Category Great Scientific Discoveries

When was cholera vaccine discovered?

 

          The first vaccine for cholera was developed in the late 19th century. It became the first widely used vaccine ever made in a laboratory. In 1885, Jaume Ferran i Clua developed an early version of this with a live vaccine he isolated from cholera sufferers in Marseilles.

          Waldemar Haffkine later developed another cholera vaccine with milder side effects and tested it in Calcutta between 1893 and 1896.

          The first heat-killed cholera vaccine was developed by Wilhelm Kolle in 1896. Much easier to make, Kolle’s vaccine was used on a large scale in Japan in 1902. Recognized by the WHO as an essential medicine, cholera vaccine has become important for us.

Picture Credit : Google

 

 

Who discovered the hormones?

           Hormones are chemicals such as adrenaline, which control our body and cause our heart to pound in times of stress.

            The first hormone was discovered in 1902 by William Bayliss and Ernest Starling, two British physiologists (people who study how living things work). They found that when food reaches the stomach, a chemical is released into the bloodstream, making the pancreas secrete digestive juices. They called this chemical secretin. The term ‘hormone’ was later coined by Starling. It is derived from the Greek expression meaning ‘setting in motion’.

            Physiology made a great leap when Bayliss and Starling introduced the concept of hormone with recognition of chemical regulation three years later. Even today, our understanding of hormones is a work in progress.

Picture Credit : Google

 

What is the relevance of the chromosome theory of inheritance?

            Wilhelm Hofmeister first observed chromosomes during cell division, as early as 1848. However, the chromosome theory of inheritance is credited to two individuals: the papers by Walter Sutton in 1902 and 1903, and to the independent work done around the same time by Theodor Boveri.

            In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Chromosomes are only visible during cell division.

            The chromosome theory of inheritance is the fundamental unifying theory of genetics which identifies chromosomes as the carriers of genetic material. The theory states that chromosomes are the basis for all genetic inheritance. Chromosomes are seen in all dividing cells and pass from one generation to the next.

Picture Credit : Google

 

Why is the discovery of sulphonamide drugs crucial?

            Before the use of antibiotics, sulphonamides were the only drugs that could kill a wide range of bacteria. In 1932, German bacteriologist Gerhard Domagk discovered the first prontosil, a non-antibiotic anti-bacterial drug. Scientists later realized that this broke down in the body to give a more potent drug, sulphanilamide.

            From 1936, after clinical trials by British doctor Leonard Colebrook, several sulpha drugs were used to save thousands of lives. They are still used when antibiotics are ineffective. For his remarkable achievements in the fight against infections, Domagk received the Nobel Prize for Medicine in 1939.

Picture Credit : Google

 

When were vitamins discovered?

            Our body requires vital elements including carbohydrates, proteins, minerals, fats and vitamins. The discovery of vitamins was a major scientific achievement in our understanding of health and diseases. Research flourished between early 19th century and mid-20th century resulting in plenty of discoveries.

            British biochemist Frederick Hopkins conducted an experiment on rats by feeding them an artificial mixture of the known constituents of milk such as carbohydrates, proteins and fat. He found that rats died when they were fed the mixture of these ingredients, but thrived when fed real milk. Hopkins concluded that to grow, animals need another substance in their diet that was described as accessory factors.

            In 1912, Polish biochemist Casimir Funk identified one of these in rice. On finding that it was a chemical called an amine, he proposed the name ‘vita mine’. Though all vitamins are not amines, the name Funk suggested was adopted after removing the ‘e’ from the end.

Picture Credit : Google

 

Who discovered the double helix structure of DNA?

          The assumption that the nucleic acid in DNA carries genetic information was proved by Oswald Avery by 1943. However, no one could explain how it worked. By the early 1950s, two groups of scientists were on the verge of a breakthrough regarding this.

          At King’s College in London, Rosalind Franklin and Maurice Wilkins were studying DNA using X-ray diffraction as the primary tool. James Watson and Francis Crick however, made crucial advance by proposing that the DNA molecule was made up of two chains of nucleotides paired to form a double helix, like a spiral staircase.

          The double helix structure of DNA was discovered by Watson and Crick in 1953. Double helix refers to the structure formed by double-stranded molecules of nucleic acids and this structure was first published in the journal Nature in 1953.

Picture Credit : Google