The Structure of DNA
The structure of DNA is remarkably simple compared with that of proteins. It is made up of 2 strands of nucleic acid - long chains of nucleotides. As shown here:
Base Pairs
It was know from the early stages of the discovery of DNA that there where patterns in the quantities of each base presents. For example, the amount (%) of Adenine found in any sample is always equal to the amount of Thymine. The amount of Cytosine is always equal to that of Guanine. It is no well established that this is because the bases always arise in the same pairs.
Adenine always pairs with Thymine and Cytosine always with Guanine. You must remember these pairings and you should be able to interpret data relating to the amounts of each present.
To remember:
Adenine always pairs with Thymine and Cytosine always with Guanine. You must remember these pairings and you should be able to interpret data relating to the amounts of each present.
To remember:
Apple - Tart
Chocolate - Gâteaux
(or my why - "the curly ones go together")
Chocolate - Gâteaux
(or my why - "the curly ones go together")
There are good reasons for these pairings. First of all there is the physical size of the bases. In order to maintain the regular structure that we know DNA has, the base must be made up of a purine and a pyrimidine.
Which base bonds with which is determined by the number of Hydrogen bonds they are able to make.
This is all summed up nicely in this catch little number