Protien as genetic inheritance?

[Jikx]

I'm trying to think of a nice topic to do for an essay, it has to be something that was believed to be true, but was proven to be something else due to scientific advances.

I want to do something a bit different from the usual darwin theory / Newton laws. I heard that it was once believed that proteins held the key to inhertitable traits? Anyone have any info on that? Thoughts appreciated.


thanks..

 

[Another God]

Thats actually a really good topic. (Other possible suggestions for topics could be about Phlogiston (old explanation for combustion), or Caloric Fluid (explanation for heat))

As for the proteins as Genetic material, I believe it was the more favoured option over DNA for a long time because the 20 Amino Acids showed the right sort of diversity expected of something like Genetic material. DNA had only 4 bases, and that seemed to small an amount of variety to result in the huge range of phenotypic differences we see.

I know that it can be proven that Proteins aren't the genetic material by radioactivly labelling the amino acids used by a virus to make its proteins, and then allowing one such radioactively labeled virus to infect a cell. Since the virus infects the cell by injecting its genetic material, if proteins were that material, then the radioactively labels should be visible inside the cell. They are not.

Thats my off the head knowledge of the topic. I think Watson or Crick wrote a book about what happened around their discovery of the DOuble Helix structure of DNA, and maybe they go into some back ground history of how why when etc which led up to the victory by DNA...?

 

[ravenprp]

Proteins were once believed to be the key to genetic inheritance due to their complex structure and involvement in many cellular processes. However, with the advancements in genetics and molecular biology, it has been proven that DNA is the main carrier of genetic information and plays a crucial role in inheritance.

The idea of proteins as the basis of inheritance can be traced back to the late 19th century when scientists were trying to understand the mechanisms behind heredity. It was believed that proteins, being the most complex molecules in the cell, must hold the genetic code. This theory was supported by the fact that proteins were found to be present in both the nucleus and the cytoplasm, where genetic material was thought to be located.

In the early 20th century, the discovery of nucleic acids, specifically DNA, challenged this belief. Through experiments with bacteria and viruses, scientists were able to demonstrate that DNA, not proteins, was responsible for passing on genetic information. This was further supported by the work of Rosalind Franklin and Maurice Wilkins, who used X-ray crystallography to reveal the double helical structure of DNA.

The final nail in the coffin for the protein-based inheritance theory came with the discovery of the genetic code in the 1960s. Scientists were able to decipher the code that translates the sequence of nucleotides in DNA into the sequence of amino acids in proteins. This clearly showed that DNA, not proteins, was the carrier of genetic information.

Today, it is well established that DNA is the primary molecule responsible for inheritance. However, proteins still play a crucial role in gene expression and regulation. They act as enzymes, hormones, and structural components in the cell, all of which are essential for maintaining life. Without proteins, DNA would not be able to carry out its functions effectively.

In conclusion, the belief that proteins held the key to genetic inheritance was once widely accepted but has since been disproven by scientific advances. DNA has been shown to be the main carrier of genetic information, but proteins continue to play a vital role in the expression and regulation of genes. This is a perfect example of how scientific discoveries and advancements can challenge and change our understanding of the world around us.