Syracuse: DNA Paper

Date:
1959
Reference:
PP/CRI/E/1/7/2
Catalogue details

Licence: In copyright

Credit: Syracuse: DNA Paper. Source: Wellcome Collection.

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    (• J We also believe that In a bacteriophage, it is very likely that it carries the specificity because hardly any protein goes in - only just a little - when th© phage infects the cell. One has to, of course, make the general point with which I am sure you are all familiar, that DNA stands for a class of molecules. It is not just one molecule. We had better start out, so we know where we are, by writing down the general formula for DNA which we can do this way in a highly abbreviated notation like this. DNA is a high molecular weight molecule of which this is the backbone -- going phosphate - sugar - phosphate - sugar - phosphate - sugar, the sugar of course being the deoxy ribos®. To every sugar ther i is attached a base. So far, everything we have drawn, is com pletely regular. That is to say, this backbone repeats and this method of attachment repeats. But, as I am sure you know, there are four sorts of bases -- adenine, thymine, guanine and cytosine. It was shown early by Chargaff that the amount of adenine equals the amount of thymine and the amount of guanine equals the amount of cytosine. Now, there is recently a little virus which is the exception to this rule - which is a very Interesting case but which I won*t talk about although it does fit in quite nicely with ideas now that we have about replication, etc.