As}} = {\rm{As - }}$ bond of salvarsan is similar to $ - {\rm{N}} = {\rm{N}} - $ of azodyes considering the presence of arsenic atom in the place of nitrogen. He also noted that tissues get colored by dyes selectivity. Therefore, he searched for compounds that possess resemblance in structure to azo dye and so that it bind selectively to the bacteria.

Note: The real revolution in antibacterial therapy began with the discovery of Alexander Fleming, that is, penicillin which can cure bacterial infection. It was the first antibiotic discovered. Antibiotics are drugs used to treat infection as they are less toxic to animals and humans.