Beadle and Tatum trouble! (1 Viewer)

[FC ATAR]

Hi,

I got asked these two questions, as trials prep and I got 0.5/5...

Can anyone suggest how I should respond?

a) Explain why the 'one gene - one protein' hypothesis was changed to 'one gene - one polypeptide' hypothesis. 2 marks
b) Summarise the evidence that led to Beadle and Tatum's 'One gene - one protein' hypothesis. 3 marks

Also, if anyone can provide me with good information on this particular point (Also, the work of Watson, crick, Roosevelt a Wilkins)

Thankyou!

 

[BlueGas]

I feel like that question b) should be the first question but anyways, hope this helps.

a) The theory of 'one gene-one protein' was changed to 'one gene-one polypeptide' because genes are not necessarily responsible for the structure of an entire protein, but for each polypeptide chain making that protein. If you don't understand this answer, it's because I haven't mentioned how they proposed these theories, this is why question b) should be the first question.

b) Before X-ray exposure, the bread mould was able to produce amino acids with the presence of an enzyme. After exposure to X-rays, the bread mould wouldn't grow meaning a particular enzyme couldn't function, it was found that the bread grew healthily after it was supplemented with amino acids. Beadle and Tatum then hypothesized the 'one gene-one protein' because genes code for many proteins, not just enzymes (they actually first hypothesised 'one gene-one enzyme' but was then changed).

 

[FC ATAR]

I feel like that question b) should be the first question but anyways, hope this helps.

a) The theory of 'one gene-one protein' was changed to 'one gene-one polypeptide' because genes are not necessarily responsible for the structure of an entire protein, but for each polypeptide chain making that protein. If you don't understand this answer, it's because I haven't mentioned how they proposed these theories, this is why question b) should be the first question.

b) Before X-ray exposure, the bread mould was able to produce amino acids with the presence of an enzyme. After exposure to X-rays, the bread mould wouldn't grow meaning a particular enzyme couldn't function, it was found that the bread grew healthily after it was supplemented with amino acids. Beadle and Tatum then hypothesized the 'one gene-one protein' because genes code for many proteins, not just enzymes (they actually first hypothesised 'one gene-one enzyme' but was then changed).

So it was changed to "one gene - one polypeptide" through the discovery of thymine being the gene the mould was mutated to not produce?

 

[obliviousninja]

Beadle and Tatum used bread mould to investigate nutritional mutations. Using X-rays, they produced mould that was unable to produce a specific amino acid. The mould was unable to grow unless the amino acid was added. They showed that genes controlled biochemical processes. Their hypothesis was that for each gene there was one enzyme or protein.